dieThe surface of sheared edges for slight
clearance punching of JSC980Y with a (a) fixed die and n=3 and (b) moving die and n=10 for v=3 mm/s are shown
in Fig. 2. For slight clearance punching with a fixed die, as the punch and die are eccentric, the clearance is nonuniformly
distributed between the punch and die. The burnished surface is large between มุม =0 and 180° whereas
the fracture surface is large between มุม=180 and 0°. The condition of the surface of the sheared edge is remained for
n=2 and 3. In slight clearance punching of JSC980Y with a moving die, the fracture surface is large between
มุม=180 and 0° for n=1 as the punch and die are initially eccentric. However, for n=4 and above, the moving die was
shifted by the contact between the punch and sheet, and therefore almost all burnished surfaces were obtained in
the hoop direction.
Fig. 2.