焊接电压对绝缘铜线微电阻热压焊接头的影响

采用微电阻热压焊工艺来焊接耐高温微细绝缘铜线，研究了不同焊接电压下接头的外观形貌、截面微观组织、拉断力和形成过程. 结果表明，当焊接时间为20 ms、电极压力为12 N、焊接电压大于2.05 V时，该工艺可在一个输出脉冲内完成绝缘铜线的除漆和焊接，无需预先除漆. 随着焊接电压的增加，接头长度基本不发生变化，接头宽度和拉断力一直增大；接头失效形式依次表现为界面剥离、前端断裂和中部断裂. 接头的演变过程包括预压塑性变形、接头弱连接、热辅助下的压陷、接头强连接和熔融金属挤出5个阶段.

Effect of welding voltage on resistance thermocompression welded micro-joints of insulated copper wire

The resistance thermocompression micro-welding process was used to weld the high temperature resistant fine insulated copper wires. The formation process of the joints under various welding voltages, formation of weld, cross-sectional microstructure and breaking force were studied. The results show that when the welding time is 20 ms, the electrode pressure is 12 N, and the welding voltage is greater than 2.05 V, the paint removal and welding of the insulated copper wire can be completed within one output pulse without prior paint removal. Joint width and joint tensile force gradually increase with the increase of welding voltage while the length of the joint remains unchanged. The failure modes of the joints are in turn joint interface separation, joint front section fracture and joint middle fracture. The evolution of the joint consists of five stages: pre-compression plastic deformation, weak bonding joint, thermally assisted indentation, strong bonding joint and melt extrusion.