Ultrafine pure aluminium through back pressure equal channel angular consolidation (BP-ECAC) of particles

Pure Al particles were synthesised into bulk materials using back pressure equal channel angular consolidation (BP-ECAC) and further deformed up to 4 passes of ECAP at 100 C with the application of 50 MPa in back pressure. Ingot metallurgy (IM) Al was processed under the same conditions to provide comparison. The microstructures were characterised using TEM for grain size and shape as well as misorientations. In general, the grains were finer and misorientations larger in the PM (powder metallurgy) materials than in the IM materials. The tensile strength of the PM materials was significantly higher than that of the IM materials. Different work hardening behaviours were observed between the materials after 1 pass and those after 4 passes.