It is pointed out that the cross cracking, bending, distorting and twisting on the asymmetry extruded profile are caused by a vortex flow field in the deforming body of extrusion processes.

• 分析了型材挤压过程中各阶段的网格畸变情况,给出了挤压变形时的流速、应变和应力分布,揭示了造成异型型材挤压时出现扭拧、波浪和弯曲等缺陷的重要原因是变形体内存在一个涡流场。