搅拌针形状影响搅拌摩擦焊过程金属塑性流动规律的数值模拟

考虑材料参数随温度的变化关系以及搅拌工具的实际结构,利用Fluent流体力学软件建立了搅拌摩擦焊的有限体积模型,对搅拌针的形状影响材料塑性流动行为的规律进行了研究.结果表明,材料的流动速度随着到焊件表面以及到搅拌针旋转轴的距离增加而减小；当减小搅拌针的锥角以及减小搅拌针的螺纹槽宽度时,焊件内部材料的流动速度得到提高.当搅拌工具在焊接过程中顺时针旋转时,对于左螺旋搅拌针,搅拌针附近的材料向下流动,而热力影响区材料的流动方向向上,此规律与右螺旋搅拌针时相反.

Numerical simulation of metal plastic flow in friction stir welding affected by pin shape

The finite volume model of friction stir welding was established on basis of the Fluent software,which considered the practical structure of rotational tool and the relation between the material parameters and temperature. The effect of pin structure on material plastic flow behavior was studied by numerical simulation. The results show that the flow velocity of material decreases with the increase of the distance away from the weldment surface and rotational axis of pin. The flow velocity of material inside weldment increased with decreasing of the cone angle of pine or decreasing of the width of screw pitch. As to the pin with left screw whose rotational direction is clockwise,the flow direction of material near pin is downward while the flow direction near the thermal-mechanical affected zone is upward,which is opposite to that of the pin with right screw.