Phase stability and initial low-temperature oxidation mechanism of Ti2AlC thin films
2013 (English)In: Journal of the European Ceramic Society, ISSN 0955-2219, Vol. 33, no 2, 375-382 p.Article in journal (Refereed) Published
Ti2AlC thin films deposited onto Al2O3 by magnetron sputtering were used as model for studying the early stages (andlt; 15 min) of relatively low-temperature (500 degrees C) oxidation of Ti2AlC. The well-defined microstructure of these films forms a surface of valleys, hillocks and plateaus comprised of basal-plane-oriented grains with a fraction of nonbasal-plane-oriented grains with out-of-plane orientation of (1 0 (1) over bar 3) and (1 0 (1) over bar 6) as shown by X-ray diffraction and s electron microscopy. During oxidation, Al2O3 clusters and areas of C-containing titania (TiOxCy) are formed on the surface. A mechanism is proposed in which the locations of the Al2O3 clusters are related to the migration of Al atoms diffusing out of Ti2AlC. The Al2O3 is initially formed in valleys or on plateaus where Al atoms have been trapped while TiOxCy forms by in-diffusion of oxygen into the Al-deficient Ti2AlC. At 500 degrees C, the migration of Al atoms is faster than the oxidation kinetics; explaining this microstructure-dependent oxidation mechanism.
Place, publisher, year, edition, pages
Elsevier , 2013. Vol. 33, no 2, 375-382 p.
Films, Electron microscopy, Carbides, Interfaces, Corrosion
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-87955DOI: 10.1016/j.jeurceramsoc.2012.09.003ISI: 000312687200021OAI: oai:DiVA.org:liu-87955DiVA: diva2:601040
Funding Agencies|Swedish National Graduate School in Materials Science||2013-01-282013-01-282016-08-31