Mechanical property and cellular structure of an additive manufactured FeCoNiCrMo_(0.2) high-entropy alloy at high-velocity deformation  

作　　者：Wenshu Li YiYu Huang ZhongHao Xie Haoyu Chen Weihua Li Bin Liu Bingfeng Wang 

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]School of Materials Science and Engineering,Central South University,Changsha 410083,China

出　　处：《Journal of Materials Science & Technology》2023年第8期156-166,共11页材料科学技术（英文版）

基　　金：The present work was financially supported by the National Natural Science of China(No.52020105013);by the State Key Laboratory of Powder Metallurgy(No.62102172).

摘　　要：The microstructural modification for cellular structures can achieve the improvement of dynamic me-chanical properties of a selective laser melted FeCoNiCrMo_(0.2)high-entropy alloy(SLM-FeCoNiCrMo_(0.2)HEA)and can expand its promising applications in the field of high-velocity deformation.In this work,FeCoNiCrMo_(0.2)HEAs with cellular structures in different sizes were produced by selective laser melt-ing(SLM)with different process parameters.The dynamic mechanical properties and microstructure of the SLM-FeCoNiCrMo_(0.2)HEA were studied.The dynamic mechanical properties of the SLM-FeCoNiCrMo_(0.2)HEA increased with decrease of average size of cellular structures,and the values of them were sensitive to strain rates.The energy absorption,compressive strength and yield strength of the SLM-FeCoNiCrMo_(0.2)HEAs reached 315.6 MJ/m^(3),2.2 GPa and 775.6 MPa,respectively at a strain rate of 2,420 s^(−1),under the process parameters of laser power and scanning speed of 330 W and 800 mm/s,respectively,where the corresponding average size of cellular structures in the HEAs was 483.6 nm.The value of strain-hardening rate of the SLM-FeCoNiCrMo_(0.2)HEA was about 5.1 GPa at a strain level of 0.1,which was much higher than that of the powder-metallurgy FeCoNiCrMo_(0.2)HEA.The cellular structure was formed inside the molten pool with segregation of Mo on the boundary.Deformation localization appeared in the cellular structures,forming several deformation bands after high strain-rate deformation.The elemental segre-gation strengthening and dislocation strengthening are considered to be the main strengthening mecha-nisms in SLM-FeCoNiCrMo_(0.2)HEA.

关 键 词：FeNiCr-based HEA Additive manufacturing Mechanical property Cellular structure Strengthening mechanisms 

分 类 号：TG139[一般工业技术—材料科学与工程]