Effect of si content in Ti–Al–Ta–Si–N coatings on their fracture under uniaxial tension

Effect of Si content on the patterns of deformation and fracture of Ti_{1–x–y–z}Al_xTa_ySi_zN coatings under uniaxial tension is investigated. The nanoindentation method has shown that the coating with z = 0.10 has the maximum hardness, which is caused by the formation of a thin grain-boundary amorphous SiN_x phase. At the same time, the Ti_0.35Al_0.40Ta_0.10Si_0.15N coating showed the highest fracture resistance and adhesive strength. It is found that this effect is due to the suppression of the growth of columnar grains in this coating and the formation of a two-phase amorphous-nanocrystalline structure, which makes it difficult for cracks to propagate.