基于晶界特征分布优化的FCC高熵合金耐蚀性提升  

Improving Corrosion Resistance of FCC High-entropy Alloy Via Grain Boundary Character Distribution Optimization

作　　者：唐群华 彭世龙 王浩 戴品强 TANG Qunhua;PENG Shilong;WANG Hao;DAI Pinqiang(School of Mechanical,Electrical&Information Engineering,Putian University,Putian Fujian 351100,China;College of Materials Science and Engineering,Fuzhou University,Fuzhou Fujian 350002,China;School of Materials Science and Engineering,Fujian University of Technology,Fuzhou Fujian 350002,China)

机构地区：[1]莆田学院机电与信息工程学院,福建莆田351100 [2]福州大学材料科学与工程学院,福建福州350002 [3]福建工程学院材料科学与工程学院,福建福州350002

出　　处：《莆田学院学报》2023年第2期47-52,共6页Journal of putian University

基　　金：福建省自然科学基金面上项目(2019J01812);莆田市科研创新专项(2021ZP06)。

摘　　要：采用电子背散射衍射、动电位极化曲线和电化学交流阻抗谱技术,针对FCC结构单相CoCrFeMnNi高熵合金,研究10%~40%冷轧退火合金的晶界特征分布(GBCD)及其在0.5 mol·L-1H2SO4溶液中的电化学行为。结果表明:10%冷轧退火使特殊晶界比例提升到初始状态(45%)的1.6倍(71.4%),组织形成大尺寸晶粒团簇,即实现了GBCD优化,而20%~40%冷轧退火导致特殊晶界比例显著下降。10%冷轧退火对该合金GBCD的优化,降低其自腐蚀电流密度至3.990×10-6A·cm-2、提高膜层电阻至4.666×104Ω·cm2以及增大电荷传递电阻至3 770Ω·cm2,使该合金表现出优异的耐蚀性。揭示了钝化膜致密性是控制该合金电化学反应的主导因素,提升特殊晶界比例可改善钝化膜致密性,促使膜层电阻急剧增大。The grain boundary character distribution(GBCD)and electrochemical behavior in 0.5 mol·L-1 H 2SO 4 of 10%~40%cold-rolled and annealed FCC CoCrFeMnNi high-entropy alloy are investigated by electron backscatter diffraction,polarization curves and AC impedance measurements.The results show that after 10%rolling and annealing,the special boundary(SB)ratio of 71.4%is 1.6 times than that at the initial state and the GBCD optimization is achieved after the formation of large-size grain clusters.However,the 10%~40%cold-olled reduction is related to a significant decrease in SB ratio.The GBCD optimization corresponding to 10%cold-rolled reduction can dramatically reduce self-corrosion current density to be 3.990×10-6 A·cm-2,increase film resistance to be 4.666×104Ω·cm 2,and improve charge transfer resistance to be 3770Ω·cm 2,indicating optimal corrosion resistance.It is proved that the passivation film denseness is a dominant factor controlling its electrochemical response,while the increase in SB ratio can induce a sharp increase in the film resistance to improve the passivation film denseness.

关 键 词：高熵合金 晶界特征 组织结构 耐蚀性 

分 类 号：TG139[一般工业技术—材料科学与工程]