微细丝与异质材料多股导线平行电极电阻钎焊装置设计及焊接工艺研究

目的 开发用于微细直径丝材与不等直径异质多股线精密连接的装置，并对其进行优化设计。方法 采用直径为0.2 mm的镍丝与不等直径铜质多股线为焊材，采用石墨电极，设计了以上电极为凸台、下电极为凹槽的方案，但考虑到凸台电极容易发生损耗，将上电极优化为平行电极，并结合装置特点设计了专用工装夹具。在此基础上进行焊接试验;分别选用直接微电阻钎焊工艺与平行电极微电阻钎焊工艺对镍丝与铜质多股线进行焊接试验，对比研究了先上电极优化后微电阻钎焊、先压方后微电阻钎焊、直接微电阻钎焊、平行电极微电阻钎焊工艺所得焊接接头的成形情况，探究不同工艺与焊接参数对接头质量的影响机制，并获得最优工艺方案;对不同工艺及焊接参数下所得的焊接接头进行拉剪力测试与微观组织分析，对不同条件下接头的拉剪力与微观组织进行分析比较，并对拉剪性能较好的平行电极微电阻钎焊接头进行振动测试，研究其抗振性能。结果 采用先上电极优化后微电阻钎焊工艺得到的焊接接头的平均拉剪力为21.04 N;采用先压方后微电阻钎焊工艺得到的焊接接头的平均拉剪力为15.04 N;采用直接微电阻钎焊工艺得到的焊接接头的最大拉剪力为22.3 N，其钎料并未完全包裹高温导线，成形差;采用平行电极微电阻钎焊工艺得到的焊接接头的平均拉剪力为24.8 N，其接头连接稳定，最大直径均不超过0.8 mm，且抗振性能良好。结论 设计并优化得到的平行上电极能够有效减少电极损耗，通过比较各工艺接头可知，先压方后平行电极微电阻钎焊为最佳的焊接方案，焊点直径稳定，接头质量良好，可以实现传感器引脚线与多股高温导线的高质量、精密、可靠焊接。

Device Design and Welding Technology of Parallel Electrode Resistance Brazing for Micro Wire and Heterogeneous Material Multi Wire

The work aims to develop and optimize devices for precise connection of micro wire direct wire and unequal diameter heterogeneous multi-strand wire. The nickel wire with a diameter of 0.2 mm and the copper multi-strand wire with unequal diameter were used as welding materials, and the graphite electrode was used. The upper electrode was designed into a convex platform and the lower electrode was designed into a groove. However, considering that the convex platform electrode was prone to loss, the upper electrode was optimized as a parallel electrode, and a special fixture was designed according to the characteristics of the device. On this basis, welding experiments were carried out; the welding experiments of nickel wire and copper multi-strand wire were carried out by direct micro-resistance brazing process and parallel electrode micro-resistance brazing process respectively. The forming conditions of welded joints obtained by optimizing the upper electrode, pressing square before welding, direct micro-resistance brazing and parallel electrode micro-resistance brazing process were compared. The influence mechanism of different processes and welding parameters on the quality of joints was explored, and the optimal process scheme was obtained. The tensile shear test and microstructure analysis of the welded joints under different processes and parameters were carried out. The tensile shear force and microstructure of the joints under different conditions were analyzed and compared. The vibration test of the parallel electrode micro-resistance brazing joint with good tensile shear performance was carried out to study its anti-vibration performance. The average tensile shear force of the welded joint obtained by the upper electrode optimized micro-resistance brazing process was 21.04 N; that obtained by the process of micro-resistance brazing after pressing square was 15.04 N; the maximum tensile shear force of the welded joint obtained by the direct micro-resistance brazing process was 22.3 N, and the solder did not completely wrap the high-temperature wire, and the forming was poor. The average tensile shear force of the welded joint obtained by the parallel electrode micro-resistance brazing process was 24.8 N, the joint connection was stable, the maximum size diameter did not exceed 0.8 mm, and the vibration resistance was good. The parallel upper electrode designed and optimized can effectively reduce the electrode loss. By comparing the joint properties of various processes, it can be seen that the scheme of parallel electrode micro-resistance brazing after pressing the square is the best. It has stable solder joint diameter and good joint quality. It can achieve high-quality, precise, and reliable welding of sensor pin wires and multi-strand high-temperature wires.