Microstructure evolution and strengthening mechanism of CoCrFeMnNi HEA/Zr-3 brazed joints reinforced by fine-grained BCC HEA and HCP Zr  

作　　者：Xiaoguo Song Nan Jiang Hong Bian Hyoung Seop Kim Danyang Lin Weimin Long Sujuan Zhong Lianhui Jia Daijun Hu 

机构地区：[1]State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin,150001,China [2]Shandong Institute of Shipbuilding Technology,Weihai,264209,China [3]Graduate Institute of Ferrous Technology,POSTECH(Pohang University of Science and Technology),Pohang,790794,South Korea [4]State Key Laboratory of Advanced Brazing Filler Metals and Technology,Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.,Zhengzhou,450001,China [5]China Railway Engineering Equipment Group Co.,Ltd.,Zhengzhou,450016,China [6]Sichuan Aerospace Long March Equipment Manufacturing Co.,Ltd.,Chengdu,610100,China

出　　处：《Journal of Materials Science & Technology》2024年第18期32-47,共16页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.52275321 and 52205348);the Shandong Natural Science Foundation(No.ZR2023JQ021);the Taishan Scholars Foundation of Shandong Province(No.tsqn201812128);the Innovation Scientists and Technicians Troop Projects of Henan Province(No.204200510031);the Heilongjiang Touyan Innovation Team Program(No.HITTY-20190013);supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(Nos.NRF-2021R1A2C3006662 and NRF-2022R1A5A1030054).

摘　　要：In the pursuit of manufacturing intricate components for the nuclear industry,we developed a novel Zr_(63.2)Cu_(36.8)(wt.%)alloy via vacuum melting for brazing applications involving equiatomic high-entropy alloys(HEA)of CoCrFeMnNi and zircaloy(Zr-3).We systematically investigated the influence of various brazing parameters on microstructure evolution and shear properties.Furthermore,we established a com-prehensive understanding of the relationship between the lattice structure of interfacial products,residual stress,and fracture behavior in HEA/Zr-Cu/Zr-3 joints.Our findings revealed that under specific conditions(1010℃for 10 min),the reaction products in HEA/Zr-Cu/Zr-3 joints consisted of lamellar HEAP/lamellar Zr(Cr,Mn)_(2),granular(Zr,Cu)/Zr_(2)(Cu,Ni,Co,Fe),bulk Zr(Cr,Mn)_(2),and Zrss.With increasing temperature and prolonged holding time,the layered HEAP and Zr(Cr,Mn)_(2)phases adjacent to the HEA substrates thick-ened,while the relative amounts of Zr_(2)(Cu,Ni,Co,Fe)decreased,with a remarkable increase in ductile Zrss.Growth kinetics analysis of the reaction layer and EBSD analysis indicated that the HEAP phases exhibited a lower growth rate compared to the Zr(Cr,Mn)_(2)layer during brazing,and both phases exhibited random grain orientations.Particularly noteworthy was the precipitation of(Zr,Cu)within the layered Zr(Cr,Mn)_(2),which increased and coarsened with higher temperatures and extended durations.Finite element analysis and TEM analysis revealed higher residual stresses at the non-coherent Zr(Cr,Mn)_(2)/HEAP interface with a lattice mismatch of 40.6%.The body-centered cubic(BCC)structural HEAP,composed of fine grains,effectively mitigated the concentrated residual stresses due to its superior plasticity.Moreover,micro-nanoscale close-packed hexagonal(HCP)precipitates(Zr,Cu)were distributed within the brittle Zr(Cr,Mn)_(2)phases,contributing to the overall strength improvement of the joints.Consequently,high-quality HEA/Zr-3 joints were achieved,featuring a maximum strength of 172.1 MPa,equivalent

关 键 词：High entropy-alloys Zr alloys Microstructure evolution Mechanical property Growth kinetics Residual stress 

分 类 号：TG139[一般工业技术—材料科学与工程]