搅拌摩擦焊焊缝横截面塑性材料迁移行为分析

在搅拌摩擦焊过程中,焊缝塑性材料的迁移是保证焊缝的冶金完整性的重要因素.本研究通过采用镶嵌标示材料的方法,焊后观察焊缝横截面上塑性材料的迁移行为.研究结果表明:在焊缝横截面上,探针附近的塑性材料沿带左旋螺纹的探针表面从焊缝上表面螺旋迁移至焊缝底部,从四周向焊缝表面迁移,在厚度方向上形成一个连续迁移的循环路径.塑性变形的区域关于焊缝中心不对称,塑性材料在焊缝中心形成类似于倾斜"花瓶"状的形貌.从焊缝表面至底面,塑性变形区宽度逐渐减小,前进边塑性材料向焊缝表面迁移的距离小于返回边,前进边塑性变形区小于返回边.

Investigation of the Cross Section Transfer of Plasticized Materials in Friction Stir Welding for Aluminum Alloy

The transfer of plasticized materials was an important factor for ensure the full metallurgy of weld in friction stir welding. The material transfer in the cross section was visualized by lamella structure plates made up with thin copper foils and aluminum plates. It is shown that, In the cross section of the weld , the materials adjacent the pin will move downwards along the surface of the pin and the materials a little far from the pin which have counter-clockwise screw thread features will move adversely. Which make materials do circulate movement in the thickness of the weld. It was not symmetry about weld centerline the area which the material had deformed. The plasticized materials looked like a slantwise vase in the center of the weld. The width of the plasticized region became narrow form the top of the weld to the bottom of the weld, the plasticized materials where at the advancing side upwards to the top of the weld was smaller than the retreating side, The width of the plasticized region where at the advancing side was smaller than retreating side.