钨/铜异种金属钎焊工艺及接头组织性能研究OA

Materials exhibiting significant differences in the physical properties of tungsten and copper pose a substantial technical challenge for achieving reliable metallurgical bonding.Process research was conducted using vacuum brazing combined with a novel Ti-Zr based amorphous filler metal.The influence of brazing temperature on joint microstructure,element distribution,microhardness,and shear strength was comprehensively investigated.The results indicate that at lower brazing temperatures(840～880℃),the welds exhibited pronounced porosity and incomplete fusion.As the temperature increased to 900℃,the weld seam exhibited excellent formation quality;internal porosity was effectively suppressed,microstructural uniformity was significantly enhanced,and a continuous interfacial diffusion layer formed across the joint.The diffusion layer thickness measured approximately 20 µm on the copper side and approximately 10 µm on the tungsten side.The microhardness of the brazed joint exhibits a distinct gradient distribution,increasing progressively from the tungsten substrate to the copper substrate and peaking at 404.8HV0.1 in the interfacial middle layer at a brazing temperature of 900℃.When the brazing temperature is 900℃and the holding time is 30 minutes,ideal metallurgical bonding can be achieved.The interface layers exhibit a continuous and dense microstructure,free from typical defects such as porosity or cracks.The average shear strength of the joint reaches 152.9 MPa.The fracture morphology of the joint and EDS analysis reveal that the fracture surface of this joint presents a mixed fracture mode characterized by quasi-cleavage facets interspersed with ductile dimples and tear ridges.The fracture occurs at the transition zone between tungsten and the brazing filler.