摘要
BCC(体心立方)和FCC(面心立方)结构共存的高熵合金通常具有优异的综合力学性能,Al元素可以促进含Cu高熵合金由FCC向BCC结构转变.本文基于Chan-Hilliard方程和Allen-Cahn方程,建立Al_(x)CuMnNiFe高熵合金三维相场模型,模拟了Al_(x)CuMnNiFe高熵合金(x=0.4,0.5,0.6,0.7)在823 K等温时效时纳米富Cu相的微观演化过程.结果表明,Al_(x)CuMnNiFe高熵合金时效时会产生两种复杂核壳结构:富Cu核/B2_(s)壳以及B2_(c)核/FeMn壳,通过讨论分析发现形成的B2_(c)对纳米富Cu相的形成起到抑制作用,这种抑制作用随着Al元素的增加而变大;结合经验公式做出Al_(x)CuMnNiFe高熵合金富Cu相的屈服强度随时效时间的变化曲线,得到峰值屈服强度的时效时间和合金体系,可以为时效工艺提供参考.
High-entropy alloys with BCC and FCC coexisting structures usually have excellent comprehensive mechanical properties,and Al element can promote the transformation of Cu-containing high-entropy alloys from FCC structure to BCC structure to obtain the BCC and FCC coexisting structures.In order to illustrate the process of phase separation of high entropy alloys,a low-cost Al-TM transition group element high-entropy alloy is selected in this work.Based on the Chan-Hilliard equation and Allen-Cahn equation,a three-dimensional phase field model of Al_(x)CuMnNiFe high-entropy alloy is established,and the microscopic evolution of the nano-Cu-rich phase of Al_(x)CuMnNiFe high-entropy alloy(x=0.4,0.5,0.6,0.7)at 823 K isothermal aging is simulated.The results show that the Al_(x)CuMnNiFe high-entropy alloy generates two complex core-shell structures upon aging:Cu-rich core/B2_(s) shell and B2_(c) core/FeMn shell,and it is found through discussion and analysis that the formed B2_(c) plays an inhibitory role in the formation of the nano-Cu-rich phase,and that this inhibitory role becomes larger with the increase of Al element.Combining the empirical formula,the curve of yield strength of the Cu-rich phase varying with the aging time is obtained for the Al_(x)CuMnNiFe high-entropy alloy,and the overall yield strength of the high-entropy alloy has a rising-and-then-falling trend with the change of time,and the aging time of the peak yield strength and the alloy system are obtained from the change of the curve,so that the best alloy system and aging time of the high-entropy alloy can provide a reference for aging process.
作者
王凯乐
杨文奎
史新成
侯华
赵宇宏
Wang Kai-Le;Yang Wen-Kui;Shi Xin-Cheng;Hou Hua;Zhao Yu-Hong(School of Materials Science and Engineering,North University of China,Taiyuan 030051,China;Beijing Advanced Innovation Center for Materials Genome Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030025,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第7期313-327,共15页
Acta Physica Sinica
基金
国家自然科学基金(批准号:52074246,22008224,52275390,52205429,52201146)
国防基础科研项目(批准号:JCKY2020408B002,WDZC2022-12)
山西省重点研发项目(批准号:202102050201011,202202050201014)
山西省研究生创新项目(批准号:2021Y592)资助的课题.
关键词
相场法
高熵合金
富Cu相
弹性能
phase field method
high entropy alloy
Cu-rich phase
elastic energy
