1.绪言铝合金在热挤压或在其后的热处理时,人们很早就知道在表面层容易出现粗大的再结晶,以前基本上都是以正向挤压来进行研究,在挤压筒内壁与死区界面上由于承受着大的剪切变形和变形热而引起温度上升,可以认为是再结晶形成的原因并起着决定性作用.虽然还没有防止铝合金表面粗大再结晶的一般方法,但是按合金的种类添加抑制再结晶的合金元素, 1. INTRODUCTION Aluminum alloys have been known for their early occurrence of coarse recrystallization on hot extrusion or subsequent heat treatment. Previously, they were basically studied by positive extrusion. In the extrusion cylinder The inner wall and dead zone interface due to the large shear deformation and deformation caused by heat caused by temperature rise can be considered the reason for recrystallization and play a decisive role.Although there is no general method to prevent coarse recrystallization aluminum alloy surface, However, according to the type of alloy added to suppress recrystallization of alloying elements,