Evolution of helium bubbles in FeCoNiCr-based high-entropy alloys containing γ′ nanoprecipitates  

作　　者：冯婷 蒋胜明 胡潇天 张子骏 黄子敬 董士刚 张建 Ting Feng;Sheng-Ming Jiang;Xiao-Tian Hu;Zi-Jun Zhang;Zi-Jing Huang;Shi-Gang Dong;Jian Zhang(College of Energy,Xiamen University,Xiamen 361005,China)

机构地区：[1]College of Energy,Xiamen University,Xiamen 361005,China16

出　　处：《Chinese Physics B》2024年第7期491-500,共10页中国物理B（英文版）

基　　金：Project support provided by the National Natural Science Foundation of China(Grant No.12075200);the National Key Research and Development Program of China(Grant No.2022YFB3706004)。

摘　　要：A series of high-entropy alloys(HEAs) containing nanoprecipitates of varying sizes is successfully prepared by a non-consuming vacuum arc melting method.In order to study the irradiation evolution of helium bubbles in the FeCoNiCrbased HE As with γ' precipitates,these samples are irradiated by 100-keV helium ions with a fluence of 5 × 10^(20) ions/m^(2) at 293 K and 673 K,respectively.And the samples irradiated at room temperature are annealed at different temperatures to examine the diffusion behavior of helium bubbles.Transmission electron microscope(TEM) is employed to characterize the structural morphology of precipitated nanoparticles and the evolution of helium bubbles.Experimental results reveal that nanosized,spherical,dispersed,coherent,and ordered L1_(2)-type Ni_(3)Ti γ' precipitations are introduced into FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs by means of ageing treatments at temperatures between 1073 K and 1123 K.Under the ageing treatment conditions adopted in this work,γ' nanoparticles are precipitated in FeCoNiCr(Ni_(3)Ti)_(0.1) HE As,with average diameters of 15.80 nm,37.09 nm,and 62.50 nm,respectively.The average sizes of helium bubbles observed in samples after 673-K irradiation are 1.46 nm,1.65 nm,and 1.58 nm,respectively.The improvement in the irradiation resistance of FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs is evidenced by the diminution in bubbles size.Furthermore,the FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs containing γ' precipitates of 15.8 nm exhibits the minimum size and density of helium bubbles,which can be ascribed to the considerable helium trapping effects of heterogeneous coherent phase boundaries.Subsequently,annealing experiments conducted after 293-K irradiation indicate that HEAs containing precipitated phases exhibits smaller apparent activation energy(E_(a)) for helium bubbles,resulting in larger helium bubble size.This study provides guidance for improving the irradiation resistance of L1_(2)-strengthened high-entropy alloy.

关 键 词：high-entropy alloys irradiation resistance coherent precipitates helium bubbles 

分 类 号：TG139[一般工业技术—材料科学与工程] TL34[金属学及工艺—合金]