On enhancing wear resistance of titanium alloys by laser cladded WC-Co composite coatings

Abstract

WC-Co composites comparable to titanium in thermal expansion coefficient can be used as wear-resistant coatings, extending the applications of titanium alloys. This study aims to investigate the effect of laser power on the quality of composite coatings on the Ti-6Al-4 V substrate, and to study the phase constituents comprehensively, microstructural evolution, microhardness, and wear behavior of composite coatings. The experimental results show that there is a good metallurgical bonding between the WC-Co composite coatings with high densification and the substrate. Furthermore, a considerably high microhardness up to 1536 HV0.5, and a wear rate of 1.5 g/h were achieved owing to the synergistic effect of excellent metallurgical bonding and fine microstructures of the composite coating under laser power of 2000 W. Based on the experimental results, the process-structure-properties relationship of laser cladded WC-Co composite was established. It is expected to be applied to improve the wear resistance of petroleum titanium alloys in deep and ultra-deep wells.