Ni元素对AlFeCoCrCuNi_x高熵合金组织及电化学腐蚀性能的影响

Effects of Ni Addition on the Microstructure and Electrochemical Corrosion Property of AlFeCoCrCuNi_x High-entropy Alloys

利用XRD、SEM、EDS以及电化学极化曲线,研究不同含量Ni元素对铸态AlFeCoCrCuNix(x=0、0.25、0.5、1)多组元高熵合金的微观组织及电化学腐蚀性能的影响。结果表明,四种成分的合金均呈典型的树枝晶结构,组织中伴有成分偏析现象,其中Cu元素大量聚集于晶界。加入少量Ni元素使合金内部形成颗粒状Al-Ni第三相,且随着Ni含量的增加,颗粒状分布的Al-Ni相演变为聚集于富Cu晶界与枝晶之间的大块相。加入Ni使AlFeCoCrCuNix(x=0、0.25、0.5、1)合金在3.5%NaCl溶液中的耐腐蚀性能得到了提升,其中AlFeCoCrCuNi0.5的耐蚀性能最好。

The influences were investigated of different amounts of Ni element on the microstructure and electrochemical corrosion property of AlFeCoCrCuNix(x=0,0.25,0.5,1)high-entropy alloys by XRD,SEM,EDS and electrochemical polarization curves.The results show that all the alloys exhibit dendritic microstructure with composition segregation,and Cu element is enriched in interdendritic boundaries.Adding a small amount of Ni element results in the formation of granular Al-Ni new phase.With the increase of Ni content,the granular Al-Ni new phase develops into a massive phase distributed between Curich boundary and dendrite.Furthermore,the addition of Ni element improves the corrosion resistance of AlFeCoCrCuNix(x=0,0.25,0.5,1)alloy in 3.5% NaCl solution.And AlFeCoCrCuNi0.5alloy exhibits the optimal corrosion resistance.