The effects of chlorine content on the properties of titanium carbonitride thin film deposited by plasma assisted chemical vapor deposition

Abstract

Wear resistant titanium carbonitride (TiCxNy) films were deposited onto high speed steel (AISI M2) by plasma assisted chemical vapor deposition using the gaseous mixture of TiCl4, CH4, N2, H2, and Ar. The effects of deposition conditions on the deposition rate and residual chlorine content were investigated. The influences of the chlorine on the crystallinity, microstructure, and mechanical properties of coatings were also studied. It was found that the residual chlorine content in the films greatly varied with the deposition conditions. Subsequently the crystallinity of the TiCxNy films deteriorated with the increase in the chlorine content. The microhardness and adhesion strength also decreased with the chlorine content. However, in spite of the low residual chlorine content, TiCxNy film deposited at high radio-frequency power shows inferior mechanical properties due to the micropore network structure.