MECHANICAL PROPERTIES AND ANTI-WEARABILITY STUDIES OF MULTILAYER THIN COATINGS ON CUTTING TOOLS

摘要

The nanoindentation fracture of multilaryer hard coatings, such as TiN, TiN/Ti(C,N)/TiC, TiN/Ti (C,N)/TiC/Ti(C,N)/TiN/TiC and TiN/Ti(C,N)/tiC/ti(C,N)/TiC/ti(C,N)/TiC coatings, deposited on cemented carbide using a VCD technique are studied. It is found that these coatings have high hardness. Based on the analysis of the energy release in cracking, the fracture toughness of these coatings are calculated. The observations clearly establish a step occurs in the force-displacement curves at the onset of coating fracture and a straight line segment in the load-penetration depth squared curves to identify the interfacial failure of coatings. The hardness, fracture toughness and anti-wearability of these coatings are clearly compared. The results show That with the layers increasing, the fracture toughness and anti-wearability are getting larger.