激光熔覆钴基合金涂层的组织与耐磨性

Microstructure and wear resistance of Co-based alloy coating fabricated by laser cladding

利用激光熔覆技术在蠕墨铸铁表面制备了钴基合金涂层,用SEM和EDS对熔覆层和结合区进行了组织和成分分析,并利用显微硬度计和摩擦磨损试验机对其进行了显微硬度和抗摩擦磨损性能测试。试验结果表明,当激光功率为3 kW、光斑尺寸为4 mm×2 mm、激光扫描速度v=8 mm/s时,熔覆层没有夹渣和孔隙,熔覆层与基体之间形成了冶金结合;熔覆层晶粒细小,偏析范围小,符合快速凝固的过程。钴基合金涂层可以有效的提高蠕墨铸铁表面的硬度和抗摩擦磨损性能。

Co-based alloy coating was fabricated on compacted graphite cast iron specimen by laser cladding. The SEM and EDS were used to analyze the microstructure and composition of the clad layers and the interface layer. Their performances of micro-hardness and wear resistance were tested by the micro hardness tester and wear tester. Experimental results show that when the laser power is 3 kW, spot size is 4 mm × 2 mm, and the laser scanning velocity reaches 8 mm/s, there is no clip powder or pores, a metallurgical bonding forms between clad layer and substrate, and the clad layer has fine grain size and small distance of segregation, and is in line with the rapid solidification process. Co-based alloy coating can effectively improve the surface hardness and wear resistance of the compacted graphite cast iron.