Rubber pad - constrained groove pressing (RP-CGP) and its application to grain refinement of aluminum sheets

A new severe plastic deformation process called rubber pad constrained groove pressing (RP-CGP) have been developed for producing ultrafine-grained metallic materials. In this process, repetitive shear deformation conditions is imposed on the sheet material by utilizing asymmetrically grooved die and a polyurethane rubber pad instead of the rigid punch, as in the CGP, through alternate pressing. In this study, commercial pure aluminum sheet was subjected to repetitive pressing using RP-CGP. The effects of the groove angle were investigated. Changes in mechanical properties measured by tensile and hardness tests were related to microstructure development. It is shown that a die design with a larger groove angle can result better grain refinement and improve properties.

Keywords:

Severe plastic deformation , Constrained groove pressing , Ultrafine-grained material , Aluminum