文献类型：期刊文献

英文题名：Effects of post annealing on the microstructure, precipitation behavior, and mechanical property of a (CoCrNi)94Al3Ti3 medium-entropy alloy fabricated by laser powder bed fusion

作者：Li, Zhuang[1];Zhao, Pengcheng[1];Lu, Tiwen[1];Feng, Kai[2];Tong, Yonggang[3];Sun, Binhan[1];Yao, Ning[1];Xie, Yu[1];Han, Bolun[2];Zhang, Xiancheng[1];Tu, Shantung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[2]Shanghai Jiao Tong Univ, Sch Mat Sci & Engn, Shanghai Key Lab Mat Laser Proc & Modificat, Shanghai 200240, Peoples R China;[3]Changsha Univ Sci & Technol, Coll Automobile & Mech Engn, Changsha 410114, Peoples R China

年份：2023

卷号：135

起止页码：142

外文期刊名：JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

收录：;EI(收录号：20223412613125);WOS:【SCI-EXPANDED(收录号:WOS:000864072300004)】；

基金：Acknowledgments This work was financially supported by the National Natural Science Foundation of China (nos. 52105144 and 51725503) , the Shanghai Super Postdoctoral Incentive Plan (no. 2020134) and the China Postdoctoral Science Foundation (no. 2021M701201) .

语种：英文

外文关键词：Medium-entropy alloy; Additive manufacturing; Heat treatment; Strengthening mechanism; Microstructural evolution

摘要：The additive manufacturing of multi-principal element alloys has remarkable potential for industrial ap-plications. In this study, a (CoCrNi)(94)Al3Ti3 medium-entropy alloy (MEA) with adequate strength-ductility synergy was prepared via laser powder bed fusion. The microstructural evolution, mechanical property, and deformation mechanisms of the MEA were investigated after post annealing for a short period (0.5 h) at a temperature range of 773-1373 K using various microstructural characterization techniques and quantitative analysis. The static recrystallization temperature of the (CoCrNi)(94)Al3Ti3 MEA ranged from 973 to 1073 K. The average grain size first decreased and then increased, while the dislocation density persistently decreased and texture gradually weakened with increasing annealing temperature. Cr-rich similar to-phase precipitates formed after 1073 K and then gradually dissolved at 1373 K, while Ni, Al, and Ti elements were aggregated to form a small amount of fine L1 2 coherent precipitates with an aver-age diameter of approximately 70 nm at 1373 K. The evolution of the dislocation density, grain size, and precipitates significantly influenced the propensity of deformation twins and stacking faults, which consequently affected the strain hardening behavior and mechanical properties. The quantitative calculation of strengthening mechanisms showed that dislocation strengthening played a dominant role at annealing temperatures below 1073 K, and it significantly weakened at 1373 K. Precipitation and grain boundary strengthening both markedly increased owing to the formation of precipitation particles and recrystallization-induced grain refinement after annealing at 1073 K.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.