Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8023789 | Surface and Coatings Technology | 2018 | 32 Pages |
Abstract
The effect of a locally fluctuating [Ti]/[Al] ratio in the Ti1âxAlxN coatings on the formation of the lattice strains at the (Ti,Al)N/(Al,Ti)N interfaces and the influence of these interfaces on the stabilization of metastable (Al,Ti)N with face centered cubic structure were investigated using glancing angle X-ray diffraction, transmission electron microscopy and X-ray spectroscopy. A series of Ti1âxAlxN coatings with different [Ti]/[Al] ratios was deposited using cathodic arc evaporation from a titanium and an aluminum cathode. The overall chemical composition was controlled by the position of the respective sample in the deposition chamber and ranged from xâ¯=â¯[Al]/([Ti]â¯+â¯[Al])â¯=â¯0.06 to 0.64. The local fluctuations of the [Ti]/[Al] ratio were produced by interrupting the deposition from the titanium cathode. It was shown that such local fluctuations of the [Ti]/[Al] ratio generate large contrary residual stresses at the respective side of the (Ti,Al)N/(Al,Ti)N interface. These stresses were almost completely relieved after annealing at 750â¯Â°C. The stress relaxation after annealing was accompanied by an equalization of the [Ti]/[Al] ratio and by a decay of the composition fluctuations in the Ti1âxAlxN coatings. The stress relaxation and the reduction of the local composition gradients were concluded from measured residual stresses, stress-free lattice parameters and local concentration profiles.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
U. Ratayski, M. Motylenko, A. Ershova, M. Å Ãma, M. JÃlek, D. Rafaja,