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

Direct link
An analytical TEM study of (Ta,Al)C:C coatings in as-deposited and oxidised states
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
(English)Manuscript (Other (popular science, discussion, etc.))
URN: urn:nbn:se:uu:diva-92607OAI: oai:DiVA.org:uu-92607DiVA: diva2:165752
Available from: 2005-02-18 Created: 2005-02-18 Last updated: 2010-01-14Bibliographically approved
In thesis
1. Solving Problems in Surface Engineering and Tribology by Means of Analytical Electron Microscopy
Open this publication in new window or tab >>Solving Problems in Surface Engineering and Tribology by Means of Analytical Electron Microscopy
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

It is well known that thin coatings can provide increased lifetime and reduced energy consumption for tools and components. During use, e.g. in sliding contact, mechanical and chemical reactions often lead to the formation of new surface layers, tribofilms, possessing different properties compared to the original surface, hence affecting the overall performance. In this work, analytical electron microscopy was applied to investigate the structure and composition of tribofilms.

Concerning coatings, deposition parameter dependencies, stability and tribology were investigated. The carbon content of hydrogen-free TiCx coatings was shown to significantly influence the morphology. Low carbon content resulted in columnar grains with a strong texture while high carbon content led to the formation of randomly ordered TiCx crystals. The application of positive bias to the substrate as opposed to the normally used negative bias gave a fibrous structure of sputtered TiB2 and low residual stress with maintained hardness. Further, oxidation stability was examined on a (Ta,Al)C:C coating where oxidation led to partial oxidation and formation of AlTaO4 with an 8 nm interface.

A focused ion beam instrument was used to extract samples from certain areas of worn specimens. Tribological contact was observed to result in phase changes and intermixing of materials present in the contact. Sliding contact involving a Co-alloy led to a phase change from fcc to hcp. A 30 nm Co-rich tribofilm was observed with basal planes parallel to the surface. Fully formulated oil was found to inflict considerable wear to a metal doped carbon film through chemical reaction with the metal dopant. WC/Co cemented carbide used for rock drilling exhibited intermixing of rock and Co binder phase after field tests. Chemical vapour deposited diamond worn in nitrogen and argon showed formation of wear debris with amorphous structure containing nitrogen and graphitic like structure, respectively.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2005. 80 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 12
Materials science, Tribology, Electron Microscopy, Surface Engineering, Structure and Composition, Materialvetenskap
National Category
Materials Engineering
urn:nbn:se:uu:diva-4785 (URN)91-554-6148-4 (ISBN)
Public defence
2005-03-11, Siegbahnsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Available from: 2005-02-18 Created: 2005-02-18 Last updated: 2013-05-15Bibliographically approved

Open Access in DiVA

No full text

By organisation
Materials Science

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 220 hits
ReferencesLink to record
Permanent link

Direct link