A Comparative Study of Commercially Pure Aluminum Processed by ECAP Using Conventional and New Die

Abstract

Equal channel angular pressing (ECAP) is one of the techniques used in metal-forming processes but it runs into severe difficulties in die design. The role of friction in the die is important in regard to increasing workpiece internal stress while simultaneously reducing material strain hardening. Owing to internal stress, the workpiece fails in successive passes. This article throws light on the workability of commercially pure aluminum processed by ECAP using both conventional and new dies. The experiment was carried out for both circular and square samples of the same cross-sectional area. The samples were extruded by up to three passes in routes A and C. The ultimate tensile strength was 20% higher than in the conventional die samples. The workability of the ECAP samples is discussed from the compression test. The experimentally validated results are discussed using the Cockcroft fracture criterion. The enhanced mechanical properties, with a slight reduction in workability of the second and third passes in both routes, are discussed for both conventional and new die samples. The compressive strength is higher than the tensile strength in both dies. The new ECAP die achieved better mechanical properties than the conventional die samples and supports the same workability.