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利用两套模具控制变形,通过反复镦挤变形实现大塑性变形,成功制备了纳米晶纯铜材料。研究了镦挤变形过程的组织变化规律,以及镦挤次数、变形量与纳米纯铜显微硬度、晶粒尺寸之间的关系。结果表明,纯铜经过110次的反复的镦挤变形后,获得了均匀、细小的等轴晶,平均晶粒尺寸为77.1nm左右,显微硬度达到1610MPa(HV)。多方向的镦挤变形对细化晶粒过程有显著影响。多方向的镦挤变形,使平行滑移带形成网状结构,有效地使块体材料晶粒细化,随着变形程度的增加,晶粒逐步细化。
The use of two sets of mold control deformation, through repeated upsetting deformation plastic deformation, nanocrystalline pure copper material successfully prepared. The change rule of the structure during the process of upsetting and squeezing deformation was studied, and the relationship between the number of upsetting and extrusion, the microhardness of nano-pure copper and the grain size was studied. The results show that after repeated 110 times of upsetting deformation, the pure copper has uniform and fine equiaxed grains with an average grain size of about 77.1nm and a microhardness of 1610MPa (HV). Multi-directional upsetting deformation has a significant impact on the grain refinement process. Multi-directional upsetting deformation, the parallel slip band to form a mesh structure, effectively make the bulk material grain refinement, with the degree of deformation increases, the grain gradually refined.