Effects of deposition parameters on the properties of chromium carbide coatings deposited onto steel by sputtering

Chromium carbide films were deposited on high speed steels using a Cr3C2 target by magnetron sputtering. Effects of the deposition parameters (power, Ar pressure and substrate temperature) on deposition rates and surface roughnesses of the films were investigated. The crystal structures and morphologies of those films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The as-deposited Cr3C2 films of most of the samples are amorphous in nature. The grain size of the samples deposited using dc-power is larger than that using equivalent rf-power. The hardness of the sample increases with increasing rf-power, whereas the elastic modulus nearly does not change with rf-power. The optimum sputter deposition conditions for Cr3C2 on high speed steels in the corrosion resistance aspect were found to be the dc-power of 200 W, the pressure of 7 mTorr and room temperature.