FeCrNiCo(Cu/Mn)高熵合金组织及腐蚀性能

Microstructure and corrosion property of FeCrNiCo(Cu/Mn)high entropy alloys

采用电弧熔炼方法制备了FeCrNiCoCu及FeCrNiCoMn两种高熵合金,借助第一性原理模拟计算及腐蚀电化学测试技术,研究Cu、Mn元素对制备高熵合金在3.5%NaCl、5%NaOH和0.5 mol/L H2SO4溶液中的电化学腐蚀行为的影响规律。结果表明:FeCrNiCoCu及FeCrNiCoMn高熵合金均为单一的FCC结构,其中FeCrNiCoMn态密度达到最大值时对应的能量较低,结构更趋于稳定,耐蚀倾向性好。FeCrNiCoMn高熵合金在三种溶液中的耐蚀性均高于FeCrNiCoCu的,这是由于Cu元素的存在会引起元素偏聚,降低了合金的耐蚀性。而Mn元素以金属间化合物的形式存在,降低了合金中耐蚀性差的元素含量,提高了合金的耐蚀性。

FeCrNiCoCu and FeCrNiCoMn high-entropy alloys were prepared by means of arc melting.The firstprinciples simulation and corrosion electrochemical testing methods were used to investigate the effects of Cu and Mn elements on the corrosion resistance of FeCrNiCo high-entropy alloys in 3.5%NaCl,5%NaOH and 0.5 mol/L H2SO4 solutions.The results show that FeCrNiCoCu and FeCrNiCoMn high-entropy alloys both exhibit single FCC structure.When the density of states of FeCrNiCoMn reaches its maximum,the corresponding energy is lower,the structure is more stable and the corrosion resistance tendency is decreased.The corrosion resistance of FeCrNiCoMn high entropy alloy in three solutions is higher than that of FeCrNiCoCu.The main reason is that the presence of Cu can aggravate element segregation and reduce the corrosion resistance of the alloy.However,Mn element exists in the form of an intermetallic compound,which reduces the content of poor corrosion resistance elements in the alloy,and the corrosion resistance of the alloy is improved.