基于高熵合金中间层的铜/钢TIG焊接头组织与性能  

Microstructure and properties of copper/steel TIG welded joint based on high-entropy alloy interlayer

作　　者：蒋淑英 张军利 赵明 JIANG Shuying;ZHANG Junli;ZHAO Ming(College of Materials Science and Engineering in China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)材料科学与工程学院,山东青岛266580

出　　处：《中国石油大学学报（自然科学版）》2023年第6期154-161,共8页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：山东省自然科学基金面上项目(ZR2020ME013)。

摘　　要：铜/钢复合结构不仅能够满足不同环境对材料性能的要求,还可减少铜材的消耗,将大大降低构件的成本;但铜与钢之间物化性能差异较大,其中极差的相溶性会导致焊后出现液相分离或缺陷。基于焊缝金属固溶-高熵化思路,设计Fe_(5)Co_(30)Cr_(30)Ni_(30)Cu_(5)高熵合金作为中间层,对T2紫铜和Q235钢进行TIG焊接,并对中间层及接头的组织与性能进行分析。结果表明:Fe_(5)Co_(30)Cr_(30)Ni_(30)Cu_(5)高熵合金为单相FCC固溶体结构,具有良好的强度和塑韧性;采用该中间层材料,利用TIG焊方法可实现T2紫铜和Q235钢的可靠连接,焊缝成形良好且无气孔、裂纹等缺陷;焊缝区组织为单相FCC固溶体结构,具有显著的高熵化特征;焊接接头平均抗拉强度为225 MPa,达到铜母材强度的91%,平均断后延伸率达到44%;接头断裂发生在紫铜侧热影响区,且断口表面呈现有大量的韧窝结构,具有显著的韧性断裂特征。The copper/steel composite structure can not only meet the performance requirements of different environments,but also can reduce the consumption of copper materials and greatly reduce the cost of components.However,the physical and chemical properties of copper and steel are quite different,and the extremely poor miscibility will lead to liquid phase separation or defects after welding.Based on the idea of solid solution-high entropy of weld metal,Fe_(5)Co_(30)Cr_(30)Ni_(30)Cu_(5) high-entropy alloy was designed as the intermediate layer to carry out TIG welding of T2 copper and Q235 steel,and the micro-structure and properties of the intermediate layer and welded joint were analyzed.The results show that,Fe_(5)Co_(30)Cr_(30)Ni_(30)Cu_(5) high-entropy alloy is a single-phase FCC solid solution with good strength and plastic toughness.Using the high-entropy alloy as the intermediate layer material,the reliable connection between T2 copper and Q235 steel can be achieved by the TIG welding method.The welded joint is formed well,without pores,cracks and other defects.The weld microstructure is a sim-ple solid solution with FCC structure,which has a remarkable high entropy characteristic.The average tensile strength value of the welded joint is 225 MPa,reaching 91%of the strength of T2 copper,and the extension ratio after fracture can reach 44%.The fracture of joint occurs in the heat-affected zone on the copper side.There are a large number of dimples on the fracture surface,showing the significant characteristic of ductile fracture.

关 键 词：T2紫铜 Q235钢 TIG焊 高熵合金中间层 组织 性能 

分 类 号：TG422[金属学及工艺—焊接]