Grain Refinement Through Design Modification of ECAP Dies

Abstract

The need for super-plasticity and high strength leads to the development of Severe Plastic Deformation (SPD) techniques. The strength of the material is directly dependent upon the grain size of the material. During the simulation of ECAP process, the initial die designed with sharp corner angle reveals metal flash. Metal flash may fail the tip of the billet. To avoid and control the metal flash, the intersecting channels are redesigned with radius of 3mm and reveals smooth flow. ECAP die 900 and 1200 for square billets are made in H11 Steel channels, that are cut into 58×9.2×8.2mm for 900 machined in EDM process, similarly 1200 die with 52×9.2×8.2mm are made, including the Punch are made in same material of 155×9.2×8.2mm, respectively. Aluminum Automobile scrap were selected and melted in the open-hearth furnace, made round rods and square billets as per the die dimensions. Molybdenum di-sulphate, is used as a lubricant. Tensile Test was carried out for the Annelid specimen. Brinell hardness was checked and SEM test was carried out, for finding out the reason for the failure.