Study on the Process of Pure Shearing and Fracture for AISI-1020 and AISI-1045 Blanking with Negative Clearance
This paper carried through fine-blanking with negative clearance processing experiment with the AISI-1020 and AISI-1045 and obtained the work piece of fine blanking with negative clearance. The fractography photographs in the different deform regions of rollover zone, shearing band, fracture zone and under sheared surface were scanned by scanning electron microscope (SEM-JSM-6360LV). The research result indicates that the plastic flow of fine-blanking with negative clearance has been carried out to punch downspin, then jib at the place of allowance value, so that the length of work piece burnish band as much as possible to maximize and the length of the smooth shearing fracture could reach more than 90% thickness of the metallic sheet. Owing to the ejector negative direction blanking, the second burnish band could be formed in the process of ejecting and the work piece has no burr in the undermost sheared face. The place of fracture of fine-blanking with negative clearance has emerged into the middle of work piece, not into the sheared undermost. And the width of fracture band is very tiny, only 50-100 micron. The research result provides theoretic reference and the experimental data for the practice application. It has instructive significance and reference value to manufacturing application.
Qiusheng Yan, Jiabin Lu, Jun Wang and Hang Gao
W. F. Fan et al., "Study on the Process of Pure Shearing and Fracture for AISI-1020 and AISI-1045 Blanking with Negative Clearance", Advanced Materials Research, Vol. 135, pp. 215-219, 2010