TC1 电阻微焊接接头显微组织及力学性能

目的 研究不同工艺参数（焊接电流、焊接时间）对金属箔材精密电阻微焊接头机械性能的影响。方法 采用电阻微焊接技术对0.05 mm 厚的TC1 箔材进行点焊连接试验，通过拉伸-剪切试验对焊接接头进行力学性能检测，利用硬度网格法结合金相观察，对焊接不同区域进行有效预测。结果 当焊接电流为400 A时，焊核直径随着焊接时间的增加而明显增大，而采用更高的焊接电流时，焊接时间对焊接直径没有显著影响。焊点接头的剪切力随着电流的增大而增大；在所有参数条件下，过长焊接时间都造成了焊点接头剪切力不同程度的减小。此外，由于微观组织的变化，不同焊接区域显现出不同硬度值，其中焊核硬度>母材硬度>热影响区硬度。结论 焊接电流对TC1 电阻微焊接接头力学性能影响较大；硬度网格法可以有效预测焊接不同区域。

Prediction of Microstructure of TC1 of Micro Spot Welding Joint Based on Hardness Map and the Analysis of Mechanical Properties

The work aims to investigate the influence of different welding parameters (welding current, welding time) on mechanical properties of joint. The 0.05 mm thick TC1 foils were welded with the technology of precise micro resistance welding. The mechanical properties were evaluated by tensile-shear test and the different regions were defined and predicted by hardness map coupled with microstructure observation. The welding time has a great influence on the diameter of 400 A, but has little effect on other current parameters. When the other welding parameters remained constant, the shearing force of joint increased with the increase of the current, under all the parameters. Too long welding time will result in the reduction of shear force in different degree. The welding current plays the major role on mechanical performance of welded joint after small scale resistance spot welding, and hardness map can accurately predict the different regions of the joint.