Effect of Negative Bias Voltage on Corrosion Resistance of TiN Coating Deposited by MAIP

Abstract

In this study, TiN coatings were deposited on 201 stainless steel by multi-arc ion plating (MAIP). The effect of negative bias voltage on the surface microstructure, hardness, phase structure and the corrosion resistance of the coatings were investigated by SEM, hardness instrument, XRD and electrochemical measurement. The number and size of droplets decreased when the negative bias voltage increased from -100 V to -300 V. But when the substrate bias increased to a certain value, there were some pits appeared. The hardness increased at first and decreased later with the increasing of the negative bias voltage. When the negative bias voltage was -200 V, the hardness was the highest. The intrinsic hardness of TiN film was 2195HV. In 3.5% NaCl solution, the corrosion resistance of TiN coatings samples were improved slightly compared with 201 stainless steel. In l mol/L H2SO4 solution, the corrosion resistance of -100V sample was the best, the corrosion resistance of -100V coating sample was increased 486 times compared with untreated 201 stainless steel.