摘要
铝合金和镁合金在多材料结构中的混合应用可有效实现轻量化效果,以搅拌摩擦焊为代表的新型固相焊接技术在铝/镁异种合金连接中的应用是焊接领域的研究热点。文中基于扭矩热源模型,利用Abaqus软件分析了搅拌头转速对6061铝合金/AZ31镁合金搅拌摩擦焊搭接接头热-力场的影响。结果表明:受搅拌头产热和热传导散热的共同作用,接头表面和横截面温度场分别呈椭圆状和碗状,焊缝前进侧温度高于后退侧。接头残余应力主要由纵向应力和横向应力构成,轴肩边缘同时受热应力和机械应力的作用而具有应力峰值。此外,接头峰值温度和残余应力值均随搅拌头转速的提高表现出不同程度的增大。相关研究结果可为铝/镁异种合金搅拌摩擦焊工艺参数的设计与优化提供理论指导。
The mixed application of Al alloy and Mg alloy in multi-material structures could effectively realize the lightweight effect.The application of the new solid-phase welding technology represented by friction stir welding(FSW)in joining Al and Mg alloy was the research hotspot in the field of welding.In this paper,the Abaqus software was employed to analyze the effects of tool rotation speeds on the thermal-force fields of 6061 Al/AZ31 Mg dissimilar FSW lap joints based on the torque heat source model.The results showed that the surficial and crosssectional thermal fields of the joints were elliptic and bowl shapes respectively,and the peak temperature on the advanced side was higher than that of the backward side,which was due to the opposite influence of heat generation by FSW tool and heat dissipation via thermal conduction.The residual stress of the joint was mainly composed of longitudinal stress and transverse stress.The shoulder edge was subjected to both thermal stress and mechanical stress and therefore obtained the stress peak.In addition,the peak temperature and residual stress of the joint increased with the increasing tool rotation speed.The results might provide theoretical guidance for the design and optimization of process parameters of Al/Mg FSW joint.
出处
《焊接技术》
2021年第3期6-10,I0007,共6页
Welding Technology
基金
天津市自然科学基金青年项目(19JCQNJC02800)。
