纯铜反复锻造工艺

Repetitive forging process for pure copper

采用DEFORM软件分析了纯铜反复锻造时的变形行为、速度场、载荷、等效应变以及工艺路线对等效应变的影响。结果表明:高宽比为1的试样,采用楔形凸模在第1次锻造的变形初期,试样存在转动现象,然后,试样左、右两侧沿纵向发生剪切,最后充满型腔;采用平端面凸模第1次反向锻造时,材料首先沿水平方向流动,然后,试样左、右两侧沿纵向发生剪切,最后充满型腔。上述变形过程会导致试样变形不均匀。按照A路线反复锻造后,试样上、下表面的等效应变较高,两侧较低;按照B路线锻造,可以在提高应变水平的同时提高变形均匀性。实验研究表明,经B路线4道次反复锻造后,试样获得了超细晶组织。

Deformation behavior,velocity field,load,effective strain and the effect of process route on effective strain during repetitive forging( RF) of pure copper were investigated by using DEFORM software. The results show that the rotation of sample whose ratio of height to width is one occurs at the initial stage during the first forging with inclined punch. Then the shear deformation along longitudinal direction is produced between the left and right sides of sample. Finally,the cavity is filled. While,the material initially flows along the horizontal direction during the first reverse forging with flat punch. Then the shear deformation along longitudinal direction is produced between the left and right sides of sample. Finally,the cavity is filled. The above deformation processes would lead to inhomogeneous deformation in the sample. The higher effective strain is located at the top and bottom surfaces of sample and the lower effective strain is at the both sides during RF with route A. The effective strain level and deformation homogeneity can be improved during RF with route B.The experimental studies show that ultra-fine grains can be obtained by four passes RF with route B.