Effects of surface roughness of substrate on properties of Ti/TiN/Zr/ZrN multilayer coatings
(1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China;
2. Department of New Materials, Guangdong General Research Institute of Industrial Technology
(Guangzhou Research Institute of Nonferrous Metals), Guangzhou 510650, China)
2. Department of New Materials, Guangdong General Research Institute of Industrial Technology
(Guangzhou Research Institute of Nonferrous Metals), Guangzhou 510650, China)
Abstract: Ti/TiN/Zr/ZrN multilayer coatings were deposited on Cr17Ni2 steel substrates with different surface roughnesses by vacuum cathodic arc deposition method. Microstructure, micro-hardness, adhesion strength and cross-sectional morphology of the obtained multilayer coatings were investigated. The results show that the Vickers hardness of Ti/TiN/Zr/ZrN multilayer coating, with a film thickness of 11.37 μm, is 29.36 GPa. The erosion and salt spray resistance performance of Cr17Ni2 steel substrates can be evidently improved by Ti/TiN/Zr/ZrN multilayer coating. The surface roughness of Cr17Ni2 steel substrates plays an important role in determining the mechanical and erosion performances of Ti/TiN/Zr/ZrN multilayer coatings. Overall, a low value of the surface roughness of substrates corresponds to an improved performance of erosion and salt spray resistance of multilayer coatings. The optimized performance of Ti/TiN/Zr/ZrN multilayer coatings can be achieved provided that the surface roughness of Cr17Ni2 steel substrates is lower than 0.4 μm.
Key words: Ti/TiN/Zr/ZrN multilayer coatings; surface roughness; sand erosion resistance; corrosion resistance; vacuum cathodic arc deposition; TiN; ZrN