新能源汽车驱动电机定子用扁铜线焊接工艺探究及接头性能分析

Investigation on Welding Process and Mechanical Properties of Flat Copper Wire for New Energy Vehicle Drive Motor Stator

使用环形光斑激光焊及钨极氩弧(TIG)焊对新能源汽车驱动电机定子用扁铜线进行焊接试验,并对焊接工艺及接头的性能进行探究与分析。研究发现,扁铜线环形光斑激光焊接的最佳工艺为中芯功率2500 W、环芯功率1500 W、焊接速度290 mm/s、离焦量+5 mm,所得到的接头成型良好,无气孔等焊接缺陷;TIG焊的最优工艺参数为焊接电流140 A,焊接速度150 mm/s,所得到的接头存在少量缩孔。环形光斑激光焊工艺得到的接头最大抗剪强度为132 MPa,其接头硬度最大值出现在焊缝中心,约为140 HV0.2;TIG焊得到的最大抗剪强度为110 MPa,其接头硬度最大值出现在焊缝中心,约为128 HV0.2。环形光斑激光焊获得的焊接接头在组织形貌及力学性能上均优于TIG焊,是更适用于扁铜线焊接的工艺。

Welding tests are carried out on flat copper wires for stator of new energy vehicles’drive motors by using two processes,ring spot laser welding and TIG welding.Moreover,the welding process and the performance of the joints are investigated and analyzed.The results show that the optimal process of flat copper wire laser welding is 2500 W for the center core power,1500 W for the ring core power,290 mm/s for the welding speed,and+5 mm for the defocusing amount,and the obtained joints are well formed without weld defects such as pores,etc.;the optimal process parameters of TIG welding are 140 A for the welding current,150 mm/s for the welding speed,and a small amount of shrinkage holes exists in the obtained joints.The maximum shear strength of the joint obtained by the ring spot laser welding process is 132 MPa,and the maximum hardness of the joint appears in the center of the weld,which is about 140 HV0.2;while the maximum shear strength obtained by TIG welding is 110 MPa,and the maximum hardness of the joint appears in the center of the weld,which is about 128 HV0.2.The welded joints obtained by ring spot laser welding are better than the TIG welded joints in the organization,morphology,and mechanical properties,and they are more suitable for the welding of flat copper wire.