AZ91D镁合金表面激光熔覆Al-Ti-C涂层的显微组织和性能

为了提高镁合金的耐磨损性能,使用1kW脉冲激光在镁合金基体上熔覆Al-Ti-C混合粉末(粉末中质量比Ti∶C=1∶1,Al质量分数为20%～40%)。使用的激光能量密度分别为1.67、1.89、2.20、2.65和3.14×109W/m2,扫描速度在0.5～2.5mm/s内变化;对在不同激光工艺参数下获得的熔覆层微观组织进行了观察,并对其硬度和耐磨损性能进行了检测。结果表明:当粉末中Al的质量分数为40%,激光扫描速度为1.0mm/s,激光能量密度为2.20×109W/m2时,表面硬度可达到HV210,耐磨损性能约为未处理表面的4倍左右。

Microstructure and propoerties of the coating formed by laser cladding of Al-Ti-C powders on magnesium

An attempt has been made to enhance the wear resistance of AZ91magnesium alloy by laser surface cladding Al-Ti-C powders(in the weight ration Ti∶C=1∶1,Al content ranges from 20%-40%) using a 1kW Nd:YAG pulsed laser.The experiment was performed using different laser power densities of 1.67,1.89,2.20,2.65and 3.14×109 W/m2,and scan speed ranging from 0.5mm/s to 2.5mm/s.The microstructure of the modified surface layer was examined,the hardness and wear resistance were measured.The results showed that a cladding layer with a hardness of HV210and 4 times as wear resistant as the untreated material was prepared using apowder containing 40%Al under the laser scan speed of 1.0mm/s,laser power density of 2.20×10 9 W/m2.