Fig. 4 shows the forged aluminum plates having a thickness of 3 mm for a forging interval of 5 mm. The plates
in Fig. 4(a) and (b) were forged by the punches having a flat and a taper bottoms, respectively. Comparing between
these punches, the flat bottom punch produced plates with waving on the sides of the plate and depression on the
surface of the plate. The taper bottom punch instead, reduces waving and depression. A large curvature was
observed on the plate formed due to the different reduction in thickness. Therefore, an exit guide consists of a side
guide and an upper guide was introduced during the forging process to reduce the curvature of the plate having an
inclined cross-section. The forged aluminum plates having an inclined cross-section with the exit guide and a taper
bottom punch are shown in Fig. 5. The curvature of the plate was reduced with the side guide.