铝合金表面激光熔覆Re+Ni60电化学腐蚀性能研究

Study on electrochemical corrosion resistance of laser cladding Re+Ni60 on aluminum alloy

为了改善铝合金材料的耐腐蚀性能,采用激光熔覆技术在6061Al表面分别制备了添加稀土(5%La2O3、5%CeO2和5%Y2O3)的Ni60合金的熔覆层,通过金相显微镜、XRD、电化学测量仪分别检测熔覆层的微观组织、物相和耐腐蚀性能,分析熔覆层在不同腐蚀介质溶液的电化学腐蚀行为。结果表明,未加入稀土的Ni60熔覆层截面形貌最差,熔覆层中出现大量的气孔和裂纹,熔覆层部分脱落。含有3种稀土的熔覆层厚度达到1000μm,无明显气孔和裂纹,具有较好的截面组织形貌;适量的稀土可改善熔池的流动性,有利于降低或消除熔覆层的气孔和裂纹缺陷,进而改善了熔覆层的耐腐蚀性能。

In order to improve the corrosion resistance of aluminum alloy material,the cladding layers of Ni60 alloy with rare earth (5%CeO 2,5%La 2O 3 and 5%Y 2O 3) was prepared respectively on the surface of 6061 Al by laser cladding technique.The micro-morphology,phase structure and corrosion resistance of cladding layers were studied by metallographic microscope,XRD and electrochemical method.The electrochemical corrosion behavior of the cladding layer in different corrosive medium solutions is mainly studied.The results showed that the cross-section morphology of the Ni60 cladding layer without rare earth is poor,a large number of pores and cracks appear in the cladding layer,and the cladding layer partially falls off.The cladding layers containing three kinds of rare earths have a thickness of about 1000 μm,no obvious pores and cracks,and have a good cross-sectional structure.Appropriate amount of rare earth can improve the fluidity of the molten pool,and is beneficial to reduce or eliminate the pores and crack defects of the cladding layer,thereby improving the corrosion resistance of the cladding layer.