Superplastic deformation of 15 vol% SiC_p/LY12 aluminum composite under an electric field

In this paper, influence of an external electric field on mechanical performance of deformation, cavity formation and fracture mechanisms has been investigated during superplastic deformation of 15 vol% SiC_p/LY12 (LY12 matrix corresponds approximately to ASTM 2024) aluminum composite. The experimental results show that the appropriate electric field makes the strain-rate sensitivity index increase and the superplasticity improve. The results obtained by scanning electron microscopy (SEM) show that the nucleation growth and linkage or coalescence of cavities is restrained by applying an external electric field; meanwhile, fracture transforms from intergranular tear to typical superplastic failure, that is, fracture by formation and coalescence of cavities at particles and boundaries.