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

¹ Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK
² Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China
³ School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
⁴ Departments of Aerospace & Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453, USA

^a Corresponding author: e-mail: y.huang@soton.ac.uk

Abstract

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.