摘要
对7075-T6铝合金和镀锌DP590钢板进行了搅拌摩擦搭接焊,并结合焊接过程中温度场、流场数值模拟结果,研究了金属间化合物(Intermetallic compound,IMC)厚度以及钩状结构对接头力学性能的影响规律。结果表明,IMC厚度较大时,IMC层在焊接残余应力作用下产生微裂纹,降低了接头冶金结合强度,当IMC厚度由0.8μm增大至4.3μm时,接头拉剪载荷降低17.8%。当钩状结构高度较大时,钩状结构上下两端宽度差较大,在拉剪载荷作用下钩状结构受力不均,薄弱部位易发生应力集中而断裂,降低了接头机械结合强度,接头性能随钩状结构高度的增大而下降。
7075-T6 aluminum alloy and galvanized DP590 steel are friction stir lap welded. Combining with the numerical simulation results of temperature field and material flow during welding, the effects of intermetallic compound(IMC) thickness and hook structure on the mechanical properties of the joint are studied. The results show that when the thickness of IMC is large, the microcracks are easy to initiate and expand at the IMC layer, which reduces the joint metallurgical bond strength. As the IMC thickness increasing from 0.8 μm to 4.3 μm, the joint strength decreases by 17.8%. The width difference between the upper and lower ends of the higher hook structure is larger. Under the tensile shear load, the hook structure is unevenly stressed. The weak part is prone to stress concentration and fracture, which reduces the mechanical bond strength of the joint. As the height of the hook structure increases, the strength of the joint gradually decreases.
作者
于海洋
胡志力
YU Haiyang;HU Zhili(Hubei Key Laboratory of Advanced Technology of Automobile Components,Wuhan University of Technology,Wuhan 430070;Hubei Collaborative Innovation Center for Automotive Components Technology,Wuhan University of Technology,Wuhan 430070)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2020年第6期65-72,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金(51775397)
中国汽车产业创新发展联合基金(U1564202)
湖北省技术创新专项重大项目(2019AAA007)资助项目。
关键词
搅拌摩擦焊
钩状结构
金属间化合物厚度
力学性能
friction stir welding
hook structure
intermetallic compound thickness
mechanical properties
