连续变断面挤压制品组织的变化规律

利用自行开发的连续变断面挤压新工艺设备,以工业纯铝为研究对象,进行了连续变断面挤压实验,研究了挤压制品的组织.结果表明:由于连续变断面挤压制品长度方向上各点的挤压比不同,各点的显微晶粒度也不同,晶粒随挤压比的增大而减小,在截面单一变化的试样中这种现象尤为明显;在同一截面上挤压制品的组织也不均匀,晶粒的尺寸由试样外层到中部逐渐变大,外层组织多为细小晶粒,中部组织多为粗大晶粒;由于热处理工艺的原因,部分组织还会发生二次再结晶,出现晶粒的异常长大现象.实验揭示了变断面挤压制品晶粒尺寸的变化规律.

Microstructural evolvement rule of extrusions in continuous variable cross-section extrusion

Fine aluminium was extruded by using self-developed continuous variable cross-section extruding equipment,and the microstructure of samples was studied.The results showed that the grain size is different in every section along the extruding direction owing to the different extrusion rate.The grain size is fined with increasing extrusion rate.The phenomenon is more obvious in a single cross-section extruded sample.The grains on the same section are not nonuniform.In the same section,the grain size is increased from outer part to center of the sample.The grains are mostly smaller in the outer part but bigger at the center.Some grains are very big,and the reason is that some grains recrystallize during heat treatment.The research gives the microstructural evolvement rule of extrusions in continuous variable cross-section extrusion.