Displacive transformation as pathway to prevent micro-cracks induced by thermal stress in additively manufactured strong and ductile high-entropy alloys

作     者：Rui-di LI Peng-da NIU Tie-chui YUAN Zhi-ming LI 李瑞迪;牛朋达;袁铁锤;李志明

作者机构：State Key Laboratory of Powder MetallurgyCentral South UniversityChangsha 410083China School of Materials Science and EngineeringCentral South UniversityChangsha 410083China 

基　　金：financial support of the National Natural Science Foundation of China (51505166,51971248) the Huxiang Young Talents Project (2018RS3007,2019RS1001) the Innovation-Driven Project of Central South University,China (2020CX023) Science and Technology Project of Hunan Province (2020GK2031) 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2021年第31卷第4期

页      码：1059-1073页

摘      要：The micro-cracking behaviors of two high-entropy alloys(HEAs) of the FeMnCoCrNi family prepared by selective laser melting were systematically studied. Residual stresses were also analyzed by X-ray diffraction technique. Results show that the equiatomic FeMnCoCrNi HEAs with a relatively stable single-phase face-centered cubic(FCC) structure suffered from micro-cracking with residual tensile stress after laser melting. In contrast, the metastable non-equiatomic Fe MnCoCr HEAs with reduced stacking fault energy are free of micro-cracks with residual compressive stress at various volumetric energy densities(VEDs). The displacive transformation from the FCC matrix to the hexagonal close-packed(HCP) phase during cooling prevents the micro-cracking via consuming thermal stress related internal energy. Further, the displacive transformation during tensile deformation contributes to the higher strength and ductility of the metastable dual-phase HEA compared to that of the stable single-phase HEA. These findings provide useful guidance for the design of strong, ductile, and crack-free alloys for additive manufacturing by tuning phase stability.

主 题 词：selective laser melting high-entropy alloys phase transformation micro-cracking residual stress 

学科分类：0806[工学-电气类] 08[工学] 0818[工学-交通运输类] 0815[工学-矿业类] 0805[工学-能源动力学] 080502[080502] 0813[工学-化工与制药类] 0703[理学-化学类] 0814[工学-地质类] 0702[理学-物理学类] 

核心收录：

D　O　I：10.1016/S1003-6326(21)65561-9

馆 藏 号：203102860...