Developing ultrafine-grained materials with high strength and good ductility for micro-forming applications

Materials with ultrafine grain sizes are attractive for use in micro-forming operations. High-pressure torsion (HPT) is an effective technique that allows disc materials subjected to torsional deformation to generate microstructures with significant grain refinement. Generally, ultrafine-grained materials exhibit high strength but their ductility is limited because they have both a low rate of strain hardening and a low strain rate sensitivity. A special processing route by utilizing HPT and short term annealing at different temperatures was developed to obtain balanced high strength and good ductility in an ultrafine-grained Al-1% Mg alloy which will increase the production rate and quality in micro-forming.