Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8029161 | Surface and Coatings Technology | 2013 | 5 Pages |
Abstract
Anisotropy effects on the spinodal decomposition in cathodic arc evaporated cubic “phase c-Ti1âxAlxN coatings have been studied with respect to composition, microstructure and hardness properties before and after a continuous turning operation. Coatings are simultaneously being exposed to both a high temperature and high pressure during the metal cutting process. As evident from the current results, a high Al content coating, x = 0.66, when exposed to such extreme conditions decomposes into cubic c-AlN and c-TiN-rich domains. In this case, the evolving microstructure comprises interconnected spatially periodic, elongated and coherent cubic c-AlN and c-TiN-rich regions aligned along elastic compliant <100> crystal direction. A significantly different microstructure with randomly oriented domains is observed for a coating with an elemental composition closer to the isotropic limit, x = 0.28, exposed under the same conditions. From a coating hardness perspective, the nanoindentation results display a minor age hardening effect for the c-Ti1âxAlxN coating grown at x = 0.28 while the coating grown with x = 0.66 exhibits a significant age-hardening effect of about 18%. We conclude that both microstructure and age hardening behavior during spinodal decomposition of c-Ti1âxAlxN correlate to the relative amount of metal Ti/Al ratio and consequently to the elastic anisotropy of the as-grown coating material. These results provide new insights to the understanding of improved wear resistance of c-Ti1â xAlxN with Al content during metal cutting.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
M.P. Johansson Jõesaar, N. Norrby, J. Ullbrand, R. M'Saoubi, M. Odén,