Optimization of Die Parameters in Annular Channel Angular Extrusion Based on Strain Distribution Uniformity

In this paper, a recently developed backward extrusion method enforcing severe plastic deformation is modified for processing cup-shaped part with homogeneity strain. Variation of channel angles (Φ) and corner angles (Ψ) have been employed to obtain a better strain distribution. The performance is analyzed using finite element modeling Deform 3D commercially available software. To verify the simulation results, the experiment was carried out for AZ80 magnesium alloy. The present work investigates effective strain distribution behavior, analyzed by several strain regions during the forming process. Furthermore, the influence of different channel and corner angles on the strain distribution uniformity of the wall in the formed part is especially evaluated. The best strain homogeneity is obtained with Φ=75° and Ψ=60°. Particularly worth mentioning is that the strain uniformity achieved by this novel method is better than that obtained in the conventional backward extrusion. While the smaller corner angle (Ψ) can develop gradient effective strain distribution, adversely affecting the strain homogeneity.