On the wear behaviour of PVD Ti, Al, Zr, V, N coatings

Innovative hard compound belonging to the Ti-Al-N, Ti-Zr-N and Ti-Al-V-N system were developed in the light of experience with magnetron sputtered TiN coatings. All the compound coatings under investigation crystallized in a face-centered cubic TiN lattice whose lattice parameters were diminished or increased depending on the number and radii of the impurity atoms. No correlation was found between wear properties, impurity content and lattice distortion. Despite the highly favourable hardness and adhesion values exhibited by these ternary and quaternary compound films, wear behaviour was not excellent in all cases. Performance tests carried out with cutting tools demonstrated the outstanding wear properties of (Ti,Al)N, (Ti,Zr)N and (Ti,Al,V)N coatings. Wear behaviour for these innovative compound coatings showed a significant improvement as compared to that of CVD-TiN tools in current use, pointing to development of the coating material itself as a future focus of interest in this field