Study Of Characterization And Preparation Of Zirconium Nitride Films On AZ31Magnesium Alloy Substrates By Vacuum Arc Ion Plating And Mid-frequency Magnetron Sputtering

Magnesium (Mg) alloys have attracted much attention for their low density, high specific strength and rigidity, good electromagnetic shielding performance and heat conductivity. They are widely used in the aerospace, automotive, electronics and many other fields. However, the poor corrosion resistance and mechanical properties of Mg alloys limit their development and application. Therefore, it is of great significance to improve the corrosion resistance and mechanical properties of Mg alloy by taking the surface modification technology. ZrNx (Zirconium Nitride) thin films is a kind of important decorative materials for their golden yellow, good chemical stability, high temperature resistance, corrosion resistance, abrasion resistance, and it can be applied to high temperature structural, ultra hard tools and surface protection materials.In order to improve the corrosion resistance and mechanical properties of AZ31Mg alloys, ZrNx thin films were deposited onto the AZ31Mg alloys substrate by vacuum cathode arc ion plating and mid-frequency magnetron sputtering methods.Cathode arc ion plating method was used to prepare ZrNx films on Z31Mg alloys substrate and the influences of various currents on deposition rate, microstructure, friction coefficient, microhardness and corrosion resistance et al. were investigated. The stylus profile measures the films thickness and surface roughness; X-ray diffraction (XRD) analyzes the microstructure of the films; Friction and wear tester and microhardness instrument measure the film coefficient of friction and microhardness; the electrochemical corrosion system tests the corrosion resistant of the films. The research results show that the deposition rate of ZrNx films prepared by cathode arc ion plating increased with increasing current; the surface roughness of ZrNx films increased with increasing current; the XRD patterns of ZrNx films were mainly composed of ZrN(200) diffraction peak and his height increased with increasing current; the corrosion potential of the films decreased with increasing current; the friction coefficient of the films increased with increasing current; the hardness of the films increased with increasing current.In the same way, mid-frequency magnetron sputtering method was used to deposit ZrNx films on Z31Mg alloys substrate and we investigated the influence of different N2flow to deposition rate, microstructure, friction coefficient, microhardness and corrosion resistance. The research results show that the deposition rate of ZrNx films prepared by mid-frequency magnetron sputtering decreased with increasing N2flow; the surface roughness of ZrNx films decreased with increasing N2flow; the XRD patterns of ZrNx films were composed of ZrN(111) and ZrN(200) diffraction peaks and their heights increased with increasing N2flow; the corrosion potential of the films increased with increasing N2flow; the friction coefficient of the films decreased with increasing N2flow; the hardness of the films decreased with increasing N2flow.Based on above analysis of the properties of ZrNx films deposited by vacuum cathode arc ion plating and mid-frequency magnetron sputtering methods, respectively, uch conclusions are arrived:ZrNx films deposited by mid-frequency magnetron sputtering has a higher corrosion potential, lower deposition rate, lower roughness as well as is conductive to enhance the corrosion resistance, while ZrNx films deposited by cathode arc ion plating has a higher deposition rate, higher hardness, higher roughness as well as is beneficial to improve the mechanical properties.