Cooperative effect of Cr and Al elements on passivation enhancement of eutectic high-entropy alloy AlCoCrFeNi_(2.1)with precipitates  

作　　者：Xiaotian Duan Tiezhuang Han Xiao Guan Yuning Wang Huhu Su Kaisheng Ming Jing Wang Shijian Zheng 

机构地区：[1]State Key Laboratory of Reliability and Intelligence of Electrical Equipment,Hebei University of Technology,Tianjin 300130,China [2]School of Material Science and Engineering,Hebei University of Technology,Tianjin 300130,China

出　　处：《Journal of Materials Science & Technology》2023年第5期97-108,共12页材料科学技术（英文版）

基　　金：This work was financially supported by the Natural Science Foundation of Hebei Province(No.E2020202009);the Tianjin Science and Technology Plan Project(No.20JCQNJC00900);the Science and Technology Project of Hebei Education Department(No.QN2020150);the National Natural Science Foundation of China(No.52101011);the Central Funds Guiding the Local Science and Technology Development of Hebei Province(No.226Z1001G);the Central Funds Guiding the Local Science and Technology Development of Hebei Province(No.226Z1012G).

摘　　要：In conventional corrosion-resistant alloys,precipitation usually reduces corrosion resistance severely by weakening passive films locally.In this work,we found that the aging-treated AlCoCrFeNi_(2.1)sam-ples,which have abundant nanosized L 12 and body-centered cubic(BCC)precipitates in the lamellar face-centered cubic(FCC)and B2 phases,displayed better corrosion resistance than solution-treated AlCoCrFeNi_(2.1)samples without precipitates.In the AlCoCrFeNi_(2.1)alloy,the FCC phase with L1_(2)precipi-tates and the B2 phase with BCC precipitates were protected by passive films enriched with Cr and Al elements,respectively.Moreover,the Al-rich passive film of the B2 phase was less stable than the Cr-rich passive film of the FCC phase,so B2 phase dissolved preferentially.The Cr-rich passive film of the FCC phase remained stable with the formation of Al-rich L1_(2)precipitates inside the phase because those precipitates with the size of∼5 nm were too small to affect the composition of the Cr-rich passive film.The formation of Cr-rich BCC precipitates within the B2 phase increased the content of the Al element inside the phase,improving the stability of Al-rich passive film on the B2 phase.Furthermore,BCC precip-itates with the size of∼30 nm were protected by Cr-rich passive film,which could inhibit the expansion of corrosion pits.Thus,the corrosion resistance of eutectic high-entropy alloy AlCoCrFeN 2.1 was unprece-dentedly enhanced by the precipitation of BCC precipitates.Our study could provide an attractive strategy for designing high-entropy alloys with excellent corrosion resistance and high strength.

关 键 词：Eutectic high-entropy alloy Passive film Corrosion resistance PRECIPITATES TEM 

分 类 号：TG139[一般工业技术—材料科学与工程]