Composite coating by TIG cladding with different rare earth oxides

Abstract

In this study, composite coating with different rare earth oxides has been performed to enhance the surface, mechanical and tribological properties of titanium alloy using the TIG cladding process. Three different rare earth oxides, CeO₂, La₂O₃ and Y₂O₃ were used in pairwise combination with WC and Ni powder. The cladding thickness, microstructure, phase analysis, microhardness and friction wear of coated samples were examined. The experimental results showed that mainly hard phases like NiTi and AlTi₂C were found in coatings. The sample prepared with RE oxides refines the coating grains and enhances the mechanical and tribological properties. The wear test analysis reveals a considerable decrease in coefficient of friction (COF). The mechanism for the wear of coating was adhesion. The coating done with CeO₂ and La₂O₃ has the highest microhardness (870 HV_0.5) and wear resistance (COF of 0.22), which confirmed that this combination of RE oxide is appropriate for surface modification.