Stabilized sub-grain and nano carbides-driven 1.2 GPa grade ultra-strong CrMnFeCoNi high-entropy alloy additively manufactured by laser powder bed fusion  

作　　者：Young-Kyun Kim Kee-Ahn Lee 

机构地区：[1]Department of Materials Science and Engineering,Inha University,Incheon 22212,Republic of Korea [2]Korea Institute of Materials Science(KIMS),Changwon 51508,Republic of Korea

出　　处：《Journal of Materials Science & Technology》2022年第22期8-22,共15页材料科学技术（英文版）

基　　金：This study supported by National Research Foundation of Korea(NRF)grant funded by the Korea government(MEST)(No.2019R1A2C1008904).

摘　　要：High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape components.Here,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was investigated.The as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content increases.When subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain scale.However,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation mechanism.In particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi HEAs.Furthermore,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging treatment.This work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关 键 词：Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism 

分 类 号：TG139[一般工业技术—材料科学与工程] TG665[金属学及工艺—合金]