Progress in weldability research of high entropy alloys  

作　　者：刘爱国 王超 Liu Aiguo;Wang Chao(School of Materials Science and Engineering,Shenyang Ligong University,Shenyang 110159,China)

机构地区：[1]School of Materials Science and Engineering,Shenyang Ligong University,Shenyang 110159,China

出　　处：《China Welding》2023年第1期53-62,共10页中国焊接（英文版）

摘　　要：High entropy alloys usually show good weldability.The weldability problems of high entropy alloys are segregation,cracks,and hardening or softening of weld,etc.When an Al_(x)CoCrFeNi alloy is welded,Al and Ni will segregate to the interdendritic region in the weld,but the degree of segregation is less than that of the base metal.When an Al_(x)CoCrCu_(x)FeNi alloy or a CoCrCu_(x)FeNi alloy is welded,Cu tends to segregate to the interdendritic region in the weld.Increasing the cooling rate of the welding process,such as with laser welding,is conducive to reducing the segregation in the weld.The segregation in the weld and the heat affected zone,especially the segregation of Cu,will lead to the generation of hot cracks.Hot cracking is the main form of cracking in high entropy alloys joints.Welding will lead to changes in the hardness of the weld.The main factors affecting the hardness change are the grain sizes and the precipitations.With laser welding,if the base metal is cold rolled,the hardness of the weld will decrease.If the base metal is hot rolled and annealed or cast,the hardness of the weld will increase.With TIG welding,the hardness of the weld is usually lower than that of the base metal,unless the grain of the base metal is particularly coarse before welding.With friction stir welding,recrystallization and grain refinement occur in the stir zone,and the hardness of the stir zone will be significantly improved no matter the original base metal is cold rolled or cast.

关 键 词：high entropy alloys WELDABILITY SEGREGATION CRACK HARDNESS 

分 类 号：TG139[一般工业技术—材料科学与工程] TG406[金属学及工艺—合金]