Research Progress on Laser Cladding WC-Co Coatings and its Wear Resistance

Abstract:

Laser cladding is widely employed for surface strengthening of titanium alloys and other metals owing to its advantageous metallurgical bonding and narrow heat-affected zones. Among various strengthening materials, WC is used as a superhard ceramic phase. Through its synergistic effect with Co, the hardness and wear resistance of the cladding layer can be effectively enhanced. However, research has demonstrated that laser power exerts a significant influence on cladding layer quality. When excessive power is applied, excessive dissolution of WC particles occurs, facilitating crack initiation and pore formation. Conversely, insufficient power commonly leads to defects, such as unmelted particles and porosity. This review focused on the influence of laser power on WC grain size and growth mechanisms within the coating, and summarized the wear resistance mechanisms of the coating. Furthermore, the main limitations currently encountered in the preparation of WC-Co coatings were analyzed, along with corresponding improvement strategies. Finally, existing challenges and future development trends were discussed.