钨镍(W-Ni)的焊接性能及工艺

Welding Properties and Technique of Wolfram and Nickel

异种金属的有效连接在高新技术领域具有实际意义,采用电阻点焊方法焊接稀有金属钨片和镍丝。用SEM,HRTEM表征焊接接头的组织形貌,用拉伸试验机测定焊接件的抗剪切力。采用如下焊接工艺:第一阶段:预压力是100 N,使钨镍良好接触;第二阶段:保持预压力不变,施以预热电流1.1 kA、400 ms,然后再施以焊接电流1.7 kA、400 ms;第三阶段:保持100 N的电极压力60 ms;最后,撤去电极压力。HRTEM结果表明:钨镍之间通过高温原子扩散形成置换固溶体而形成有效的连接,且在钨镍界面上没有新相形成。SEM结果表明焊接接头的镍丝没有翘头,且边缘没有严重压扁现象。经上述工艺得到的焊接接头的抗剪切力约为40 N,符合焊接件技术要求。

Effective welding of heterogeneity metals was of great pragmatic importance in modern hi-tech area.W plate and Ni thread were joined by using resistance spot-welding.SEM,HRTEM were used to characterize the microstructures of the welding-joint.The anti-shear forces of the welding-joint were measured with the tensile experimental machine.The optimized welding technique was as follows： the first stage pre-pressure 100 N;the second stage keeping pre-pressure,pre-heat current 1.1 kA,400 ms and then welding current 1.7 kA,400 ms;the third stage retaining pre-pressure for another 60 ms.The results of HRTEM showed that W and Ni were joined effectively through W and Ni atoms diffusion forming substitutional solid solution.There were no new phases or intermetallics between W and Ni on boundaries.SEM showed that the shape of the welding knot conformed to the technological requirements without severe deformation.The anti-shear force of the joint was about 40 N.