Superplasticity in magnesium-based composite
(School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 150001, China)
Harbin Institute of Technology, Harbin 150001, China)
Abstract: Superplasticity in a SiCw/ZK60 composite was studied. The samples were tested at temperatures ranging from 573K to 723K and at the initial strain rates ranging from 8.3×10-4s-1 to 8.3×10-2s-1. A maximum elongation of 200% was obtained at 613K and 1.67×10-2s-1 with a m-value of 0.35. The activation energy (98kJ/mol) approximates that for grain boundary diffusion (92kJ/mol) in magnesium. A strong 〈111〉 fibre texture was developed in SiC whiskers during superplastic deformation.
Key words: SiC whiskers; magnesium matrix composite; superplasticity; activation energy; texture