激光增材制造技术是一种典型的快速成形技术, 运用高能激光束熔化金属粉末逐层堆积, 可直接成形复杂高性能金属零部件。采用激光增材制造技术沉积镁合金, 研究了Zr元素对镁合金的组织及性能的影响。采用金相显微镜、扫描电子显微镜(SEM)、维氏硬度计及XRD衍射仪对沉积试样进行相关分析。结果表明, 激光增材制造镁合金的晶粒粒径(约10 μm)比传统铸造法得到的晶粒(约500 μm)更为细小; 与此同时, 和传统铸造法相比, 增材制造试样的硬度也有明显的提高。在金属粉末中添加适量的Zr元素后, Zr在α-Mg结晶过程起到异质形核的作用使沉积试样晶粒得到进一步细化, 同时硬度也有提高达到70.0 HV。

Laser additive manufacturing(LAM) technology has been developed as a new advanced rapid prototyping technology. Metal parts with advanced properties and complexity were directly manufactured with the SLM technology. Influence of Zr element on microstructure and properties of magnesium alloy by laser additive manufacturing was investigated. The as-deposited samples were analyzed by optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction and Vickers hardness tester. The results show that the grain size of the magnesium alloy (about 10 μm) by laser additive manufacturing is finer than traditional casting methods obtained (about 500 μm). Meanwhile, compared with conventional casting methods, the hardness of the sample fabricated by laser manufacturing is also significantly improved. The addition of some Zr element played the role of heterogeneous nucleation in the metal powder. The deposited sample is further refined, while the hardness is also improved and reached to 70.0 HV.