| AVS 57th International Symposium & Exhibition | |
| Advanced Surface Engineering | Tuesday Sessions |
| Session SE-TuM |
| Session: | Hard and Nanostructured Coatings |
| Presenter: | L.J.S. Johnson, Linköping University, Sweden |
| Authors: | L.J.S. Johnson, Linköping University, Sweden M. Thuvander, Chalmers University of Technology, Sweden K. Stiller, Chalmers University of Technology, Sweden M. Odén, Linköping University, Sweden L. Hultman, Linköping University, Sweden |
| Correspondent: | Click to Email |
The metastable solid solution of fcc-TiAlN is of interest both from an industrial perspective, since it is extensively used as a coating for cutting tools, and from a scientific perspective; as questions pertaining to the details of phase transformations in the system, not least spinodal decomposition, remain [1]. Here, the isostructural decomposition of Ti0.33Al0.67N thin films deposited by cathodic arc evaporation has been studied by atom probe tomography with close to atomic resolution. As-deposited films were found to deviate slightly from a random solid solution, and so be in the earliest stage of decomposition. After annealing at 900 °C for 2 h the films exhibited a spinodally decomposed nanostructure, in an intermediate stage. Results indicate that N segregates to the Al-rich domains in the annealed sample, causing the TiN-domains to be understoichiometric. Furthermore, a possible Kirkendall effect was detected in the annealed sample, with a modulation of the local stoichiometry by 1-2 at. % along the decomposition gradient. The implication of the findings for the age hardening of TiAlN alloy films will also be discussed.
[1] L. J. S. Johnson, Nanostructuring and Age Hardening in TiSiCN, ZrAlN, and TiAlN Thin Films, Licentitate Thesis no. 1442, Linköping University, 2010, http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56221