Effects of Cr content on microstructure and tribological properties of laser cladding Ti-based coatings

Ti-Al-Si-SiC-Crx (X = 0, 5, 10, 15) coatings were prepared on TC4 alloy by laser cladding, and their microstructure and tribological properties were investigated. The results reveal that the coatings consist of Ti3Al, TiC, Ti5Si3, and Ti4Cr phases. In room temperature friction, with the addition of Cr, Ti4Cr soft phase was formed in the coating, which reduced the three-body wear of the coating. However, an excess of Ti4Cr soft phase induces a reduction in the wear resistance of the coating. Under high temperature friction conditions, due to the addition of Cr, a super-hard amorphous oxide protective layer is formed on the wear surface to improve the wear resistance of the coating. Therefore, Ti-Al-Si-SiC-Cr10 coating has the best tribological properties.