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  • 1.
    Alimadadi, H.
    et al.
    Chalmers University of Technology.
    Ahmadi, M.
    University of Tehran.
    Aliofkhazraei, M.
    Tarbiat Modares University.
    Younesi, S.R.
    Royal Institute of Technology (KTH).
    Corrosion properties of electrodeposited nanocrystalline and amorphous patterned Ni–W alloy2009In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, ISSN 0261-3069, Vol. 30, no 4, p. 1356-1361Article in journal (Refereed)
    Abstract [en]

    Nickel-tungsten with satisfactory corrosion properties is a promising alloy to replace hard chromium. Relatively high adhesion between copper substrate and electrodeposited Ni-W alloy results in patterned morphology due to crack formation. In this work, corrosion resistance of patterned Ni–W alloys comprising 0-26 at.%.W were studied by potentiodynamic polarization and EIS in a medium containing Cl-. It is shown that corrosion resistance of single phase Ni-W is superior to amorphous and dual phase coated layers. It is also found that crack density is the dominant affecting factor on corrosion resistance of amorphous Ni-W alloys.

  • 2.
    Bhattacharjee, Rahul
    et al.
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Jana, Ankit
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Nandi, Aditya
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Sinha, Adrija
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Bhattacharjee, Arkadyuti
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Mitra, Sagnik
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Kar, Sulagna
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Dey, Abhijit
    Presidency Univ, Dept Life Sci, 86-1 Coll St, Kolkata 700073, West Bengal, India..
    Singh, Sushil Kumar
    Assam Agr Univ, Dept Agr Biotechnol, DBT NECAB, Jorhat 785013, Assam, India..
    Varma, Rajender S.
    Palacky Univ Olomouc, Czech Adv Technol & Res Inst, Reg Ctr Adv Technol & Mat, Slechtitelu 27, Olomouc 78371, Czech Republic..
    Panda, Pritam Kumar
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Suar, Mrutyunjay
    Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Verma, Suresh K.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Kalinga Inst Ind Technol KIIT DU, KIIT Sch Biotechnol, Bhubaneswar, Odisha, India..
    Synergy of nanocarriers with CRISPR-Cas9 in an emerging technology platform for biomedical appliances: Current insights and perspectives2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 224, article id 111415Article in journal (Refereed)
    Abstract [en]

    Genetic editing technologies have emerged as a potential therapeutic tool in various biomedical fields owing to their applications against cancer, neurological diseases, diabetes, autoimmune disorder, muscu-lar dystrophy, bacterial infections (AMR), and cardiovascular diseases. CRISPR is one such valuable genetic editing tool with extensive therapeutic appliances but with a major challenge in terms of deliv-ery. Herein, we have strived to exploit a synergy of nanocarriers and CRISPR against the aforementioned diseases for their medical applications and explicated their clinical significance including the enhanced delivery via endosomal escape and environmental factors such as light, pH, and stimuli. In addition to highlighting the delivery strategies of nano-carriers for CRISPR and their characterization, we have expounded on the reliant factor of the CRISPR-Cas Complex.

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  • 3.
    Choi, Young Won
    et al.
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Dong, Zhihua
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Li, Wei
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Schönecker, Stephan
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Kim, Hansoo
    Korea Univ, Inst High Technol Mat & Devices, Seoul 02841, South Korea.
    Kwon, Se Kyun
    Pohang Univ Sci & Technol, Dept Phys, Pohang 37673, South Korea.
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden;Wigner Res Ctr Phys, Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary.
    Predicting the stacking fault energy of austenitic Fe-Mn-Al (Si) alloys2020In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 187, article id 108392Article in journal (Refereed)
    Abstract [en]

    Aluminum and silicon are common alloying elements for tuning the stacking fault energy (SFE) of high Mn steels. Today the theoretical investigations on the Fe-Mn-Al/Si systems using Density Functional Theory (DFT) are very scarce. In the present study, we employ a state-of-the-art longitudinal spin fluctuations (LSFs) model in combination with DFT for describing the magnetic effects in Fe-Mn based alloys at finite temperature. We find that the traditional DFT-floating spin results fail to explain the experimental trends. However, the DFT-LSFs approach properly captures the Al-induced increase and Si-induced decrease of the SFE of the base alloy in line with the room-temperature observations. This finding highlights the importance of LSFs in describing the Al/Si effects on the SEE of Fe-Mn based alloys. We point out that the effects of the non-magnetic Al and Si additions on the SEE are in fact determined by the magnetic state of the host matrix. In addition, we estimate the role of carbon addition in the alloying effects of Al and Si. The present results provide a convenient pathway to access the important mechanical parameters for designing advanced high-strength alloys. 

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  • 4.
    Dai, J. H.
    et al.
    Royal Inst Technol, Appl Mat Phys, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden;Harbin Inst Technol Weihai, Sch Mat Sci & Engn, 2 West Wenhua Rd, Weihai 264209, Peoples R China.
    Li, W.
    Royal Inst Technol, Appl Mat Phys, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden.
    Song, Y.
    Harbin Inst Technol Weihai, Sch Mat Sci & Engn, 2 West Wenhua Rd, Weihai 264209, Peoples R China.
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Appl Mat Phys, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden.
    Theoretical investigation of the phase stability and elastic properties of TiZrHfNb-based high entropy alloys2019In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 182, article id UNSP 108033Article in journal (Refereed)
    Abstract [en]

    First principles calculations are performed to study the effects of alloying elements (X = Al, Si, Sc, V, Cr, Mn, Cu, Zn, Y. Mo, Ta, W and Re) on the phase stability and elastic properties of TiZrHfNb refractory high entropy alloys. Both equimolar and non-equimolar alloys are considered. It is shown that the calculated lattice parameters, phase stability and elastic moduli of equimolar TiZrHfNbX are consistent with the available experimental and theoretical results. The substitutions of alloying elements at Ti, Zr, and Hf sites with various contents show similar effects on the phase stability and elastic properties of the TiZrHINb-based alloys. The substitutions on Nb site are found to generally decrease the stability of body centered cubic phase. Close connections between the charge densities at the Wigner-Seitz cell boundary and the bulk moduli of TiZrHfNb-based alloys are found. The present results provide a quantitative model for exploring the phase stability and elastic properties of TiZrHINb-based alloys from the electronic structure viewpoint. (C) 2019 The Authors. Published by Elsevier Ltd.

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  • 5.
    Davydova, Alexandra
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Eriksson, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Chen, R
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rudisch, Katharina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Persson, C.
    Univ Oslo, Dept Phys, Ctr Mat Sci & Nanotechnol, POB 1048, NO-0316 Oslo, Norway;KTH Royal Inst Technol, Dept Mat Sci & Engn, S-10044 Stockholm, Sweden.
    Scragg, Jonathan J.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thio-olivine Mn2SiS4 thin films by reactive magnetron sputtering: Structural and optical properties with insights from first principles calculations2018In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 152, p. 110-118Article in journal (Refereed)
    Abstract [en]

    Thio-olivines such as (Fe,Mn)(2)(Si,Ge)S-4 have been proposed as candidate earth-abundant materials for single and multi-junction solar cells. In this work we present the first investigation of Mn2SiS4 thin films prepared by reactive magnetron sputtering deposition, using a composition grading approach. Precursor instability in ambient conditions is observed, revealing the oxidation/hydrolysis of Si-S bonds from the as-deposited film as a blocking mechanism for the ternary compound formation. Structural, morphological and optical properties of the annealed Mn2SiS4 films are reported for the first time. Resulting Mn2SiS4 films have orthorhombic Pnma structure and are polycrystalline. Raman active modes at 325 nm excitation are observed at 262, 320, 400 and 464 cm(-1). From room temperature photoluminescence at 532 nm excitation the band gap is estimated to be about 1.9 eV, but a high optical absorption coefficient of > 10(4) cm(-1) was only obtained at E > 2.8 eV.First principles calculations are used for better understanding of opto-electronic properties. From the calculations, Mn2SiS4 is suggested to have a band gap of about 1.73-1.86 eV depending on the magnetic configuration of Mn and slight indirect nature. The slow absorption onset is interpreted by strong anisotropy due to one of the components of the dielectric function. 

  • 6.
    Ericsson, A.
    et al.
    Lund Univ, Div Solid Mech, POB 118, SE-75120 Lund, Sweden..
    Pacheco, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindwall, J.
    Luleå Tech Univ, Mech Solid Mat, SE-97187 Luleå, Sweden..
    Hallberg, H.
    Lund Univ, Div Solid Mech, POB 118, SE-75120 Lund, Sweden..
    Fisk, M.
    Lund Univ, Div Solid Mech, POB 118, SE-75120 Lund, Sweden.;Malmö Univ, Mat Sci & Appl Math, SE-20506 Malmö, Sweden..
    Transient nucleation in selective laser melting of Zr-based bulk metallic glass2020In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 195, article id 108958Article in journal (Refereed)
    Abstract [en]

    The crystallization rate during selective laser melting (SLM) of bulk metallic glasses (BMG) is a critical factor in maintaining the material's amorphous structure. To increase the understanding of the interplay between the SLM process and the crystallization behavior of BMGs, a numerical model based on the classical nucleation theory has been developed that accounts for the rapid temperature changes associated with SLM. The model is applied to SLM of a Zr-based BMG and it is shown that the transient effects, accounted for by the model, reduce the nucleation rate by up to 15 orders of magnitude below the steady-state nucleation rate on cooling, resulting in less nuclei during the build process. The capability of the proposed modelling approach is demonstrated by comparing the resulting crystalline volume fraction to experimental findings. The agreement between model predictions and the experimental results clearly suggests that transient nucleation effects must be accounted for when considering the crystallization rate during SLM processing of BMGs.

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  • 7.
    Fritze, Stefan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Chen, M.
    Swiss Fed Inst Technol, Lab Nanomet, Vladimir Prelog Weg 5, CH-8093 Zurich, Switzerland..
    Riekehr, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Osinger, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Sortica, Mauricio A.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Srinath, Aishwarya
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Menon, Ashok S.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Wheeler, J. M.
    Swiss Fed Inst Technol, Lab Nanomet, Vladimir Prelog Weg 5, CH-8093 Zurich, Switzerland..
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Magnetron sputtering of carbon supersaturated tungsten films-A chemical approach to increase strength2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 208, article id 109874Article in journal (Refereed)
    Abstract [en]

    Tungsten (W)-based materials attract significant attention due to their superior mechanical properties. Here, we present a chemical approach based on the addition of carbon (C) for increased strength via the combination of three strengthening mechanisms in W thin films. W:C thin films with C concentrations up to-4 at.% were deposited by magnetron sputtering. All films exhibit a body-centred-cubic structure with strong texture and columnar growth behaviour. X-ray and electron diffraction measurements suggest the formation of supersaturated W:C solid solution phases. The addition of C reduced the average column width from-133 nm for W to-20 nm for the film containing-4 at.% C. The column refinement is explained by a mechanism where C acts as re-nucleation sites. The W film is-13 GPa hard, while the W:C films achieve a peak hardness of-24 GPa. The W:C films are-11 GPa harder than the W film, which is explained by a combination of grain refinement strengthening, solid solution strengthening and increased dislocation density. Additional micropillar compression tests showed that the flow stress increased upon C addition, from-3.8 to-8.3 GPa and no brittle fracture was observed.

  • 8.
    Fritze, Stefan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Hans, M.
    Materials Chemistry, RWTH Aachen University, Aachen, Germany.
    Riekehr, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Osinger, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Schneider, J.M.
    Materials Chemistry, RWTH Aachen University, Aachen, Germany.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Influence of Carbon on Microstructure and Mechanical Properties of Magnetron Sputtered TaW Coatings2020In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 196, article id 109070Article in journal (Refereed)
    Abstract [en]

    (Ta,W) and (Ta,W):C films with-5 at.% C were deposited by non-reactive magnetron sputtering. They crystallised in a bcc structure with a columnar microstructure. The solid solubility of C in (Ta,W) alloys is very low, which suggests that the (Ta,W):C films are supersaturated with respect to carbon. This was confirmed by diffraction and atom probe tomography (APT) showing that carbon is in the as-deposited (Ta,W):C films homogeneously distributed in the structure without carbide formation or carbon segregation. Annealing at 900 degrees C for 2 h showed no significant column coarsening but an increased defect density at the column boundaries in the (Ta,W):C films. The films were still supersaturated with respect to carbon but APT showed a partial segregation of carbon presumably to defect-rich column boundaries after annealing. The (Ta,W) films exhibited a hardness of-12-13 GPa. Alloying with carbon increased the hardness to-17 GPa. The hardness increased to-19 GPa for the annealed (Ta,W):C films. This annealing-induced hardness increase was explained by C segregation to the more defect-rich column boundaries, which restricts dislocation movements. (Ta,W):C coatings may be a potential alternative to ceramic coatings, worth exploring further by small scale mechanical testing to investigate if these materials are ductile.

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  • 9.
    Glechner, T.
    et al.
    TU Wien, Christian Doppler Lab Surface Engn High Performan, Vienna, Austria..
    Hudak, O. E.
    TU Wien, Christian Doppler Lab Surface Engn High Performan, Vienna, Austria..
    Wojcik, T.
    TU Wien, Christian Doppler Lab Surface Engn High Performan, Vienna, Austria..
    Haager, L.
    TU Wien, Inst Chem Technol & Analyt, A-1060 Vienna, Austria..
    Bohrn, F.
    TU Wien, Inst Chem Technol & Analyt, A-1060 Vienna, Austria..
    Hutter, H.
    TU Wien, Inst Chem Technol & Analyt, A-1060 Vienna, Austria..
    Hunold, O.
    Oerlikon Surface Solut AG, Oerlikon Balzers, FL-9496 Balzers, Liechtenstein..
    Ramm, J.
    Oerlikon Surface Solut AG, Oerlikon Balzers, FL-9496 Balzers, Liechtenstein..
    Kolozsvari, S.
    Plansee Composite Mat GmbH, D-86983 Lechbruck, Germany..
    Pitthan, Eduardo
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Riedl, H.
    TU Wien, Christian Doppler Lab Surface Engn High Performan, Vienna, Austria.;TU Wien, Inst Mat Sci & Technol, A-1060 Vienna, Austria..
    Influence of the non-metal species on the oxidation kinetics of Hf, HfN, HfC, and HfB2 coatings2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 211, article id 110136Article in journal (Refereed)
    Abstract [en]

    The influence of the non-metal species on the oxidation resistance of transition metal ceramic based thin films is still unclear. For this purpose, we thoroughly investigated the oxide scale formation of a metal (Hf), carbide (HFC0.96), nitride (HfB1.5), and boride (HfB2.3) coating grown by physical vapor deposition. The non-metal species decisively affect the onset temperature of oxidation, ranging between 550 degrees C for HfC0.96 to 840 degrees C for HfN1.5. HfB2.3 and HfN1.5 obtain the slowest oxide scale kinetic following a parabolic law with k(p) values of 4.97.10(-10) and 5.66.10(-11) kg(2) m(-4) s(-1) at 840 degrees C, respectively. A characteristic feature for the oxide scale on Hf coatings, is a columnar morphology and a substantial oxygen inward diffusion. HfC0.96 reveals an ineffective oxycarbide based scale, whereas HfN(1.5 )features a scale with globular HfO2 grains. HfB(2.3 )exhibits a layered scale with a porous boron rich region on top, followed by a highly dense and crystalline HfO2 beneath. Furthermore, HfB(2.3 )presents a hardness of 47.7 +/- 2.7 GPa next to an exceptional low inward diffusion of oxygen during oxidation. This study showcases the strong influence of the non-metallic bonding partner despite the same metallic basis, as well as the huge potential for HfB2 based coatings also for oxidative environments.

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  • 10.
    Gleich, Stephan
    et al.
    Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany..
    Soler, Rafael
    Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany..
    Fager, Hanna
    Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany.;Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Bolvardi, Hamid
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Achenbach, Jan-Ole
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Hans, Marcus
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Schneider, Jochen M.
    Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany.;Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Dehm, Gerhard
    Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany..
    Scheu, Christina
    Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany.;Rhein Westfal TH Aachen, Mat Analyt, Kopernikusstr 10, D-52074 Aachen, Germany..
    Modifying the nanostructure and the mechanical properties of Mo2BC hard coatings: Influence of substrate temperature during magnetron sputtering2018In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 142, p. 203-211Article in journal (Refereed)
    Abstract [en]

    A reduction in synthesis temperature is favorable for hard coatings, which are designed for industrial applications, as manufacturing costs can be saved and technologically relevant substrate materials are often temperature-sensitive. In this study, we analyzed Mo2BC hard coatings deposited by direct current magnetron sputtering at different substrate temperatures, ranging from 380 degrees C to 630 degrees C. Transmission electron microscopy investigations revealed that a dense structure of columnar grains, which formed at a substrate temperature of 630 degrees C, continuously diminishes with decreasing substrate temperature. It almost vanishes in the coating deposited at 380 degrees C, which shows nanocrystals of similar to 1 nm in diameter embedded in an amorphous matrix. Moreover, Argon from the deposition process is incorporated in the film and its amount increases with decreasing substrate temperature. Nanoindentation experiments provided evidence that hardness and Young's modulus are modified by the nanostructure of the analyzed Mo2BC coatings. A substrate temperature rise from 380 degrees C to 630 degrees C resulted in an increase in hardness (21 GPa to 28 GPa) and Young's modulus (259 GPa to 462 GPa). We conclude that the substrate temperature determines the nanostructure and the associated changes in bond strength and stiffness and thus, influences hardness and Young's modulus of the coatings.

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  • 11.
    Gopalan, Hariprasad
    et al.
    Max Planck Inst Eisenforsch GmbH, Dusseldorf, Germany.;Karlsruhe Inst Technol, Inst Appl Mat FML, Karlsruhe, Germany..
    Marshal, Amalraj
    Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany.;Fac Sci & Tech St Jerome, IM2NP, UMR 7334, Marseille, France..
    Hans, Marcus
    Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Cautaerts, Niels
    Max Planck Inst Eisenforsch GmbH, Dusseldorf, Germany..
    Breitbach, Benjamin
    Max Planck Inst Eisenforsch GmbH, Dusseldorf, Germany..
    Völker, Bernhard
    Max Planck Inst Eisenforsch GmbH, Dusseldorf, Germany.;Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany.;Mat Ctr Leoben, Leoben, Austria..
    Kirchlechner, Christoph
    Max Planck Inst Eisenforsch GmbH, Dusseldorf, Germany.;Karlsruhe Inst Technol, Inst Appl Mat, Karlsruhe, Germany..
    Schneider, Jochen M.
    Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany..
    Dehm, Gerhard
    Max Planck Inst Eisenforsch GmbH, Dusseldorf, Germany..
    On the interplay between microstructure, residual stress and fracture toughness of (Hf-Nb-Ta-Zr)C multi-metal carbide hard coatings2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 224, article id 111323Article in journal (Refereed)
    Abstract [en]

    The development of sputtered coatings with improved hardness-toughness property combination is widely sought after. Multi-element ceramic carbide (Hf-Nb-Ta-Zr)C coatings with excess carbon, synthesized by DC co-sputtering is presented in this study as a promising candidate to achieve this objective. The specific roles of microstructure and residual stress are decoupled in order to understand their influence on the mechanical properties. Extensive mechanical characterization through in situ testing of focused ion beam fabricated microcantilevers and nanoindentation based approaches are adopted to quantitatively separate the effect of residual stresses on the fracture toughness of the (Hf-Nb-Ta-Zr)C coatings. Residual stress free, microcantilever testing in notched and unnotched conditions, in combination with microstructural characterization unambiguously reveals the intrinsic mechanical behavior of coatings, which solely depend on the microstructure. On the other hand, nanoindentation based testing techniques probe the influence of residual stress and microstructure on the measured mechanical properties. The segregation and thickening of carbon-rich clusters, especially to the grain boundaries with increasing deposition temperatures is speculated to lead to substantial degradation in all mechanical properties measured. An easier fracture path through grain boundaries leads to a reduction in fracture resistance, which is possibly related to carbon enrichment.

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  • 12. Hassila, C.J.
    et al.
    Paschalidou, Eirini-Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Harlin, P.
    Wiklund, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Potential of nitrogen atomized alloy 625 in the powder bed fusion laser beam process2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 221, p. 110928-110928, article id 110928Article in journal (Refereed)
    Abstract [en]

    Powder based metal additive manufacturing processes like Powder Bed Fusion – Laser Beam utilize gasatomized metal powders as feedstock material. Typically, for nickel-based alloys such as Alloy 625, argongas is used during the atomization process. Considering the larger environmental impact of argon gascompared to nitrogen gas, and the increasing use of gas atomized metal powders, the environmentalimpact of powder based additive manufacturing techniques could be mitigated if gas atomization ofalloys such as Alloy 625 using nitrogen was possible. This work investigates the feasibility of tailoringan alloy to allow atomization using nitrogen gas while remaining within the Alloy 625 specification.This is achieved by limiting the nitrogen pick-up during the atomization process, primarily by reducingthe titanium content. The metallurgical implications of this tailored alloy and the subsequent atomizationusing nitrogen, as well as the attained microstructure from the Powder Bed Fusion – Laser Beam processis investigated and compared to a more common 625 alloy composition which was atomized usingargon. Furthermore, the microstructural development of the alloys after heat treatments are evaluated.Lastly corrosive properties, as well as tensile and impact properties are evaluated both in the as-builtand hot isostatic pressed condition.

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  • 13.
    Huang, Shuo
    et al.
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Li, Wei
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Li, Xiaoqing
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Schonecker, Stephan
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Bergqvist, Lars
    Royal Inst Technol, Dept Mat & Nano Phys, Electrum 229, SE-16440 Kista, Sweden..
    Holmström, Erik
    Sandvik Coromant R&D, S-12680 Stockholm, Sweden..
    Varga, Lajos Karoly
    Wigner Res Ctr Phys, Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.;Wigner Res Ctr Phys, Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    Mechanism of magnetic transition in FeCrCoNi-based high entropy alloys2016In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 103, p. 71-74Article in journal (Refereed)
    Abstract [en]

    First-principles alloy theory and Monte-Carlo simulations are performed to investigate the magnetic properties of FeCrCoNiAlx high entropy alloys. Results show that face-centered-cubic (fcc) and body-centered-cubic (bcc) structures possess significantly different magnetic behaviors uncovering that the alloy's Curie temperature is controlled by the stability of the Al-induced single phase or fcc-bcc dual-phase. We show that the appearance of the bcc phase with increasing Al content brings about the observed transition from the paramagnetic state for FeCrCoNi to the ferromagnetic state for FeCrCoNiAl at room-temperature. Similar mechanism is predicted to give rise to room-temperature ferromagnetism in FeCrCoNiGa high entropy alloy.

  • 14.
    Kaplan, Maciej
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Srinath, Aishwarya
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Riekehr, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Hjörvarsson, Björgvin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Fritze, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Combinatorial design of amorphous TaNiSiC thin films with enhanced hardness, thermal stability, and corrosion resistance2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 220, article id 110827Article in journal (Refereed)
    Abstract [en]

    Amorphous TaNiSiC and TaNiC films (with varying Ta/Ni and Si/C ratios) were deposited using combinatorial magnetron sputtering. The TaNiSiC films remained X-ray amorphous after four hour-long annealings up to 700 °C, while TaNiC alloys with high Ni and C contents crystallized. These differences were attributed to a strong driving force for separation of Ni and C in TaNiC, whereas the addition of Si, due to its solubility in the other elements, reduced the elemental segregation in TaNiSiC. The as-deposited TaNiSiC films exhibited hardnesses of 9–12 GPa. Annealing led to an increase in hardness by 2–4 GPa, due to decreases in average atomic distance, as evidenced by X-ray diffraction measurements. Potentiodynamic polarizations from –0.7 to +1.5 V vs. Ag/AgCl (3 M NaCl) in 10 mM sodium borate showed lower current densities by up to 2 orders of magnitude with increasing Ta content (28–52 at.%). Changes in Si/C content (7–13 at.% Si) had no effect. However, optical microscopy showed that TaNiSiC films with high Si/low C contents (13/10 at.%) suffered much less localized etching compared to TaNiC films. Thus, Si had a significant role in increasing the mechanical strength, corrosion resistance, and thermal stability of the TaNiSiC films.

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  • 15.
    Kretschmer, Andreas
    et al.
    TU Wien, Inst Mat Sci & Technol, Getreidemarkt 9, A-1060 Vienna, Austria..
    Kirnbauer, Alexander
    TU Wien, Inst Mat Sci & Technol, Getreidemarkt 9, A-1060 Vienna, Austria..
    Pitthan, Eduardo
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Yalamanchili, Kumar
    Oerlikon Surface Solut AG, Iramalli 18, FL-9496 Balzers, Liechtenstein..
    Rudigier, Helmut
    Oerlikon Surface Solut AG, Iramalli 18, FL-9496 Balzers, Liechtenstein.;OC Oerlikon Management AG, CH-8808 Pfaffikon, SZ, Switzerland..
    Mayrhofer, Paul Heinz
    TU Wien, Inst Mat Sci & Technol, Getreidemarkt 9, A-1060 Vienna, Austria..
    High-entropy alloy inspired development of compositionally complex superhard (Hf,Ta,Ti,V,Zr)-B-N coatings2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 218, article id 110695Article in journal (Refereed)
    Abstract [en]

    Phase stability and mechanical properties of multimetal-boronnitride (Hf,Ta,Ti,V,Zr)-B-N is investigated by ab initio computations and experimental methods. (Hf,Ta,Ti,V,Zr)-B-N shows a strong energetic preference for the fcc NaCl-type structure over other structures up to a B:N ratio of 3.5. Reactively deposited (Hf,Ta,Ti,V,Zr)-B-N coatings show formation of X-ray amorphous BN, accompanied by a drastic hardness decrease with increasing B content. But non-reactively sputtered (Hf,Ta,Ti,V,Zr)-B-N coatings exhibit a single-phase fcc solid solution, up to the maximum B:N ratio of 1.12 studied, in good agreement with calculations. All non-reactively sputtered multimetal-boronnitride coatings contain a high Zr metal-fraction and approximate to 8at% C, stemming from impurities in the target. The single-phase coatings reach superhardness up to 46.3 GPa. Even after vacuum annealing to 1200 degrees C, the hardness of the coating with a B:N ratio of 1.03 is still 43.7 GPa, while that of ZrN0.72C0.28 decreased from 36.3 to 30.2 GPa. Our results demonstrate the importance of the deposition technique to deposit single-phased coatings with exceptional hardness and thermal stability. (C) 2022 The Authors. Published by Elsevier Ltd.

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  • 16.
    Lewin, Susanne
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Fleps, Ingmar
    ETH Zurich.
    Åberg, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Ferguson, Stephen J.
    ETH Zurich.
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Öhman-Mägi, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Helgason, Benedikt
    ETH Zurich.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Additively manufactured mesh-type titanium structures for cranial implants: E-PBF vs. L-PBF2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 197, article id 109207Article in journal (Refereed)
    Abstract [en]

    A patient-specific titanium-reinforced calcium phosphate (CaP–Ti) cranial implant has recently shown promising clinical results. Currently, its mesh-type titanium structure is additively manufactured using laser beam powder bed fusion (L-PBF). Nevertheless, an electron-beam (E-PBF) process could potentially be more time efficient. This study aimed to compare the geometrical accuracy and mechanical response of thin titanium structures manufactured by L-PBF (HIPed) and E-PBF (as-printed). Tensile test (ø = 1.2 mm) and implant specimens were manufactured. Measurements by μCT revealed a deviation in cross-sectional area as compared to the designed geometry: 13–35% for E-PBF and below 2% for L-PBF. A superior mechanical strength was obtained for the L-PBF specimens, both in the tensile test and the implant compression tests. The global peak load in the implant test was 457 ± 9 N and 846 ± 40 N for E-PBF and L-PBF, respectively. Numerical simulations demonstrated that geometrical deviation was the main factor in implant performance and enabled quantification of this effect: 34–39% reduction in initial peak force based on geometry, and only 11–16% reduction based on the material input. In summary, the study reveals an uncertainty in accuracy when structures of sizes relevant to mesh-type cranial implants are printed by the E-PBF method.

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  • 17.
    Li, Xiaojie
    et al.
    Dalian Univ Technol, Minist Educ, Key Lab Mat Modificat Laser Electron & Ion Beams, Dalian 116024, Peoples R China.;KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Li, Xiaoqing
    KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Schonecker, Stephan
    KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Li, Ruihuan
    Changzhou Vocat Inst Mechatron Technol, Inst Mold Technol, Changzhou 213164, Peoples R China..
    Zhao, Jijun
    Dalian Univ Technol, Minist Educ, Key Lab Mat Modificat Laser Electron & Ion Beams, Dalian 116024, Peoples R China..
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.;Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    Understanding the mechanical properties of reduced activation steels2018In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 146, p. 260-272Article in journal (Refereed)
    Abstract [en]

    Reduced activation ferritic/martensitic (RAFM) steels are structural materials with potential application in Generation-IV fission and fusion reactors. We use density-functional theory to scrutinize the micro-mechanical properties of the main alloy phases of three RAFM steels based on the body-centered cubic FeCrWVMn solid solution. We assess the lattice parameters and elastic properties of ferromagnetic alpha-Fe and Fe91Cr9, which are the main building blocks of the RAFM steels, and present a detailed analysis of the calculated alloying effects of V, Cr, Mn, and W on the mechanical properties of Fe91Cr9. The composition dependence of the elastic parameters is decomposed into electronic and volumetric contributions and studied for alloying levels that cover the typical intervals in RAFM steels. A linear superposition of the individual solute effects on the properties of Fe91Cr9 is shown to provide an excellent approximation for the ab initio values obtained for the RAFM steels. The intrinsic ductility is evaluated through Rice's phenomenological theory using the surface and unstable stacking fault energies, and the predictions are contrasted with those obtained by empirical criteria. Alloying with V or W is found to enhance the ductility, whereas additional Cr or Mn turns the RAFM base alloys more brittle.

  • 18.
    Li, Xiaojie
    et al.
    Taizhou Univ, Dept Phys, Taizhou 318000, Peoples R China.;KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Schönecker, Stephan
    KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Li, Xiaoqing
    KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden..
    Zhao, Jijun
    Dalian Univ Technol, Key Lab Mat Modificat Laser Electron & Ion Beams, Minist Educ, Dalian 116024, Peoples R China..
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. KTH Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.;Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    The influence of temperature on the elastic properties of body-centered cubic reduced activation steels2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 197, article id 109282Article in journal (Refereed)
    Abstract [en]

    A first-principles based modeling approach to the effect of temperature on the isothermal single-crystal and polycrystalline elastic parameters of Fe-rich solid solutions is reported. The approach integrates alloy theory for chemical and magnetic disorders with accessible experimental data for the equilibrium volume and ferromagnetic phase transition, and is adopted to predict the temperature-dependent elastic parameters of the body-centered cubic phase of three reduced activation steels, CLAM/CLF-1, F82H, EUROFER97, considered as high-temperature material in power reactors. The predictions are assessed based on available experimental data for a reduced activation steel and both experimental and theoretical data for pure Fe. Alloying effects on the elastic constants relative to pure Fe are found to differ in the magnetically ordered and disordered phases. Contributions due to loss of long-range magnetic order, volume expansion, and entropy are important in determining the temperature dependence of the elastic parameters in all investigated materials. A previously reported, peculiar magneto-volume phenomenon on the equation of state in pure Fe is gradually removed by alloying and magnetic disordering, which requires particular attention when describing the thermo-chemical effects derived from the equation of state in Fe-rich solid solutions.

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  • 19.
    Liu, Dachuan
    et al.
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Dong, Li
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Wang, Huan
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Bai, Jianzhong
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Shi, Jiaxu
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Chen, Weicheng
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Yan, Hongji
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology. Karolinska Inst, AIMES Ctr Advancement Integrated Med & Engn Sci, S-17177 Stockholm, Sweden.;KTH Royal Inst Technol, S-17177 Stockholm, Sweden..
    Li, Bin
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Sun, Heng
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Chen, Song
    Soochow Univ, Affiliated Hosp 1, Suzhou Med Coll, Orthoped Inst,Dept Orthoped Surg,Sch Biol & Basic, Suzhou 215006, Jiangsu, Peoples R China..
    Amorphous iron-calcium phosphate-mediated biomineralized scaffolds for vascularized bone regeneration2023In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 235, article id 112413Article in journal (Refereed)
    Abstract [en]

    Construction of organic-inorganic composites similar to natural bone in terms of structure and composition has attracted extensive attention. However, the clinical applications of these composites are limited due to the insufficient osteogenic and mechanical properties. In nature, the presence of amorphous iron-calcium phosphate (Fe-ACP) strengthens the mechanical properties of some biominerals, and our previous study has revealed its synthetic route and in vitro osteogenic properties. However, the potential role of Fe-ACP on biomineralization and constructing biomimetic scaffolds for bone regeneration has not been studied. Herein, a biomimetic scaffold with good osteogenic property was fabricated based on the mineralization of Fe-ACP, with the assistance of ice-templated freeze-casting. The in vitro study showed that the mineralized scaffolds possessed favorable biocompatibility and osteogenic property. Moreover, the scaffolds promoted cell chemotaxis and angiogenic property by upregulating the hypoxia inducible factor-1 alpha (HIF-1 alpha). In vivo experiment demonstrated potent early osteogenesis along with angiogenesis and ultimately promoted bone regeneration. Overall, the mineralized scaffold mediated by Fe-ACP precursors provide a unique platform to enhance bone tissue repair.

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  • 20.
    Malinovskis, Paulius
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Fritze, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Riekehr, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    von Fieandt, Linus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Cedervall, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Rehnlund, David
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Synthesis and characterization of multicomponent (CrNbTaTiW)C films for increased hardness and corrosion resistance2018In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 149, p. 51-62Article in journal (Refereed)
    Abstract [en]

    Multicomponent carbide thin films of (CrNbTaTiW)C (30–40 at.% C) with different metal contents were depos-ited at different temperatures using non-reactive DC magnetron sputtering. The lattice distortion for the metallattice was estimated to vary from about 3 to 5%. Most films crystallized in the cubic B1 structure but Ta/W-rich films deposited at 600 °C exhibited a tetra gonal distortion. X-ray diffraction results sh ow that near-equimolar films exhibited a strong (111) texture. In contrast, Ta/W-rich films exhibited a shift from (111) to(100) texture at 450 °C. The in-plane relationship was determined to MC(111)[-12-1]//Al2O3(001)[110] with alattice mismatch of about 11% along the Al2O3[110] direction. A segregation of Cr to the grain boundaries was ob-served in all films. The microstructure was found to be the most important factor for high hardness. Less denseNb-rich and near-equimolar films deposited at low tem peratures exhib ited the low est hardnes s (12 GPa),while very dense Ta/W-rich high temperature films were found to be the hardest (36 GPa). No correlation wasfound between the lattice distortion and the hardness. Corrosion studies revealed that the multicomponentfilms exhibited excellent corrosion resistance, superior to that of a reference hyper-duplex stainless steel, in1.0 M HCl.

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  • 21.
    Malmelöv, Andreas
    et al.
    Luleå Univ Technol, Mech Solid Mat, SE-97187 Luleå, Sweden..
    Hassila, Carl Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Fisk, Martin
    Malmö Univ, Mat Sci & Appl Math, SE-20506 Malmö, Sweden.;Lund Univ, Div Solid Mech, POB 118, SE-22100 Lund, Sweden..
    Wiklund, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Lundbäck, Andreas
    Luleå Univ Technol, Mech Solid Mat, SE-97187 Luleå, Sweden..
    Numerical modeling and synchrotron diffraction measurements of residual stresses in laser powder bed fusion manufactured alloy 6252022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 216, article id 110548Article in journal (Refereed)
    Abstract [en]

    Residual stresses in metal additive manufactured components are a well-known problem. It causes dis-tortion of the samples when removing them from the build plate, as well as acting detrimental with regard to fatigue. The understanding of how residual stresses in a printed sample are affected by process parameters is crucial to allow manufacturers to tune their process parameters, or the design of their com-ponent, to limit the negative influence of residual stresses. In this paper, residual stresses in additive manufactured samples are simulated using a thermo-mechanical finite element model. The elasto-plastic behavior of the material is described by a mechanism-based material model that accounts for microstructural and relaxation effects. The heat source in the finite element model is calibrated by fitting the model to experimental data. The residual stress field from the finite element model is compared with experimental results attained from synchrotron X-ray diffraction measurements. The results from the model and measurement give the same trend in the residual stress field. In addition, it is shown that there is no significant difference in trend and magnitude of the resulting residual stresses for an alterna-tion in laser power and scanning speed.

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  • 22.
    Mao, Fang
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyberg, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thersleff, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Andersson, Anna
    ABB AB, Corp Res, Insulat & Mat Technol, SE-72178 Vasteras, Sweden..
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Combinatorial magnetron sputtering of AgFeO2 thin films with the delafossite structure2016In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 91, p. 132-142Article in journal (Refereed)
    Abstract [en]

    The main objective of this study is to demonstrate the strength of the combinatorial approach to rapidly and effectively identify suitable process parameters for the synthesis of AgFeO2 filmswith layered delafossite structure. (00l)- textured delafossite AgFeO2 thin films have been successfully deposited for the first time without post-annealing by magnetron sputtering from elemental silver and iron targets in a reactive Ar-O-2 atmosphere. Gradient filmswith a wide composition range were deposited on singlewafers and subsequent screenings of phase- and chemical compositions were employed to optimize process parameters. The optimum deposition temperature for single-phase AgFeO2 growth was 450 degrees C using a Ag target powered at 15 W with a pulsing frequency of 150 kHz and a Fe target powered at constant 120 W at a total pressure of 4 mTorr and a O-2 partial pressure of 0.8 mTorr. Selected films were studied with scanning electron microcopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The optical band gap for the indirect transition in the AgFeO2 film was determined to 1.7 +/- 0.1 eV, and the band gap for the direct transition was 2.5 +/- 0.1 eV. The film showed insulating electrical properties.

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  • 23.
    Marattukalam, Jithin James
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Karlsson, Dennis
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pacheco, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Beran, Přemysl
    Department of Neutron Physics, Nuclear Physics Institute, ASCR, CZ -25068 Řež, Czech Republic; European Spallation Source ERIC, Box 176, 22100 Lund, Sweden.
    Wiklund, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Hjörvarsson, Björgvin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    The effect of laser scanning strategies on texture, mechanical properties, and site-specific grain orientation in selective laser melted 316L SS2020In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 193, article id 108852Article in journal (Refereed)
    Abstract [en]

    Selective laser melting has been used to demonstrate the striking effect of laser scanning strategies on the crystalline texture in 316L SS. The aligned crystal orientation along the tensile direction (Z-axis) could be varied using the scanning strategy. A strong 〈100〉 single crystalline-like texture is obtained in the direction of the laser scan and a 〈110〉 texture was observed in the build direction when using a bidirectional scan without rotation. Fiber texture was observed along the tensile direction when the bi-directional laser scanning vectors were rotated by 67° (Rot-scan) for each layer. The study highlights a correlation between laser scanning strategies with resulting textures, microstructure, and mechanical properties in as-printed bulk 316L SS. The hardness, Young's modulus, and ultimate tensile strength were significantly influenced by the final microstructure, crystallographic texture, and porosity. Furthermore, the applied laser scanning strategies made it possible to tailor crystallographic textures locally within the component. This was demonstrated by printing characters with a fiber texture, in a matrix with ⟨100⟩ texture parallel to the Z-axis.

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  • 24.
    Molavitabrizi, Danial
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Suzuki, Asuka
    Department of Materials Process Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
    Kobashi, Makoto
    Department of Materials Process Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
    Mousavi, S. Mahmoud
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Mechanical coupling and tuned anisotropic elasticity: Numerical and experimental material design for shear-normal and shear-shear interactions2023In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 230, article id 111950Article in journal (Refereed)
    Abstract [en]

    Mechanical coupling in architectured materials has been traditionally investigated in the context of generalized continuum mechanics and is often assumed to be non-existent in the framework of classical continuum mechanics. In this paper, we challenge this misconception and study an anisotropic architectured material exhibiting shear-shear and shear-normal coupling from the standpoint of classical continuum mechanics. The material is non-regular tetrahedron lattice, a potential candidate for biomedical implants, but the lack of understanding about its anisotropic behavior and mechanical couplings has limited its application. We exploited the unit-cell definition with periodic boundary conditions and performed elastic and elastoplastic homogenizations. Non-zero coupling sub-matrices appeared in the homogenized elasticity matrix, which we further transformed into material’s natural coordinate system using elastic distance function. This allowed for anisotropy identification and determination of all the coupling parameters. Next, compression tests are conducted on laser powder bed fused Al-12Si (mass%) lattice samples with different relative densities and spatial orientations. Employing test data, mechanical anisotropy and shear-normal couplings are experimentally characterized. Both numerical and experimental results confirmed the presence of mechanical couplings and predicted a similar anisotropic tendency in the material. Finally, the role of manufacturing defects in deterioration of as-designed mechanical properties is discussed.

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  • 25. Mukhamedov, B.O.
    et al.
    Fritze, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Ottosson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Osinger, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Alling, B.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Abrikosov, I.A.
    Tetragonal distortion in magnetron sputtered bcc-W films with supersaturated carbon2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 214, article id 110422Article in journal (Refereed)
    Abstract [en]

    Carbon has a low solid solubility in bcc tungsten at equilibrium. However, metastable supersaturated solid solutions can be synthesized with magnetron sputtering. Here, we present a systematic study on the phase stability and mechanical properties of such supersaturated W–C solid solutions. Θ–2θ scans show a split of the 200/020 and the 002 peaks for supersaturated films which is explained by a tetragonal distortion of the bcc structure. This split increases with increasing C content and is maximized at 4 at.% C, where we observe an a/b axis of 3.15–3.16 Å and a c-axis of 3.21–3.22 Å. We performed first-principles calculations of lattice parameters, mixing enthalpies, elastic constants and polycrystalline elastic moduli for cubic and tetragonal W–C solid solutions. Calculations show that tetragonal structure is more stable than the bcc supersaturated solid solution and the calculated lattice parameters and Young’s moduli follow the same trends as the experimental ones as a function of C concentration. The results suggest that supersaturated films with lattice distortion can be used as a design approach to improve the properties of transition metal films with a bcc structure.

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  • 26. Oji, U.K.
    et al.
    Pacheco, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Backs, A.
    Woracek, R.
    Pooley, D. E.
    Nilsen, G. J.
    Nemkovski, K.
    Kockelmann, W.
    Tremsin, A. S.
    Hilger, A.
    Ziesche, R.
    Manke, I.
    Cubitt, R.
    Kardjilov, N.
    Implementation of time of flight polarized neutron imaging at IMAT-ISIS2023In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 235, article id 112429Article in journal (Refereed)
    Abstract [en]

    In this study, we report the first case of design and implementation of a polarized neutron imaging option on the Imaging and Materials Science & Engineering Station (IMAT). This is a significant addition to the capabilities of the station that allows the characterization of advanced magnetic materials for different engineering applications. Combining its time-of-flight feature with a polarized beam yields data that facilitate both quantitative and qualitative analysis of magnetic materials. Using the simple field of an aluminium solenoid, we perform a characterization of the new setup. In addition, we present polarized measurements of additively manufactured (AM) MnAl samples where the magnetic anisotropy due to the fabrication process has been investigated as a first scientific application of the setup. The results indicate that the anisotropy of the material can be engineered through variation of the AM fabrication parameters.

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  • 27.
    Osinger, Barbara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Mao, Huahai
    KTH Royal Inst Technol, Stockholm, Sweden.;Thermo Calc Software AB, Solna, Sweden..
    Fritze, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Riekehr, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Investigation of the phase formation in magnetron sputtered hard multicomponent (HfNbTiVZr)C coatings2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 221, article id 111002Article in journal (Refereed)
    Abstract [en]

    Multicomponent carbides have gained interest especially for ultra-high temperature applications, due to their ceramic hardness, good oxidation resistance and enhanced strength. In this study the phase forma-tion, stability and mechanical properties of (HfNbTiVZr)C multicomponent carbide coatings were inves-tigated. Phase stability was predicted by the CALPHAD (CALculation of PHAse Diagrams) methods. This revealed that the multicomponent solid solution phase is only stable at elevated temperatures, namely above 2400 degrees C. At lower temperatures a phase mixture was predicted, with a particular tendency for V to segregate. Magnetron sputtered thin films deposited at 300 degrees C exhibited a single NaCl-type multicom-ponent carbide phase, which attributes to the kinetic stabilisation of simple structures during thin film growth. Films deposited at 700 degrees C, or exposed to UHV annealing at 1000 degrees C, however, revealed the decom-position of the single-phase multicomponent carbide by partial elemental segregation and formation of additional phases. Thus, confirming the CALPHAD predictions. These results underscore the importance of explicitly considering temperature when discussing the stability of multicomponent carbide materials, as well as the applicability of CALPHAD methods for predicting phase formation and driving forces in these materials. The latter being crucial for designing materials, such as carbides, that are used in appli-cations at elevated temperatures.

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  • 28.
    Porenta, Nikolaus
    et al.
    Swiss Fed Inst Technol, Dept Mat, Lab Nanomet, Vladimir Prelog Weg 1-5-10, CH-8093 Zurich, Switzerland..
    Nydegger, Mirco
    Swiss Fed Inst Technol, Dept Mat, Lab Nanomet, Vladimir Prelog Weg 1-5-10, CH-8093 Zurich, Switzerland..
    Menetrey, Maxence
    Swiss Fed Inst Technol, Dept Mat, Lab Nanomet, Vladimir Prelog Weg 1-5-10, CH-8093 Zurich, Switzerland..
    Hammadi, Souzan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Swiss Fed Inst Technol, Dept Mat, Lab Nanomet, Vladimir Prelog Weg 1-5-10, CH-8093 Zurich, Switzerland..
    Reiser, Alain
    Swiss Fed Inst Technol, Dept Mat, Lab Nanomet, Vladimir Prelog Weg 1-5-10, CH-8093 Zurich, Switzerland.;MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA..
    Spolenak, Ralph
    Swiss Fed Inst Technol, Dept Mat, Lab Nanomet, Vladimir Prelog Weg 1-5-10, CH-8093 Zurich, Switzerland..
    Micron-scale additive manufacturing of binary and ternary alloys by electrohydrodynamic redox 3D printing2023In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 234, article id 112364Article in journal (Refereed)
    Abstract [en]

    Across disciplines and length scales, alloying of metals is a common and necessary strategy to optimise materials performance. While the manufacturing of alloys in bulk and thin film form is well understood, the fabrication of alloyed 3D nanostructures with precise control over the composition remains a challenge. Herein, we demonstrate that electrohydrodynamic redox 3D printing from mixed metal salt solutions is a versatile approach for the 3D nanofabrication of alloys. We propose that the droplet-by-droplet nature of the electrohydrodynamic redox printing process allows straightforward electroplating of alloys with composition solely controlled by the composition of the electrolyte solution, independent of the reduction potential of the involved cations. As a demonstration of the direct control of composition, we deposit binary and ternary alloys of Ag, Cu and Zn. TEM microstructure analysis indicates homogeneous alloying at the nanoscale and the formation of a metastable solid-solution phase for Ag-Cu and a two phase system for Ag-Cu-Zn alloys. The straightforward approach to alloying with an electrochemical technique promises novel opportunities for optimisation of properties of 3D nanofabricated metals.

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  • 29.
    Schonecker, Stephan
    et al.
    KTH Royal Inst Technol, Dept Mat Sci & Engn, Unit Properties, SE-10044 Stockholm, Sweden..
    Li, Xiaojie
    Taizhou Univ, Dept Phys, Taizhou 318000, Zhejiang, Peoples R China..
    Wei, Daixiu
    Tohoku Univ, Inst Mat Res, 2-1-1 Katahira, Sendai, Miyagi 9808577, Japan..
    Nozaki, Shogo
    Tohoku Univ, Dept Mat Sci, 6-6-02 Aramaki Aza Aoba, Sendai, Miyagi 9808579, Japan..
    Kato, Hidemi
    Tohoku Univ, Inst Mat Res, 2-1-1 Katahira, Sendai, Miyagi 9808577, Japan..
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. KTH Royal Inst Technol, Dept Mat Sci & Engn, Unit Properties, SE-10044 Stockholm, Sweden.;Wigner Res Ctr Phys, Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    Li, Xiaoqing
    KTH Royal Inst Technol, Dept Mat Sci & Engn, Unit Properties, SE-10044 Stockholm, Sweden..
    Harnessing elastic anisotropy to achieve low-modulus refractory high-entropy alloys for biomedical applications2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 215, article id 110430Article in journal (Refereed)
    Abstract [en]

    A high-priority target in the design of new metallic materials for load-bearing implant applications is the reduction of Young's modulus approximating that of cortical bone in the predominant loading direction. Here, we explore how directionally preferential bulk elastic properties of implant materials are achieved by harnessing elastic anisotropy. Specifically focusing on recently proposed biocompatible refractory high-entropy alloys (RHEAs) in the body-centered cubic structure, we conduct systematic densityfunctional theory calculations to investigate the single-crystal elastic properties of 21 Ti-containing RHEAs. Our results provide evidence that the valence electron count has a dominant influence on elastic anisotropy and crystal directions of low Young's modulus and high torsion modulus in the RHEAs. By means of modeling the orientation distribution function for crystallographic texture, we examine the effect of non-random texture on the anisotropic poly-crystalline Young's modulus and torsion modulus with varying texture sharpness. We adopt fiber textures that can result from rolling and distinct texture orientations that can form during rapid directional solidification. We discuss the potential for lowering Young's modulus in the RHEAs by using single crystals or textured aggregates. Furthermore, we prepare four of the theoretically considered alloys by arc-melting and report their lattice parameters, quasi isotropic Young's moduli, and Wickers hardnesses. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

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  • 30.
    Sun, Xun
    et al.
    Xi An Jiao Tong Univ, Frontier Inst Sci & Technol, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China.;Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Lu, Song
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Xie, Ruiwen
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    An, Xianghai
    Univ Sydney, Sch Aerosp Mech & Mechatron Engn, Sydney, NSW 2006, Australia.
    Li, Wei
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.
    Zhang, Tianlong
    Xi An Jiao Tong Univ, Frontier Inst Sci & Technol, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China.
    Liang, Chuanxin
    Xi An Jiao Tong Univ, Frontier Inst Sci & Technol, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China.
    Ding, Xiangdong
    Xi An Jiao Tong Univ, Frontier Inst Sci & Technol, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China.
    Wang, Yunzhi
    Ohio State Univ, Dept Mat Sci & Engn, 2041 Coll Rd, Columbus, OH 43210 USA.
    Zhang, Hualei
    Xi An Jiao Tong Univ, Frontier Inst Sci & Technol, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China.
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden; Wigner Res Ctr Phys, Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary.
    Can experiment determine the stacking fault energy of metastable alloys?2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 199, article id 109396Article in journal (Refereed)
    Abstract [en]

    Stacking fault energy (SFE) plays an important role in deformation mechanisms and mechanical properties of face-centered cubic (fcc) metals and alloys. In many concentrated fcc alloys, the SFEs determined from density functional theory (DFT) calculations and experimental methods are found having opposite signs. Here, we show that the negative SFE by DFT reflects the thermodynamic instability of the fcc phase relative to the hexagonal close-packed one; while the experimentally determined SFEs are restricted to be positive by the models behind the indirect measurements. We argue that the common models underlying the experimental measurements of SFE fail in metastable alloys. In various concentrated solid solutions, we demonstrate that the SFEs obtained by DFT calculations correlate well with the primary deformation mechanisms observed experimentally, showing a better resolution than the experimentally measured SFEs. Furthermore, we believe that the negative SFE is important for understanding the abnormal behaviors of partial dislocations in metastable alloys under deformation. The present work advances the fundamental understanding of SFE and its relation to plastic deformations, and sheds light on future alloy design by physical metallurgy.

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  • 31.
    Thersleff, Thomas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Giraldo, Sergio
    Catalonia Inst Energy Res IREC, Barcelona 08930, Spain..
    Neuschitzer, Markus
    Catalonia Inst Energy Res IREC, Barcelona 08930, Spain..
    Pistor, Paul
    Catalonia Inst Energy Res IREC, Barcelona 08930, Spain..
    Saucedo, Edgardo
    Catalonia Inst Energy Res IREC, Barcelona 08930, Spain..
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Chemically and morphologically distinct grain boundaries in Ge-doped Cu2ZnSnSe4 solar cells revealed with STEM-EELS2017In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 122, p. 102-109Article in journal (Refereed)
    Abstract [en]

    Critical to the future development of Cu2ZnSnSe4 (CZTSe) materials is a comprehensive understanding of the underlying nanoscale mechanisms responsible for reduced performance. Investigating these mechanisms is challenging since they arise on the nanoscale, yet manifest themselves over macroscopic regions. Here, we present an analytical study combining Scanning Transmission Electron Microscopy (STEM), sample preparation, and hyperspectral Electron Energy Loss Spectroscopy (EELS) mapping techniques to meet this challenge. We apply our method to a Ge-doped CZTSe sample with a measured efficiency of 10.1%, revealing that its microstructure is dominated by two distinct types of grain boundaries. The first type appears in the upper half of the absorber separating large grains. These are Cu-enriched, Se-poor, and have varying amounts of . The second type of grain boundary is largely parallel to the substrate and appears predominately in the lower half of the absorber where the Cu/Zn ratio of the kesterite material is slightly lower. These grain boundaries contain voids and Sn oxide nanoparticles, exhibit high concentrations of Na, Cd, and S, and Cu assumes a higher valence state. We conclude with a discussion on the nature of and possible technological implications of these grain boundaries in this system.

  • 32.
    Tian, Li-Yun
    et al.
    Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.;Dalian Univ Technol, Key Lab Mat Modificat Laser Ion & Electron Beams, Minist Educ, Dalian 116024, Peoples R China..
    Wang, Guisheng
    Beijing Univ Technol, Sch Appl Math & Phys, Beijing, Peoples R China..
    Harris, Joshua S.
    North Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA..
    Irving, Douglas L.
    North Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA..
    Zhao, Jijun
    Dalian Univ Technol, Key Lab Mat Modificat Laser Ion & Electron Beams, Minist Educ, Dalian 116024, Peoples R China..
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden.;Wigner Res Ctr Phys, Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    Alloying effect on the elastic properties of refractory high-entropy alloys2017In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 114, p. 243-252Article in journal (Refereed)
    Abstract [en]

    Ab initio total energy calculations are used to determine the elastic properties of TiZrVNb, TiZrNbMo and TiZrVNbMo high-entropy alloys in the body centered cubic (bcc) crystallographic phase. Calculations are performed using the Vienna Ab initio Simulation Package and the Exact Muffin-Tin Orbitals methods, and the compositional disorder is treated within the frameworks of the special quasi-random structures technique and the coherent potential approximation, respectively. Special emphasis is given to the effect of local lattice distortion and trends against composition. Significant distortion can be observed in the relaxed cells, which result in an overlap of the first and second nearest neighbor (NN) shells represented in the histograms. When going from the four-component alloys TiZrVNb and TiZrNbMo to the five-component TiZrVNbMo, the changes in the elastic parameters follow the expected trends, except that of C-44 which decreases upon adding equiatomic Mo to TiZrVNb despite of the large shear elastic constant of elemental Mo. Although the rule of mixtures turns out to be a useful tool to estimate the elastic properties of the present HEAs, to capture the more delicate alloying effects one needs to resort to ab initio results.

  • 33.
    Verma, Suresh K.
    et al.
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Nandi, Aditya
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Simnani, Faizan Zarreen
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Singh, Dibyangshee
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Sinha, Adrija
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Naser, Shaikh Sheeran
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Sahoo, Jyotirmayee
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Lenka, Sudakshya S.
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Panda, Pritam Kumar
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    Dutt, Ateet
    Univ Nacl Autonoma Mexico, Inst Invest Mat, Mexico City 04510, Mexico..
    Kaushik, Nagendra Kumar
    Kwangwoon Univ, Plasma Biosci Res Ctr, Dept Elect & Biol Phys, Seoul 01897, South Korea..
    Singh, Deobrat
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Suar, Mrutyunjay
    KIIT Univ, KIIT Sch Biotechnol, Bhubaneswar 751024, India..
    In silico nanotoxicology: The computational biology state of art for nanomaterial safety assessments2023In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 235, article id 112452Article in journal (Refereed)
    Abstract [en]

    In recent decade, nanotechnology has got an extensive advancement in terms of production and application of nanomaterials. With the advancement, concern has risen for their biomedical and ecological safety, provoking a detailed analysis of the safety assement. Numerous experimental and computational approach has been developed to accomplish the goal of safety assessment of nanomaterials leading to orgin of interdisciplinary fields like nanoinformatics. Nanoinformatics has accomplished significant strides with the development of several modeling frameworks, data platforms, knowledge infrastructures, and in silico tools for risk assessment forecasts of nanomaterials. This review is an attemption to decipher and establish the bridge between the two emerging scientific arenas that includes computational modeling and nanotoxicity. We have reviewed the recent informations to uncover the link between the computational toxicology and nanotoxicology in terms of biomedical and ecological applications. In addition to the details about nanomaterials interaction with the biological system, this article offers a concise evaluation of recent developments in the various nanoinformatics domains. In detail, the computational tools like molecular docking, QSAR, etc. for the prediction of nanotoxicity here have been described. Moreover, techniques like molecular dynamics simulations used for experimental data collection and their translation to standard computational formats are explored.

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  • 34.
    Wenyue, Zhao
    et al.
    Beihang Univ, Key Lab Aerosp Mat & Performance, Minist Educ, Sch Mat Sci & Engn, 37 Xueyuan Rd, Beijing 100191, Peoples R China.; Royal Inst Technol, Appl Mat Phys, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden.
    Wei, Li
    Royal Inst Technol, Appl Mat Phys, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden.
    Zhimei, Sun
    Beihang Univ, Key Lab Aerosp Mat & Performance, Minist Educ, Sch Mat Sci & Engn, 37 Xueyuan Rd, Beijing 100191, Peoples R China.
    Shengkai, Gong
    Beihang Univ, Key Lab Aerosp Mat & Performance, Minist Educ, Sch Mat Sci & Engn, 37 Xueyuan Rd, Beijing 100191, Peoples R China.
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Appl Mat Phys, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden.; Res Inst Solid State Phys & Opt, Wigner Res Ctr Phys, POB 49, H-1525 Budapest, Hungary .
    Tuning the plasticity of Ni-Mo solid solution in Ni-based superalloys by ab initio calculations2017In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 124, p. 100-107Article in journal (Refereed)
    Abstract [en]

    The generalized stacking fault energies of face centered cubic Ni-Mo solid solutions are calculated using the exact muffin-tin orbital method in combination with coherent potential approximation. The alloying of Mo in Ni is found to decrease the intrinsic stacking fault energy of the solid solution from 150 mJ/m(2) (pure Ni) to 50 mJ/m(2) (17.5 at.% Mo) almost linearly. At the same time, the unstable stacking fault energy (the unstable twin fault energy) of the Ni-based solid solution increases (decreases) in a small extent with increasing Mo concentration. Three different twinnability measures are adopted and all indicate a substantially enhanced twinning mechanism in Ni-Mo solid solutions with increasing concentration of Mo. The weaker Ni-Ni bonding at high Mo concentrations is considered to be the main mechanism behind the disclosed phenomena. Segregation of Mo to the fault plane is proved to have strong effect on the generalized stacking fault energy of Ni-based solid solution.

  • 35.
    Zendejas Medina, León
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tavares da Costa, Marcus V.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Paschalidou, E. Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindwall, Greta
    Royal Inst Technol KTH, Dept Mat Sci & Engn, Brinellvägen 23, SE-10044 Stockholm, Sweden.
    Riekehr, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Korvela, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Fritze, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Kolozsvári, Szilárd
    Plansee Composite Mat GmbH, Siebenburgerstr 23, DE-86983 Lechbruck, Germany.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Enhancing corrosion resistance, hardness, and crack resistance in magnetron sputtered high entropy CoCrFeMnNi coatings by adding carbon2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 205, article id 109711Article in journal (Refereed)
    Abstract [en]

    This study explores carbon addition as a materials design approach for simultaneously improving the hardness, crack resistance, and corrosion resistance of high entropy thin films. CoCrFeMnNi was selected as a starting point, due to its high concentration of weak carbide formers. The suppression of carbides is crucial to the approach, as carbide formation can decrease both ductility and corrosion resistance. Films with 0, 6, and 11 at.% C were deposited by magnetron co-sputtering, using a graphite target and a sintered compound target. The samples with 0 at.% C crystallized with a mixture of a cubic closed packed (ccp) phase and the intermetallic χ-phase. With 6 and 11 at.% C, the films were amorphous and homogenous down to the nm-scale. The hardness of the films increased from 8 GPa in the carbon-free film to 16 GPa in the film with 11 at.% C. Furthermore, the carbon significantly improved the crack resistance as shown in fragmentation tests, where the crack density was strongly reduced. The changes in mechanical properties were primarily attributed to the shift from crystalline to amorphous. Lastly, the carbon improved the corrosion resistance by a progressive lowering of the corrosion current and the passive current with increasing carbon concentration.

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  • 36.
    Zhang, Shang-Zhou
    et al.
    Yantai Univ, Sch Environm & Mat Engn, Qingquan Rd 30, Yantai 264005, Peoples R China..
    Cui, Hao
    Yantai Univ, Sch Environm & Mat Engn, Qingquan Rd 30, Yantai 264005, Peoples R China..
    Li, Ming-Man
    Yantai Univ, Sch Environm & Mat Engn, Qingquan Rd 30, Yantai 264005, Peoples R China.;Chinese Acad Sci, Inst Met Res, Wenhua Rd 72, Shenyang 110016, Peoples R China..
    Yu, Hui
    Chinese Acad Sci, Inst Met Res, Wenhua Rd 72, Shenyang 110016, Peoples R China.;Northeastern Univ, Sch Mat Sci & Engn, Wenhua Rd 3-11, Shenyang 110819, Peoples R China.;Shenyang Univ Technol, Sch Informat Sci & Engn, Shenliao West Rd 111, Shenyang 110870, Peoples R China..
    Vitos, Levente
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden.;Res Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary..
    Yang, Rui
    Chinese Acad Sci, Inst Met Res, Wenhua Rd 72, Shenyang 110016, Peoples R China..
    Hu, Qing-Miao
    Chinese Acad Sci, Inst Met Res, Wenhua Rd 72, Shenyang 110016, Peoples R China..
    First-principles study of phase stability and elastic properties of binary Ti-xTM (TM = V,Cr,Nb,Mo) and ternary Ti-15TH-yAl alloys2016In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 110, p. 80-89Article in journal (Refereed)
    Abstract [en]

    The phase stability and elastic property of binary Ti-chi TM (TM=V, Cr, Nb, Mo) and ternary Ti-15TH-yAl alloys are investigated systematically by using a first-principles method. The coherent potential approximation is employed to describe the random distribution of the alloying atoms in the alloys. We show that the transition metal (TM) elements V, Cr, Nb, Mo increase the elastic stability of the beta phase but decreases that of the a phase. The polycrystalline bulk modulus of the a phase increases with the concentration of the TM alloying elements whereas the Young's modulus and shear modulus are weakened. For the beta phase, all the polycrystalline elastic moduli hardens with the addition of the TM alloying elements. The influence of the simple metal (SM) element Al on the elastic properties is much weaker than the TM ones. The TM alloying elements increase the stability of the beta relative to the alpha and omega phases. Al stabilizes significantly the beta phase over the omega phase. Our calculations suggest that the d electron density dominates the elastic modulus but not the relative phase stability. The interaction between the TM and SM alloying elements in titanium alloys matters to the relative stability.

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