摘要
利用电化学测试、SEM、EDS、XPS等方法研究了AlCoCrFeNi2.1 共晶高熵合金(EHEA)在0.05 mol/L H2SO4 溶液与0.05 mol/L H2SO4 + 0.02 mol/L NaCl溶液中的腐蚀行为.结果表明,AlCoCrFeNi2.1 EHEA在H2SO4溶液中的钝化行为与局部腐蚀受Cl-影响明显;Cl-不改变AlCoCrFeNi2.1 EHEA钝化膜的半导体类型,但对钝化膜的致密性影响明显;钝化膜中的Ni受Cl-影响较小,Cl-主要通过影响Al、Cr氧化物的含量进而改变钝化膜的性质;在0.05 mol/L H2SO4溶液中,AlCoCrFeNi2.1 EHEA的腐蚀为富Ni-Al相选择性溶解;在0.05 mol/L H2SO4 + 0.02 mol/L NaCl溶液中,则为点蚀与选择性溶解.
Abstract
Several high-entropy alloys(HEAs),such as single-phase bcc HEA with high strength and fcc with high ductility have been developed over the past few decades.Eutectic HEA(EHEA),such as Al-CoCrFeNi2.1,consists of both fcc and bcc microstructure,imparting excellent mechanical properties.The recent research on AlCoCrFeNi2.1 EHEA primarily focuses on its mechanical properties.However,corro-sion resistance of AlCoCrFeNi2.1 EHEA is rarely discussed,which is crucial for the application of new ma-terials.This work investigates the corrosion behavior of AlCoCrFeNi2.1 EHEA in 0.05 mol/L H2SO4 and 0.05 mol/L H2SO4 + 0.02 mol/L NaCl solutions using electrochemical evaluation,SEM,EDS,and XPS.The results indicate that Cl-do not alter the semiconductor type of passive film on AlCoCrFeNi2.1 EHEA,but they considerably affect the compactness.Cl-change passive film properties by influencing the Al and Cr oxide contents;however,Ni is not affected by Cl-.The Ni-Al-rich phase is preferentially dissolved in 0.05 mol/L H2SO4 solution,and pitting corrosion and selective dissolution occur in 0.05 mol/L H2SO4 +0.02 mol/L NaCl solution.
基金项目
广东省区域联合基金-青年基金(2021A1515110560)
万方数据