摘要
研究温度对新型体心立方(BCC)基Fe_(3.5)Cr_(1.5)NiAl_(0.8)多组元合金(MCA)中有序椭圆状B2-NiAl纳米析出相的显微组织稳定性和力学性能的影响。采用XRD、EBSD、EPMA和TEM等检测方法对该多组元合金的显微组织和物相组成进行表征。结果表明,所设计的高含量椭圆状B2纳米析出相与BCC基体完全共格且能在1073 K高温下保持稳定,平均粒径为245.509~251.328 nm。铸态和热处理态(873 K≤T≤1073 K)合金具有独特的共格结构,这是由于低错配度的共格析出强化机制可使合金具有较高的屈服强度(809.2~1164.1 MPa)。随着热处理温度的进一步提高(1173 K≤T≤1273 K),B2纳米析出相的平均粒径逐渐粗化,载荷传递强化机制对其屈服强度提高起主要作用。
The effect of temperature on the microstructural stability and mechanical properties of ordered ellipsoidal B2-NiAl nanoprecipitates in a novel body-centered-cubic(BCC)-based Fe_(3.5)Cr_(1.5)NiAl_(0.8) multicomponent alloy(MCA)was investigated.XRD,EBSD,EPMA and TEM were used to characterize the microstructure and phase composition of this MCA.The results showed that the designed coherent microstructure with a high-content ellipsoidal B2 nanoprecipitates in BCC matrix could be maintained up to a high temperature of 1073 K with an average particle size of 245.509−251.328 nm.The unique coherent structure of the as-cast and heat-treated(873 K≤T≤1073 K)alloys could be designed to provide a high yield strength(809.2−1164.1 MPa)owing to the low-misfit coherent precipitation strengthening mechanism.When heat treatment temperature was further increased(1173 K≤T≤1273 K),the mean particle size of the B2 nanoprecipitates gradually coarsened,and the load transfer strengthening mechanism played a major role in improving the yield strength.
作者
张国家
王明亮
卢一平
王同敏
李廷举
Guo-jia ZHANG;Ming-liang WANG;Yi-ping LU;Tong-min WANG;Ting-ju LI(Liaoning Key Laboratory of Solidification Control and Digital Preparation Technology,School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;Liaoning Engineering Research Center of High-entropy Alloy Materials,School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)
基金
supported by the National Natural Science Foundation of China(Nos.52001051,U20A20278)
China Postdoctoral Science Foundation(No.2021T140082)
Liaoning Revitalization Talents Program,China(No.XLYC1807047)
Major Special Project of“Scientific and Technological Innovation 2025”in Ningbo,China(No.2019B10086)。
关键词
多组元合金
共格显微组织
显微组织演变
力学性能
强化机制
multicomponent alloy
coherent microstructure
microstructural evolution
mechanical properties
strengthening mechanism
作者简介
Corresponding author:Ming-liang WANG,Tel:+86-13206431096,E-mail:wml_8778@163.com;Corresponding author:Yi-ping LU,Tel:+86-411-84709400,E-mail:luyiping@dlut.edu.cn。
