采用Cu-5Ni(质量分数,%)合金箔为中间层,在加压15MPa、连接温度1120℃、保温10~360min的工艺条件下对纯钨/316L不锈钢进行瞬间液相扩散连接。利用OM、SEM、EDS和电子万能试验机等研究接头的微观组织、成分分布、力学性能及断口特征。结果表明:保温10和30min对应的接头组织由分界明显的富铁层和富铜层两层构成;保温时间增至180min时,接头组织中的富铜层变薄、变分散,而富铁层则变厚、且局部和不锈钢奥氏体晶粒粘接;当保温时间达到360min后,接头区和不锈钢母材较好地实现了组织与成分均匀化,钨母材中则形成2~3μm厚的Cr、Fe元素扩散带,接头抗剪强度达到213MPa,断裂失效主要发生在钨母材中。
Transient liquid phase bonding between tungsten (W) and stainless steel 316L using a Cu-5Ni (mass fraction, %) alloy interlayer was carried out in vacuum at 1 120 ℃ for 10-360 min with a pressure of 15 MPa. The microstructures, composition distribution and fracture characteristics of the joints were studied by OM, SEM, EDS and their mechanical properties were tested by shear experiments. The results show that the microstructures of the joints holding for 10 and 30 min consist of Fe-rich layer and Cu-rich layers with clear boundaries. When the holding time increases to 180 min, Cu-rich layer becomes thin and disperse, while Fe-rich layer becomes thick and part of it bonds to the stainless steel austenite grain. When the holding time reaches 360 min, the microstructure and composition of bonding zone become homogenous, and 2-3 μm-thick Cr, Fe elements diffuse band also forms in the tungsten matrix. The average shear strength of joints holding for 360 min reaches 213 MPa, and the fracture failure occurs mainly in the tungsten matrix.