激光熔覆WC-Co涂层及耐磨性研究进展

Research Progress on Wear Resistance of Laser Welded WC-Co Coatings

摘要:

激光熔覆因其冶金结合好、热影响区窄等优势被广泛应用于钛合金等金属的表面强化。在各种强化材料中以WC为超硬陶瓷相，通过与Co的协同作用，能有效提升熔覆层的硬度和耐磨性，然而研究发现激光功率对熔覆层质量有显著影响，功率过高时WC颗粒过度溶解，容易萌生裂纹和气孔；功率过低时容易产生未熔颗粒和孔隙等缺陷；本文重点综述了激光功率对涂层中WC晶粒尺寸及生长机制的影响规律，总结了涂层的耐磨机制。同时，分析了当前制备WC-Co涂层存在的主要局限性及相应的改善措施，最后对存在的问题及未来发展趋势进行了展望。

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 utilized as a superhard ceramic phase. Through its synergistic effect with Co, the hardness and wear resistance of the clad layer can be effectively enhanced. However, research has demonstrated that laser power exerts a significant influence on clad 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 focuses on the influence of laser power on WC grain size and growth mechanisms within the coating, summarizing the coating's wear resistance mechanisms. Furthermore, the main limitations currently encountered in the preparation of WC-Co coatings are analyzed, along with corresponding improvement strategies. Finally, existing challenges and future development trends are discussed.