基于高熵合金中间层的Q235钢/6061铝合金电阻点焊接头的组织与性能  

Microstructure and properties of Q235 steel/6061 aluminum alloy resistance spot welding joint based on high-entropy alloy interlayer

作　　者：蒋淑英[1] 蔡畅 赵明[1] 黄万群[1] JIANG Shuying;CAI Chang;ZHAO Ming;HUANG Wanqun(China University of Petroleum(Huadong),Qingdao,266580,China)

机构地区：[1]中国石油大学(华东),青岛266580

出　　处：《焊接学报》2023年第7期71-78,I0007,共9页Transactions of The China Welding Institution

基　　金：山东省自然科学基金面上资助项目(ZR2020ME013)。

摘　　要：钢和铝形成的复合结构,可以使铝的低密度、高导热性、良好的耐腐蚀性能与钢的高强度、高韧性、低成本性结合起来,既能充分发挥两种材料的性能优势,又具有良好的经济效益.由于钢和铝的物理和化学性能差异较大、接头中易产生脆性金属间化合物而难以实现可靠的连接.将Fe_(0.2)CoCrMnNiAl_(0.2)高熵合金作为中间层进行了Q235钢/6061铝合金异种金属的电阻点焊研究,利用高熵合金的超级固溶性改善钢/铝异种金属的焊接质量.结果表明,采用Fe_(0.2)CoCrMnNiAl_(0.2)高熵合金作为中间层时,接头截面中钢侧和铝侧均有半椭圆形状的熔核,熔核成形美观,无明显的宏观裂纹和气孔等焊接缺陷,熔核内部组织均由面心立方的固溶体相组成,接头的平均最大拉剪力达到1913 N,比钢/铝直接电阻点焊接头提高了130%,断裂发生在铝合金侧熔核处,铝合金熔核在拉剪力的作用下被撕脱并留在高熵合金表面,呈现出“纽扣状”破坏特征.创新点:利用高熵合金的超级固溶特性,将高熵合金作为中间层应用到钢-铝异种金属的电阻点焊中,设计出了能够可靠连接钢-铝异种金属的高熵合金中间层材料,制备出了成形美观、无焊接缺陷的高质量钢/铝电阻点焊接头.The composite structure formed by steel and aluminum has a combination advantages of aluminums such as low density,high thermal conductivity,and excellent corrosion resistance,and hightlights of steels like high strength,toughness and low cost.The structure gives full play to the high performance of both materials and exhibits superior economic efficiency.However,it is difficult to obtain a reliable welding joint between the two materials due to the giant difference in the physical and chemical properties of them,which tend to generate brittle intermetallic compounds in the joint.In this paper,Fe_(0.2)CoCrMnNiAl_(0.2)high-entropy alloy was applied as an interlayer to weld the steel/aluminum metals,utilizing the super solid solubility of the high-entropy alloy as a boost to the welding quality.The results show that when the interlayer was used,semi-elliptical nuggets showed up on the steel and aluminum sides of the joint section.The joint was neatly formed and without obvious macroscopic cracks,pores or other welding defects.The phase structures of the two nuggets were facecentered cubic solid solutions.The maximum tensile shear force of the joint reached 1913 N,which was 130%higher than that of the steel/aluminum direct resistance spot welded joint.Fracture occured at the aluminum alloy nugget,which was torn off by the tensile shear force and left on the surface of the highentropy alloy,exhibiting a“button-like”fracture.Highlights:Utilizing the super solution characteristics of high-entropy alloy,a high-entropy alloy intermediate layer material is designed to enable the reliable resistance spot welding of steel/aluminum dissimilar metals.High-quality welding joint was achieved,which was neatly shaped and free of welding defects.

关 键 词：Q235钢 6061铝合金 高熵合金中间层 电阻点焊 

分 类 号：TG422[金属学及工艺—焊接]