SUPERPLASTIC DEFORMATION OF 15 VOL-PERCENT SICP LY12 ALUMINUM COMPOSITE UNDER AN ELECTRIC-FIELD/

In this paper, influence of an external electric field on mechanical p erformance of deformation, cavity formation, and fracture mechanisms h as been investigated during superplastic deformation of 15 vol% SiCp/L Y12 (LY12 matrix corresponds approximately to ASTM 2024) aluminum comp osite, The experimental results show that the appropriate electric fie ld makes the strain-rate sensitivity index increase and the superplast icity improve, The results obtained by scanning electron microscopy (S EM) show that the nucleation growth and linkage or coalescence of cavi ties is restrained by applying an external electric field; meanwhile, fracture transforms from intergranular tear to typical superplastic fa ilure, that is, fracture by formation and coalescence of cavities at p articles and boundaries.