异质结构CoCrFeNiW高熵合金的拉伸性能和强化行为

Tensile properties and strengthening behavior of CoCrFeNiW high entropy alloys with heterogeneous structures

高雪峰 ¹陈峣 ¹任浩 ¹秦刚 ¹周启文 ²陈瑞润 ¹郭景杰¹

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作者信息

1. 哈尔滨工业大学金属精密热加工国家重点实验室,哈尔滨 150001
2. 沈阳工业大学材料科学与工程学院,沈阳 110870
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摘要

采用真空电弧熔炼方法制备Co30Cr30(FeNi)40-xWx(x=0～8％(摩尔分数),分别简化为HW0～HW8)高熵合金.研究铸态和退火态合金的显微组织和拉伸性能.结果表明,HW2和HW4具有单一的FCC相.随着W含量和退火温度的增加,细小粒状μ相的面积分数增加且分散在FCC基体中.软FCC基体和硬μ相构成应变不相容的异质结构.随着W含量从0增加到8％(摩尔分数),屈服强度和抗拉强度分别从278和629 MPa提高到530和839 MPa,应变维持在33％.退火后的HW8表现出优异的屈服强度(810 MPa)和抗拉强度(1087 MPa).屈服强度的提高归因于固溶、沉淀和背应力强化.异质结构中产生的背应力强化作用诱导高硬化行为,在提高抗拉强度和塑性方面发挥着主导作用.

Abstract

Co30Cr30(FeNi)40-xWx(x=0-8 at.％,simplified as HW0-HW8,respectively)high entropy alloys(HEAs)were fabricated by vacuum arc-melting.The microstructure and tensile properties of as-cast and as-annealed alloys were investigated.The results show that HW2 and HW4 have a single FCC phase.The fine and granular μ phase is dispersed in FCC matrix and the area fraction increases with the increase of W content and annealing temperature.The soft FCC matrix and hard μ phase constitute the hetero structure with strain incompatibility.With the increase of W content from 0 to 8 at.％,the yield strength and tensile strength increase from 278 and 629 MPato 530 and 839 MPa,respectively.The strain maintains 33％.The as-annealed HW8 exhibits superior yield strength(810 MPa)and tensile strength(1087 MPa).The yield strength improvement is attributed to solid-solution,precipitate,and back stress strengthening.Back stress strengthening plays a dominant role in improving tensile strength and plasticity by inducing high hardening behavior in heterogeneous structures.

关键词

高熵合金/异质结构/拉伸性能/应变硬化/强化机制

Key words

high entropy alloy/heterogeneous structure/tensile properties/strain hardening/strengthening mechanism

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基金项目

国家自然科学基金(51825401)

出版年

2024

中国有色金属学报(英文版)

中国有色金属学会

中国有色金属学报(英文版)

CSTPCDCSCD

影响因子：1.183

ISSN：1003-6326

参考文献量45

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