ANALYSIS OF COEXISTENCE OF TWO KINDS OF MACRO-DEFECTS IN CUP-CUP AXISYMMETRIC COMBINED EXTRUSION

In this paper, the relationships between the region of the two coexisting kinds of macro-defects and the reduction in area, as well as between the region and the relative residual thickness of the billet are studied for the cup-cup axisymmetric combined extrusion, on the basis of the analytical expression obtained by the upper-bound approach. The presented model and conclusions are confirmed by the experimental results in this paper.