Comportamento mecânico da liga Al 6351 submetida à extrusão angular em canais iguais e compressão multiaxial cíclica

Abstract

Equal Channel Angular Pressing (ECAP) is a severe plastic deformation process of metals that can supply samples with large dimensions at high production rates. Multi Axial Compression (MAC) is also a severe plastic deformation process where high strains can be reached by successive compressions. Cyclic and multi-axial deformation can lead to material softening in previously work hardened metals. It is thus expected that a material processed by ECAP followed by MAC would have outstanding mechanical properties. If Al and its alloys are subjected to such process it would be possible to obtain a material which with has low cost, low density, corrosion resistance, good thermal and electrical conductivity, good surface finish (intrinsic of Al and its alloys) in addition to the outstanding mechanical properties achieved by ECAP followed by MAC processing. The mechanical properties of an Al6531 aluminum alloy were analyzed under different conditions: annealed, after 1 and 4 passes of ECAP and after 1, 2, 3 and 4 cycles of MAC, utilizing special ECAP and MAC dies. The results show that processing by ECAP leads to an increase in material strength and that this is not dependent on the number of passes. MAC processing after ECAP led to some decrease in the strength of the material and to an appreciable increase in its work hardening capacity.