搅拌摩擦焊接过程中材料流动形式

采用完全热力耦合模型对搅拌摩擦焊接过程进行模拟,并详细分析了搅拌摩擦焊接过程中的材料流动形式.结果表明,模型可以成功预测搅拌摩擦焊接过程材料流动和温度分布情况.通过对搅拌头周围材料流动的研究,分析了搅拌摩擦焊接过程中飞边现象形成的主要原因.研究了搅拌摩擦焊接构件不同厚度上材料的三维流动形式,通过与二维情况的比较证实,二维情况下的材料流动数值模拟结果对应于搅拌摩擦焊接构件靠近下表面部分的材料流动情况.从等效塑性应变的分布也能证实搅拌头轴肩对靠近上表面的材料行为具有明显影响,而对下表面附近材料行为影响较弱,从而说明二维情况对应三维情况靠近下表面的部分.

Material flow patterns in friction stir welding

Friction stir welding process is simulated by using a fully coupled thermo-mechanical model.The material flow patterns in the friction stir welding process are analyzed.The comparison with experimental results can validate the current model and shows that the material flows and temperature distributions can be predicted precisely.From the research on material flows around the welding tool, the formation of weld fash in friction stir welding is explained.The 3D material flow patterns on different thicknesses are studied, which is compared with the 2D case to show that the material flows obtained in 2D numerical simulation correspond to the ones near the bottom surface obtained in 3D simulation.The equivalent plastic strain distribution also shows that the shoulder can affect the material behaviors near the top surface and the effect of the shoulder becomes weaker near the bottom surface, which demonstrates that the 2D case correspond to the part near the bottom surface in 3D case.