Abstract
Heat treatment processes were applied to enhance the characteristics of ZrN thin films. In this study, ZrN films were deposited on AISI D2 steel using a hollow cathode discharge ion-plating (HCD-IP) technique. Heating environment, including air, Ar/H2, and Zr and Ti getters were discussed with thermodynamic and kinetic analysis. The specimens were heat-treated at 700℃ for 1 hour under optimal atmosphere to reduce oxidation of the thin films. The microstructure, resistivity and packing factor of the heat-treated ZrN thin films were not significantly changed. However, the surface grain size was enlarged and crystalline improved. Preferred orientation of (111) was enhanced after heat treatment. Roughness of the annealed specimens was slightly degraded compared with as-deposited samples. The hardness decreased 26~38 %, this is to be understood that heating reduced the strength of the grain boundary. This also could be attributed to the reduction of defects. The residual stress of the specimens subjected to 700℃ heat treatment was relieved 8~24 % that could be due to the better crystallinity. Corrosion resistance became better after heat treatment; it was confirmed both in salt spray and potentiodynamic scanning.