搅拌摩擦焊焊缝材料二维塑性流动研究

用紫铜作标示材料 ,进行了LF6铝合金的搅拌摩擦焊对接试验 ,焊后截取了焊缝的水平面试样 ,对标示材料在焊缝中的流动痕迹进行了分析。研究结果表明 ,搅拌摩擦焊过程中 ,焊缝材料流动与焊缝中心是不对称的 ,在前进边有材料往前流动也有材料向后流动 ;在返回边材料只是向后流动 ,且有部分材料进入前进边 ;为了分析试验观察到的沿焊缝水平面材料的流动形态 ,本文尝试建立了一个二维挤压模型 ,在该模型中认为在探针的周围有一个形状不变的热塑性区域 ,并用运动分解、合成的方法研究了探针周围热塑性材料的流动趋势 ,用该模型模拟了标示材料在焊接过程中的流动过程 ,模拟结果能解释试验所观察到的现象

The Studies of Material Two-Dimensional Plastic Flow in Friction Stir Welding

The sew horizontal material flow in friction-stir-butt-welded LF6 was investigated by using insert tracer material which was made of T1. The result indicated that the sew material flow was asymmetrical during friction stir welding. In advancing side, some material flowed forward and some flowed back. In retreating side, the material only flowed forward and some flowed into advancing side. To analyze the sew horizontal material flow pattern, a tentative two-dimension extrusion mode was presented based on the assumption that there was a thermal plastic zone closed to the pin and the shape of the zone was steady during welding. We studied the thermal plastic material flow around the pin using the theory of action separation and combination, and the result that the tracer material flow was simulated by the mode could explain what we investigaed in experiment.