文献类型：期刊文献

英文题名：Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior

作者：Zhang, Jianrui[1];Yan, Yabin[1];Li, Bo[1,2]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[2]Shanghai Collaborat Innovat Ctr High End Equipment, Shanghai 200237, Peoples R China

年份：2022

卷号：15

期号：23

外文期刊名：MATERIALS

收录：;EI(收录号：20225013242196);WOS:【SCI-EXPANDED(收录号:WOS:000896157800001)】；

基金：This research was funded by the Fellowship of China Postdoctoral Science Foundation, grant number 2021TQ0105; National Natural Science Foundation of China, grant number 52205155; and Natural Science Foundation of Shanghai, China, grant number 20ZR1414000.

语种：英文

外文关键词：selective laser melting; high-entropy alloys; CoCrFeNiMn; process optimization; microscale mechanical properties; fatigue; nano-twins

摘要：The equiatomic CoCrFeNiMn high-entropy alloy (HEA) possesses excellent properties including exceptional strength-ductility synergy, high corrosion resistance, and good thermal stability. Selective laser melting (SLM) additive manufacturing facilitates the convenient fabrication of the CoCrFeNiMn HEA parts with complex geometries. Here, the SLM process optimization was conducted to achieve a high relative density of as-built CoCrFeNiMn HEA bulks. The mechanisms of process-induced defects and process control were elucidated. The microscale mechanical behaviors were analyzed through in situ scanning electron microscopy observation during the compression tests on micro-pillars of the as-built HEA. The stress-strain characteristics by repeated slip and mechanism of "dislocation avalanche" during the compression of micro-pillars were discussed. The high-cycle fatigue tests of the as-built HEA were performed. It was found that a large number of nano-twins were induced by the fatigue, causing a non-negligible cycle softening phenomenon. The effects of promoted ductility due to the fatigue-induced nano-twins were illustrated. This work has some significance for the engineering application of the SLM additively manufactured CoCrFeNiMn HEA parts.