Microstructure and stress development in magnetron sputtered TiAlCr(N) films

TiAlCr(N) coatings were reactively magnetron-sputtered from a Ti-51Al-12Cr alloy target in this study by changing the nitrogen partial pressure over the range of 0–25% of the total pressure. The influence of nitrogen addition on the microstructure and stress development in the TiAlCr(N) films was investigated. With the increase of nitrogen partial pressure, the film microstructure undergoes a transition from amorphous-like metallic to crystalline nitride films. The crystalline phases are cubic Ti1−xAlxN and Cr1−xAlxN. The intrinsic stresses are compressive and become more so with nitrogen addition over most of the partial pressure range, while the stress–temperature curves during annealing vary significantly among the films. Nitrogen additions were found to increase the hardness of the films.