新能源扁线电机hairpin激光焊接头组织与性能分析  

Microstructure and properties analysis of hairpin laser welded joints for new energy vehicles flat wire motors

作　　者：李远远 唐峰 柯凯[1] Li Yuanyuan;Tang Feng;Ke Kai(Huayu Automotive Electric Drive System Co.,Ltd.,Shanghai 201323,China)

机构地区：[1]华域汽车电动系统有限公司,上海201323

出　　处：《焊接》2024年第4期74-80,共7页Welding & Joining

摘　　要：以新能源汽车扁线驱动电机为主体,探究了扁线电机制造过程中hairpin连接线的激光焊接工艺。通过焊点金相、高速摄像、拉力测试、硬度测试、扫描电镜等测试手段,验证了扁线电机连接线激光焊的制造工艺可行性和焊接质量可靠性。结果表明:最佳焊接工艺参数为:激光功率3000 W、焊接速度200 mm/s、离焦量0 mm,焊接轨迹为ϕ2.5 mm的圆形、轨迹重复次数为5。无保护气体条件下激光焊接hairpin,焊点内部会出现气孔。能谱测试表明,气孔主要由氧元素引起。金相结果显示,焊点内部气孔率为0.5%,最大气孔直径为0.1 mm。拉力测试表明,拉力可达1414 N,远超标准要求。显微硬度测试结果显示,不同焊接热输入下激光焊hairpin接头焊缝区域和热影响区域均有一定程度的软化现象,但对焊缝区域的软化影响更为明显。Taking the flat wire drive motor of new energy vehicles as the main body,the laser welding process of hairpin connecting wires in the manufacturing process of flat wire motors was studied.The manufacturing feasibility and welding quality reliability of laser welding for flat wire motor hairpins had been verified through testing methods of metallography,high-speed photography,tensile testing,hardness testing,and scanning electron microscopy.The results showed that the optimal welding process parameters were laser power of 3000 W,welding speed of 200 mm/s,defocus distance of 0 mm,and welding trajectoryϕ2.5 mm circle with 5 repetitions.Under unprotected gas conditions,laser welding of hairpins might result in porosity inside hairpin welding joints.EDS testing showed that pores were mainly caused by oxygen elements.The metallographic results showed that the internal porosity of the joint was 0.5%,and the maximum porosity diameter was 0.1 mm.The tensile test showed that the tensile force could reach 1414 N,far exceeding the standard requirements.The micro-hardness test results showed that under different welding heat inputs,both the weld area and heat affected area of hairpin joints softened to a certain extent,but the softening effect on the weld area was more significant.

关 键 词：扁线电机 HAIRPIN 激光焊 组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]