激光熔覆制备Al-70Si组织及性能研究

Microstructure and properties of Al-70Si prep-ared by laser cladding

采用LWS-1000型Nd:YAG激光器在1050铝合金表面多层激光熔覆制备Al-70Si,观察和测试分析了Al-70Si的宏微观组织和相关力学性能,并探究了热处理对熔覆层的影响。结果表明:脉冲激光加工技术可以成功制备Al-70Si材料,熔覆层中硅颗粒自基体侧起分别呈现圆润球状、长条状、五星瓣状,熔覆层平均硬度值达到250 HV,抗拉强度为85 MPa,基体耐磨性能明显提高。进行500℃保温4 h热处理后,硅颗粒尺寸降低且尖角钝化,更为圆润,硬度值上升50 HV,热导率也相应提高。

Al-70Si alloy was prepared by multi-laser cladding on 1050 aluminium alloy with LWS-1000-Nd:YAG laser.The microstructure and mechanical properties of Al-70Si cladding layer were investigated.The effect of heat treatment on microstructure and properties of cladding layer were explored.The results show that Al-70Si alloy is successfully fabricated by laser processing technology.In the cladding layer,the morphology of silicon particles are cha-racterized by round spherical shape,long strip shape and five-star petal shape respectively.The average hardness of the cladding layer is 250 HV,the tensile strength is 85 MPa,and the wear resistance of the substrate is obviously imp-roved.After heat treatment at 500℃for up to 4 h,because of the reduction of silicon particle size and more rounded silicon particles,the maximum value of cross-section har-dness is improved by 50 HV and the thermal conductivity also increases accordingly.