镁合金表面电火花处理及其耐蚀性研究  

Research on Electric Spark Processing on Mg Alloy Surface and Its Corrosion Resistance

作　　者：王波[1] 王庭俊[1] 

机构地区：[1]扬州工业职业技术学院机械工程学院,江苏扬州225127

出　　处：《热加工工艺》2015年第8期158-160,163,共4页Hot Working Technology

摘　　要：通过电火花堆焊工艺,在AZ31镁合金基体上制备了铝堆焊层。试样经封闭处理后,在3.5%的Na Cl溶液中进行浸泡腐蚀。利用扫描电镜、能谱分析仪对复合涂层表面、截面形貌及元素组成进行分析。结果表明:在电压40 V、频率300 Hz的工艺参数下,纯铝焊丝电火花堆焊的涂层缺陷最少,且与基体发生冶金结合。铝涂层在3.5%的Na Cl溶液中发生钝化,涂层边界发生缝蚀,铝涂层表面腐蚀形貌为点蚀坑,与基体大面积沟壑状腐蚀形貌相比,试样耐蚀性得到了大幅度提高。Aluminum cladding layer was prepared on the substrate of AZ31 Mg alloy via the optimum process of electric spark welding. The sample was immersed and corroded in 3.5% NaCl solution after closed treatment. Morphology and elemental composition of the composite coating surface and section were analyzed through SEM and EDS. The results show that the coating has the least defects and it existes metallurgical bond with the substmte when the voltage of electric spark welding is 40 V and the frequency is 300 Hz. The aluminum coating produces the phenomenon of passivation in 3.5% NaC1 solution, coating boundary occures seam corrosion and the surface of aluminum coating appeares pitting holes. Corrosion resistance of the sample is improved greatly compared with the corrosion phenomenon of large gully-like substrate.

关 键 词：镁合金 电火花堆焊 耐蚀性 

分 类 号：TG174[金属学及工艺—金属表面处理]