Ni中间层对铜/钢电子束焊接头组织与界面行为的影响  

Influence of Ni interlayer on microstructure and interface behavior of copper/steel electron beam welded joints

作　　者：赵健[1] 石磊[1] 陆煜 崔烺[1] 谢会起 吕竹文 王英[1] ZHAO Jian;SHI Lei;LU Yu;CUI Lang;XIE Huiqi;LÜZhuwen;WANG Ying(Ningbo Branch of Chinese Academy of Ordnance Science,Ningbo 315103,China)

机构地区：[1]中国兵器科学研究院宁波分院,浙江宁波315103

出　　处：《兵器材料科学与工程》2025年第2期126-132,共7页Ordnance Material Science and Engineering

基　　金：宁波市自然科学基金(2023J311,2023J313)。

摘　　要：针对铜/钢异种金属电子束焊接界面反应复杂、易产生渗透裂纹等问题,引入冷喷涂Ni中间层梯度过渡理念,研究了焊接热输入对焊缝特征区及两侧界面的显微组织、化学成分及元素扩散规律的影响。结果表明:焊缝区存在凝固裂纹,热影响区未见渗透裂纹,说明冷喷涂Ni中间层起到阻隔熔池中Cu/Fe元素互扩散的作用。随着焊接热输入的逐渐降低,焊缝区上部组织的生长趋势由胞状晶逐渐向粗大柱状枝晶转变;焊缝区下部观察到垂直于熔池底部生长的树枝晶显著增加,枝晶附近发现大量(Cu,Ni)基等轴枝晶聚积。钢侧与焊缝界面的组织生长规律由无成分过冷时的平面晶→胞状树枝晶→焊缝中心位置附近的等轴晶,焊缝两侧界面均存在成分连续变化的熔合过渡区,该区域可有效解决结合界面的失效问题。焊缝区平均显微硬度约为141.8HV_(0.3),硬度较高的区域为富铁相析出物,硬度较低的区域为富铜相基体。In order to solve the problems such as complex reaction at the interface of copper/steel dissimilar metal electron beam welding,the gradient transition concept of cold spraying Ni interlayer was introduced.The effects of welding heat input on the microstructure,chemical composition and element diffusion of the characteristic zone and the interface on both sides of the weld were studied.The results show that there are solidification cracks in the weld zone and no penetration cracks in the heat affected zone,indicating that the cold spraying Ni intermediate layer plays a role in blocking the mutual diffusion of Cu/Fe elements in the weld pool.With the decrease of welding heat input,the growth trend of the microstructure in the upper part of the weld zone gradually changes from cellular crystals to coarse columnar dendrites.The dendrites growing perpendicular to the bottom of the weld zone increase significantly,and a large amount of(Cu,Ni)base isaxed dendrites accumulated near the dendrites.The microstructure growth rule of the interface between steel side and weld is from plane crystal without subcooling to cellular dendritic crystal to equiaemic crystal near the weld center.There is a fusion transition zone with continuous composition change at both sides of the weld interface,which can effectively solve the failure problem of the bonding interface.The average microhardness of the weld zone is about 141.8HV_(0.3),the region with higher hardness is Fe⁃rich precipitates,and the region with lower hardness is copper⁃rich matrix.

关 键 词：电子束焊接 异种金属焊接 冷喷涂中间层 显微组织 元素扩散 

分 类 号：TG401[金属学及工艺—焊接] TG456.3