Novel severe plastic deformation technique—accumulated extrusion (AccumEx)

Abstract

Accumulated extrusion, a novel severe plastic deformation technique based on conventional extrusion process, is proposed and has been validated on commercial pure aluminium sheets. Four sheets were extruded together at 75% reduction, and this product was recut into four pieces and reextruded up to eight passes to a strain of 13.2. The tensile strength increased up to 200 MPa after six passes. The elongation to failure was 21% after one pass and 6% after six passes. Ultrafine grains with average grain size of 600 nm were observed after eight passes. The refinement process was monitored along all three directions. Texture evolution played an influential role on the misorientation profile and high angle grain boundary fraction.

Keywords:

• AccumEx
• Severe plastic deformation
• Ultrafine grains
• High angle grain boundaries