The so-called hairpin winding technology, which is specially tailored to electrical traction components, deploys rectangular plug-in copper wires in the stator. The fusion welding of the adjacent wire ends is associated with challenges due to the high thermal conductivity as well as the porosity formation of the copper. During this study, the electron beam (EB) welding of electrolytic tough pitch (ETP) and oxygen-free electronic grade (OFE) copper connectors was investigated. Subsequently, the specimens underwent X-ray computed tomography (CT) and metallographic examinations to characterize the joints. It was discovered that the residual oxygen content of the base material is responsible for the pore formation. With only a very low level of oxygen content in the copper, a porosity- and spatter-free welding can be reproducibly realized using the robust EB welding technology, especially for copper materials. By optimizing the parameters accordingly, joints exhibiting a low level of porosity were achieved even in the case of the alloy containing a high amount of residual oxygen. Beyond this, detailed analyses in terms of pore distribution were carried out and a good correlation between technological parameters and welding results was determined.

所谓的发夹式绕组技术，专为电力牵引部件量身定做，在定子中部署矩形插入式铜线。由于铜的高导热性和孔隙率，相邻线端的熔焊面临挑战。在这项研究中，研究了电解韧沥青 (ETP) 和无氧电子级 (OFE) 铜连接器的电子束 (EB) 焊接。随后，对标本进行 X 射线计算机断层扫描 (CT) 和金相检查以表征关节。发现基材的残余氧含量是孔隙形成的原因。铜中只有极低的氧含量，使用强大的 EB 焊接技术，特别是对于铜材料，可以重复地实现无孔隙和无飞溅的焊接。通过相应地优化参数，即使在合金含有大量残余氧的情况下，接头也能实现低孔隙率。除此之外，还对孔隙分布进行了详细分析，并确定了工艺参数与焊接结果之间的良好相关性。