A cyclic forward-backward extrusion process as a novel severe plastic deformation for production of ultrafine grains materials

摘要

A new severe plastic deformation (SPD) process based on a cyclic forward-backward extrusion (CFBE) is introduced for producing ultrafine grains in bulk alloys. CFBE was applied to AA1050 aluminum alloy and produced ultra-high plastic strains without any geometrical change. After only one cycle of CFBE, transmission electron microscopy (TEM) showed a significant grain refinement from 47 μm to about 1 urn. Also a substantial increase in the hardness, from 25 Hv to 47-52 Hv, was recorded by microhardness tests after one cycle of CFBE.