AZ33M镁合金激光熔覆Al-Si涂层的组织与性能  

Microstructure and properties of laser clad Al-Si coating on AZ33M magnesium alloy

作　　者：王鑫 潘希德[1] 牛强 何向前 Wang Xin;Pan Xide;Niu Qiang;He Xiangqian(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an Shaanxi 710049,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049

出　　处：《金属热处理》2021年第5期202-206,共5页Heat Treatment of Metals

摘　　要：利用激光熔覆技术在AZ33M镁合金表面制备了Al-Si涂层,通过采用腐蚀电化学测试结合X射线衍射仪(XRD)、扫描电镜(SEM)及显微硬度计等对熔覆层微观组织和性能进行了表征。结果表明,熔覆层主要由Mg和Mg_(17)Al_(12)、Mg_(2)Si及Mg_(2)Al_(3)相组成。熔覆层显微组织由柱状树枝晶和方向各异的树枝晶组成。由于第二相强化和细晶强化等原因,制备的Al-Si涂层相比镁合金基体具有更高的硬度。熔覆层的自腐蚀电位相比基体提高了约400 mV,自腐蚀电流降低了一个数量级,熔覆层的耐蚀性明显优于基体镁合金。Al-Si coating was prepared on the surface of AZ33M magnesium alloy by laser cladding technology.The microstructure and properties of the clad layer were characterized through corrosion electrochemical method test combined with X-ray diffractometer(XRD),scanning electron microscope(SEM),microhardness tester,etc..The results show that the clad layer is mainly composed of Mg matrix,Mg_(17)Al_(12),Mg_(2)Si,and Mg_(2)Al_(3) phases.The microstructure is composed of columnar dendrites and dendrites with different directions.Due to second phase strengthening and fine-grain strengthening,the prepared Al-Si coating has higher hardness compared with magnesium alloy matrix.Compared with the matrix,the self-corrosion potential of the clad layer is increased by 400 mV,the self-corrosion current is reduced by an order of magnitude,and the corrosion resistance of the clad layer is significantly better than that of the magnesium alloy matrix.

关 键 词：激光熔覆 镁合金 AL-SI共晶合金 耐蚀性 硬度 

分 类 号：TG146[一般工业技术—材料科学与工程]