摘要
提出了一种基于跑道线圈的板料磁脉冲焊接新方法。通过数值模拟、焊接实验以及测试分析,研究了放电电压、垫片间距以及飞板壁厚对板材焊接变形及温升的影响规律,阐明了焊接界面缺陷产生的原因,揭示了Al-Al接头的失效机制。结果表明:焊接碰撞速度随着放电电压及垫片间距的增加而增大,而随飞板壁厚的增加而减小;垫片间距的减小及飞板壁厚的增加会改善焊接碰撞角度;飞板厚向温度分布方式与电流流向有关,跑道线圈弯道段感应涡流的密度高于直道段;焊接接头界面中的微孔隙是由于局部金属“快熔快凝”导致的,而间隙熔融物是射流产生的高温“粒子团”卷入界面中凝固后形成的;Al-Al焊接试样在剪切强度达到24 MPa时发生剪切分离,这种失效方式由线形焊缝伴随微孔隙共同造成。
A new method for sheet metal magnetic pulse welding based on runway coil was proposed.Then,the influence laws of dis-charge voltage,gasket spacing and flyer sheet wall thickness on the welding deformation and temperature rise of sheet were studied through numerical simulation,welding experiments and test analysis.Furthermore,the causes of welding interface defects were clarified,and the failure mechanism of Al-Al joints was revealed.The results show that the welding collision speed increases with the increasing of discharge voltage and gasket spacing,but decreases with the increasing of flyer sheet wall thickness.The reduction of gasket spacing and the in-crease of flyer sheet wall thickness can improve the welding collision angle.The temperature distribution pattern of flyer sheet in the thick-ness direction is related to the current flow direction,and the density of induced eddy current in the curved section of runway coil is higher than that in the straight section.The micropores in the welded joint interface are caused by the"fast melting and fast solidification"of lo-cal metal,while the interstitial melt is formed by the high-temperature"particle clusters"generated by the jet flow and involved in the in-terface and solidified.The Al-Al welding sample undergoes the shear separation when the shear strength reaches 24 MPa,and this failure mode is caused by linear welds accompanied by micropores.
作者
唐天宇
黄亮
周巍
谢冰鑫
李中豪
时恬
孙怡然
Tang Tianyu;Huang Liang;Zhou Wei;Xie Bingxin;Li Zhonghao;Shi Tian;Sun Yiran(State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《锻压技术》
CAS
CSCD
北大核心
2024年第2期53-61,70,共10页
Forging & Stamping Technology
基金
国家自然科学基金面上项目(51975229)
湖北省重点研发计划项目(2020BAB139)
武汉市应用基础前沿项目(2020010601012178)。
关键词
磁脉冲焊接
跑道线圈
界面形貌
失效机制
铝合金
magnetic pulse welding
runway coil
interface topography
failure mechanism
aluminum alloy
