Effect of high-voltage pulse bias on the stress and morphology of CA-PVD TiN coatings

Abstract

ABSTRACTWe investigated the role of high-voltage pulse bias (HVPB) on the structure, morphology and residual stress of TiN coatings produced with cathodic arc physical vapour deposition and compared them with the ones produced with DC bias. Annealing heat treatment was also performed for surveying stress-relieving behaviour within the coatings. The preferred orientation of the coatings changed from (111) to (220) by the application of HVPB. Coatings produced with DC bias exhibited Zone T structure, while the growth morphologies of the coatings produced with HVPB were very similar to the structures in the beginning of Zone II. The presence of Ar in the deposition environment increased the residual stress of all coatings. Intra-grain stresses of the coatings produced with DC bias were almost totally annihilated by annealing. However, for coatings produced with HVPB, stress relief magnitudes were very low, indicating that intra-grain defects could not be totally annihilated.