轴肩结构对搅拌摩擦焊过程中材料流动的影响

摘要

Considering the practical geometry of rotational tool and the relation between the material properties and temperature, the effect of shoulder geometry on material plastic flow behavior in friction stir welding is sim- ulated by the ANSYS FLUENT software. In the simulation, the plane shoulder, the inner-concave-flute shoulder and the concentric-circles-flute shoulder are studied. The results show that the change of shoulder geometry nearly has no effect on the trend of material flow. For the material flow velocity, the value of the concentric,cir- cles-flute shoulder is the biggest, while that of the plane shoulder is the smallest. For avoiding root defect, the rotational tool with concentric-circles-flute shoulder is better than that with inner-concave-flute shoulder,which is verified by experiment.%考虑材料参数随温度的变化关系以及搅拌头的实际结构形式,利用ANSYS FLUENT软件对搅拌摩擦焊过程中材料的流动行为进行了数值分析,研究了轴肩结构分别为平面、内凹与同心圆时的材料流动规律.研究表明,当轴肩结构发生变化时,焊件表面及内部的材料流动趋势基本相同;靠近焊件表面的材料流动速度在轴肩结构为同心圆时最大,在轴肩结构为平面时最小.从避免搅拌摩擦焊根部缺陷的角度看,同心圆轴肩的搅拌头优于内凹轴肩,这一规律得到了试验证实.