不同激光功率对AZ31B镁合金表面Al-Cu合金熔覆层组织和性能的影响

Influence of Different Laser Power on Microstructrue and Properties of Al-Cu Cladding Coating on AZ31B Alloy

采用激光熔覆技术在AZ31B镁合金表面制备Al-Cu合金涂层,研究不同激光功率条件下激光熔覆层成形、组织和性能的差异。结果表明,当激光功率为350 W时,熔覆层表面成形良好,与基体结合良好并无明显的裂纹缺陷。当激光功率过小时,熔覆表面出现金属小球,且熔覆层与基体结合处有明显的裂纹;当激光功率过高时,熔覆层表面会有弧坑裂纹。不同功率下得到的熔覆层对基体的硬度有明显提高,当功率为350 W时,熔覆层的平均显微硬度达到325 HV。

Al-Cu cladding coatings were prepared on AZ31B alloy by laser cladding. The influences of laser power on the formation, microstructure and property of the cladding coatings were investigated. The results show that when the laser power is 350 W, the cladding coating which has good bonding with substrate possesses excellent formation and there is no apparent defects such as cracks. But when the power is too low, the formation of the coating is bad with many small un-melted metal balls and there are cracks in bonding interface. When the laser power is too high, the surface of the coating is subsidence with craters and cracks. The laser cladding coatings with different parameters can improve the hardness of the substmte. When laser power is 350 W, the average microhardness of the coating is 325 HV.