Effects of pulsed bias duty ratio on microstructure and surface properties of TiN films

TiN films were deposited on 1Cr18Ni9Ti stainless steel substrates using an arc ion plating system. The duty ratio effects on the surface morphology, thickness, microstructure, hardness and corrosion properties were investigated. With the increase of duty ratio, the amount of the macroparticles reduced and the surface roughness was 0.074 μm at 60% duty ratio. The TiN films presented the strong (111) preferred orientation. But other planes didn't vary greatly. The measured hardness of TiN films reached a maximum hardness of 1160 HV at 60% duty ratio. The TiN film deposited at 40% duty ratio showed the best resistance performance to corrosion. The corrosion current density of TiN coated samples at 40% duty ratio was two orders of magnitude lower than that of the uncoated ones.