uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Norgren, Susanne
Alternative names
Publications (10 of 33) Show all publications
Fowler, L., Janson, O., Engqvist, H., Norgren, S. & Öhman, C. (2019). Antibacterial investigation of titanium-copper alloys using luminescent Staphylococcus epidermidis in a direct contact test. Materials science & engineering. C, biomimetic materials, sensors and systems, 97, 707-714
Open this publication in new window or tab >>Antibacterial investigation of titanium-copper alloys using luminescent Staphylococcus epidermidis in a direct contact test
Show others...
2019 (English)In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 97, p. 707-714Article in journal (Refereed) Published
Abstract [en]

Commercially pure titanium (CP-Ti), used as oral implants, is often populated by various bacterial colonies in the oral cavity. These bacteria can cause Peri-implantitis, leading to loss of bone tissue and failure of implants. With the increased awareness of antibiotic resistance, research has been directed towards alternative solutions and recent findings have indicated titanium-copper (Ti-Cu) alloys as a promising antibacterial material. The aim of this study was to produce homogeneous Ti-Cu alloys, with various concentrations of copper, and to characterise their antibacterial properties through direct contact tests, using luminescent bacteria, in addition to traditional materials characterisation techniques. Samples of CP-Ti and four different Ti-Cu alloys (1, 2.5, 3 and 10 wt%Cu) were produced in an arc-furnace, heated treated and rapidly quenched. X-ray diffraction revealed that Ti2Cu, was present only in the 10 wt%Cu alloy, however, scanning electron microscopy (SEM) indicated precipitates at the grain boundaries of the 3 wt%Cu alloy, which were confirmed to be of a copper rich phase by energy dispersive x-ray spectroscopy (EDS) analysis. EDS line scans confirmed that the alloys were homogenous. After 6 h, a trend between copper content and antibacterial rate could be observed, with the 10 wt%Cu alloy having the highest rate. SEM confirmed fewer bacteria on the 3 wt%Cu and especially the 10 wt%Cu samples. Although the 10 wt%Cu alloy gave the best antibacterial results, it is desired that the Cu concentration is below similar to 3 wt%Cu to maintain similar mechanical and corrosive performance as CP-Ti. Therefore, it is proposed that future work focuses on the 3 wt%Cu alloy.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2019
Keywords
Copper, Titanium, Antibacterial, S. epidermidis, Ti2Cu
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:uu:diva-378615 (URN)10.1016/j.msec.2018.12.050 (DOI)000457952800069 ()30678959 (PubMedID)
Available from: 2019-03-11 Created: 2019-03-11 Last updated: 2019-10-17Bibliographically approved
Heinrichs, J., Norgren, S., Jacobson, S. & Olsson, M. (2019). Cemented carbide wear initiation in sliding contact with iron ore. In: Proceedings of 2nd Sweden-China Symposium on Tribology: . Paper presented at 2nd Sweden-China Symposium on Tribology.
Open this publication in new window or tab >>Cemented carbide wear initiation in sliding contact with iron ore
2019 (English)In: Proceedings of 2nd Sweden-China Symposium on Tribology, 2019Conference paper, Oral presentation with published abstract (Other academic)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-392921 (URN)
Conference
2nd Sweden-China Symposium on Tribology
Available from: 2019-09-11 Created: 2019-09-11 Last updated: 2019-09-11
Toller-Nordström, L., Mingard, K. & Norgren, S. (2019). Deformation induced martensite in a Fe-Ni-Co binder phase of a hardmetal. Materials Characterization, 155, Article ID 109783.
Open this publication in new window or tab >>Deformation induced martensite in a Fe-Ni-Co binder phase of a hardmetal
2019 (English)In: Materials Characterization, ISSN 1044-5803, E-ISSN 1873-4189, Vol. 155, article id 109783Article in journal (Refereed) Published
Abstract [en]

This paper investigates deformation induced martensite in a hardmetal binder phase with target composition 50 wt% iron, 25 wt% nickel and 25 wt% cobalt. A fully austenitic ion polished cross-section surface was scratched with a diamond indenter and investigated with X-ray and electron diffraction. It was found that the top 100 nm of the scratched surface contained a mixture of austenite and a second phase identified as BCC/BCT martensite. The martensite grain size varied between a few 10 nm and a over 1 mu m in dimensions.

Keywords
Hardmetal, Deformation, Diffraction, Electron microscopy, Martensite
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:uu:diva-394261 (URN)10.1016/j.matchar.2019.06.025 (DOI)000483411900015 ()
Funder
Vinnova, Co-2014-01916
Available from: 2019-10-11 Created: 2019-10-11 Last updated: 2019-10-22Bibliographically approved
Fowler, L., Masia, N., Cornish, L. A., Chown, L. H., Engqvist, H., Norgren, S. & Öhman-Mägi, C. (2019). Development of Antibacterial Ti-Cu-x Alloys for Dental Applications: Effects of Ageing for Alloys with Up to 10 wt% Cu. Materials, 12(23), Article ID 4017.
Open this publication in new window or tab >>Development of Antibacterial Ti-Cu-x Alloys for Dental Applications: Effects of Ageing for Alloys with Up to 10 wt% Cu
Show others...
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 23, article id 4017Article in journal (Refereed) Published
Abstract [en]

Peri-implantitis, a disease caused by bacteria, affects dental implants in patients. It is widely treated with antibiotics, however, with growing antibiotic resistance new strategies are required. Titanium-copper alloys are prospective antibacterial biomaterials, with the potential to be a remedy against peri-implantitis and antibiotic resistance. The aim of this study was to investigate Ti-Cux alloys, exploring how Cu content (up to 10 wt%) and ageing affect the material properties. Electron microscopy, X-ray diffraction, hardness testing, bacteriological culture, and electrochemical testing were employed to characterize the materials. It was found that alloys with above 3 wt% Cu had two phases and ageing increased the volume fraction of Ti2Cu. An un-aged alloy of 5 wt% Cu showed what could be Ti3Cu, in addition to the α-Ti phase. The hardness gradually increased with increased Cu additions, while ageing only affected the alloy with 10 wt% Cu (due to changes in microstructure). Ageing resulted in faster passivation of the alloys. After two hours the aged 10 wt% Cu alloy was the only material with an antibacterial effect, while after six hours, bacteria killing occurred in all alloys with above 5 wt% Cu. In conclusion, it was possible to tune the material and antibacterial properties of Ti-Cux alloys by changing the Cu concentration and ageing, which makes further optimization towards an antibacterial material promising.

Place, publisher, year, edition, pages
Switzerland: MDPI, 2019
Keywords
titanium alloys, copper, Ti2Cu, Ti3Cu, biomaterial, antibacterial
National Category
Medical Materials
Identifiers
urn:nbn:se:uu:diva-395300 (URN)10.3390/ma12234017 (DOI)000510178700213 ()31816905 (PubMedID)
Funder
The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), SA2017-7127
Available from: 2019-10-16 Created: 2019-10-16 Last updated: 2020-03-11Bibliographically approved
Haglöf, F., Kaplan, B., Norgren, S., Blomqvist, A. & Selleby, M. (2019). Experimental study of carbides in the Ti-Cr-C system. Journal of Materials Science, 54(19), 12358-12370
Open this publication in new window or tab >>Experimental study of carbides in the Ti-Cr-C system
Show others...
2019 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 54, no 19, p. 12358-12370Article in journal (Refereed) Published
Abstract [en]

The Ti-Cr-C system has been studied by producing samples within the MC-M3C2-M7C3 (M=Ti, Cr) and MC-M3C2-graphite equilibria. The main purpose was to determine the solubility of Cr in MC; however, the solubility of Ti in M3C2 and M7C3 was also of interest, as well as the C content in MC. Heat treatments have been performed at 1673 and 1773 K for 300 h. Thereafter, the phase compositions have been measured with energy-dispersive X-ray spectroscopy (EDS) and wavelength-dispersive X-ray spectroscopy (WDS). X-ray diffraction (XRD), in combination with Rietveld refinement, has been used to determine the lattice parameter for MC. Density functional theory (DFT) calculations were performed to estimate the lattice parameter for MC as a function of composition, and the Rietveld refined lattice parameters for MC have then been recalculated to compositions in order to verify the EDS measurements. The results show that the EDS and XRD measurements give equal results. One conclusion is that, with the current conditions, 300 h is a sufficient heat treatment time in order to reach thermodynamic equilibrium. The other main conclusion is that the solubility of Cr in MC, in general, was overestimated by previous studies due to too short heat treatment times, but also that the solubility is very temperature dependent, especially for the MC-M3C2-graphite equilibrium. This clear temperature dependence was not taken into account in the existing thermodynamic description found in the literature.

Place, publisher, year, edition, pages
SPRINGER, 2019
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-390368 (URN)10.1007/s10853-019-03810-3 (DOI)000475764300007 ()
Funder
Swedish Foundation for Strategic Research , ID14-0076Vinnova
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Heinrichs, J., Norgren, S., Jacobson, S. & Olsson, M. (2019). Influence of cemented carbide binder type on wear initiation in rock drilling – investigated in sliding wear against magnetite rock. Paper presented at International Conference on the Science of Hard Materials, March 25-29, 2019, Khao Lak, Thailand. International journal of refractory metals & hard materials, 85, Article ID 105035.
Open this publication in new window or tab >>Influence of cemented carbide binder type on wear initiation in rock drilling – investigated in sliding wear against magnetite rock
2019 (English)In: International journal of refractory metals & hard materials, ISSN 0958-0611, E-ISSN 2213-3917, Vol. 85, article id 105035Article in journal (Refereed) Published
Abstract [en]

Cemented carbides, containing hard WC grains in a ductile Co binder, are commonly used as the rock crushing part of rock drills. They generally work well and show moderate and gradual wear in rock drilling applications. However, due to health issues, an alternative to Co is sought for, which will not compromise the performance. In the present work, the initiation of wear of cemented carbides with the two alternative binders Ni and Fe are investigated and compared to the common Co containing material in a sliding test. The sliding counterpart is magnetite, representing a rock type generally causing slow wear of the cemented carbides.

The results show that magnetite is immediately transferred to the cemented carbide thus forming thin layers, mainly on top of the binder, and WC grain fragments are removed. The chain of events is similar irrespective of binder, however the severity shows a strong dependence. The cemented carbide grade with the Ni binder shows relatively rapid wear initiation, compared to that with the Fe binder that shows moderate initiation and that with Co that is barely worn at all.

National Category
Other Materials Engineering
Identifiers
urn:nbn:se:uu:diva-392918 (URN)10.1016/j.ijrmhm.2019.105035 (DOI)000490047100020 ()
Conference
International Conference on the Science of Hard Materials, March 25-29, 2019, Khao Lak, Thailand
Funder
Knowledge Foundation, 20150193
Available from: 2019-09-11 Created: 2019-09-11 Last updated: 2020-02-24Bibliographically approved
Fowler, L., Van Vuuren, A. J., Goosen, W., Engqvist, H., Öhman-Mägi, C. & Norgren, S. (2019). Investigation of copper alloying in a TNTZ-Cux alloy. Materials, 12(22), Article ID 3691.
Open this publication in new window or tab >>Investigation of copper alloying in a TNTZ-Cux alloy
Show others...
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 22, article id 3691Article in journal (Refereed) Published
Abstract [en]

Alloying copper into pure titanium has recently allowed the development of antibacterial alloys. The alloying of biocompatible elements (Nb, Ta and Zr) into pure titanium has also achieved higher strengths for a new alloy of Ti-1.6 wt.% Nb-10 wt.% Ta-1.7 wt.% Zr (TNTZ), where strength was closer to Ti-6Al-4V and higher than grade 4 titanium. In the present study, as a first step towards development of a novel antibacterial material with higher strength, the existing TNTZ was alloyed with copper to investigate the resultant microstructural changes and properties. The initial design and modelling of the alloy system was performed using the calculation of phase diagrams (CALPHAD) methods, to predict the phase transformations in the alloy. Following predictions, the alloys were produced using arc melting with appropriate heat treatments. The alloys were characterized using energy dispersive X-ray spectroscopy in scanning transmission electron microscopy (STEM-EDS) with transmission Kikuchi diffraction (TKD). The manufactured alloys had a three-phased crystal structure that was found in the alloys with 3 wt.% Cu and higher, in line with the modelled alloy predictions. The phases included the α-Ti (HCP-Ti) with some Ta present in the crystal, Ti2Cu, and a bright phase with Ti, Cu and Ta in the crystal. The Ti2Cu crystals tended to precipitate in the grain boundaries of the α-Ti phase and bright phase. The hardness of the alloys increased with increased Cu addition, as did the presence of the Ti2Cu phase. Further studies to optimize the alloy could result in a suitable material for dental implants.

Place, publisher, year, edition, pages
Switzerland: MDPI, 2019
Keywords
Titanium alloy; microstructures; biomaterial, TNTZ
National Category
Medical Materials
Identifiers
urn:nbn:se:uu:diva-395278 (URN)10.3390/ma12223691 (DOI)000502284400048 ()31717395 (PubMedID)
Funder
The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), GA SA2017-7127
Available from: 2019-10-16 Created: 2019-10-16 Last updated: 2020-01-14Bibliographically approved
Yildiz, A. B., Weidow, J., Ryukhtin, V., Norgren, S., Wahnstrom, G. & Hedstrom, P. (2019). Very-small angle neutron scattering study on grain coarsening inhibition by V-doping of WC-Co composites. Scripta Materialia, 173, 106-109
Open this publication in new window or tab >>Very-small angle neutron scattering study on grain coarsening inhibition by V-doping of WC-Co composites
Show others...
2019 (English)In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 173, p. 106-109Article in journal (Refereed) Published
Abstract [en]

The mechanical properties of cemented carbides can be tuned by controlling WC grain coarsening and the simultaneous growth of the binder pocket size during the sintering. So far, bulk studies considering this phenomenon are scarce, but here, we report the first very-small angle neutron scattering (VSANS) study on cemented carbides. VSANS is supplemented with electron backscatter diffraction (EBSD) and the microstructural refinement by increasing V-doping (0, 0.02, 022, and 0.76 wt%) is quantified. The capability of VSANS as a non-destructive bulk probe for cemented carbides is shown, paving way for forthcoming in-situ studies.

Keywords
Small angle neutron scattering (SANS), Electron backscattering diffraction (EBSD), Cemented carbide, Grain growth, Grain refining
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-395778 (URN)10.1016/j.scriptamat.2019.08.005 (DOI)000487175400023 ()
Funder
Swedish Foundation for Strategic Research Swedish Foundation for Strategic Research
Available from: 2019-10-28 Created: 2019-10-28 Last updated: 2019-10-28Bibliographically approved
Meingast, A., Coronel, E., Blomqvist, A., Norgren, S., Wahnstrom, G. & Lattemann, M. (2018). High resolution STEM investigation of interface layers in cemented carbides. INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, 72, 135-140
Open this publication in new window or tab >>High resolution STEM investigation of interface layers in cemented carbides
Show others...
2018 (English)In: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, ISSN 0263-4368, Vol. 72, p. 135-140Article in journal (Refereed) Published
Abstract [en]

Cemented carbides with sub-micron grain size have increased the need to restrict grain growth during sintering. Commonly used inhibitors like V, Ti, and Cr have been observed to form interface layers in the interfaces between WC grains and the Co binder. Atomistic modeling has predicted the composition and thickness of the interface layers. Earlier, the interface layers have been characterized qualitatively using high resolution transmission electron microscopy (TEM). To get more information about the structure and composition of the interface layers in a Ti containing cemented carbide in this work, Z contrast imaging and spectroscopy using scanning transmission electron microscopy (STEM) have been combined. Elemental maps revealing the structure of the interface layers will be presented.

Keywords
STEM, SEM, EDXS, WC, Co, Ti
National Category
Materials Chemistry Ceramics
Identifiers
urn:nbn:se:uu:diva-387465 (URN)10.1016/j.ijrmhm.2017.12.028 (DOI)000427209100021 ()
Funder
Swedish Research Council, 2016-04342Swedish Foundation for Strategic Research , RMA 15-0062
Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2019-06-25Bibliographically approved
Kaplan, B., Odelros, S., Kritikos, M., Bejjani, R. & Norgren, S. (2018). Study of tool wear and chemical interaction during machining of Ti6Al4V. INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, 72, 253-256
Open this publication in new window or tab >>Study of tool wear and chemical interaction during machining of Ti6Al4V
Show others...
2018 (English)In: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, ISSN 0263-4368, Vol. 72, p. 253-256Article in journal (Refereed) Published
Abstract [en]

The present study concerns an investigation of the wear on three uncoated cemented carbide grades, with differing binder content and grain size, during longitudinal turning of Ti6Al4V as a function of cutting speed. The creater wear at end of tool life is studied in detail using electron microscopy and X-ray diffraction. It is observed that decreasing binder content results in slower wear progression and longer tool life. The microstructure of the adhered layer is also dependent on the binder content, where a lower amount of binder results in an increase of dark precipitates in the adhered layer. X-ray diffraction confirms the presence of bcc-W as a chemical wear product at the interface. Diffraction peaks corresponding to cubic (Ti,V)C are also occasionally observed.

Keywords
Ti6Al4V, Turning, Crater wear, Tungsten, X-ray diffraction
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:uu:diva-387466 (URN)10.1016/j.ijrmhm.2017.12.012 (DOI)000427209100036 ()
Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2019-06-25Bibliographically approved
Organisations

Search in DiVA

Show all publications