Deformation behaviors of high strain rate superplastic PM 17%SiCp/2024 Al (with SiCp size of 3.5 mum) composite rolling sheet after heat treated and cold-rolling were investigated in the temperature range of 753 K-853 K. A maximum tensile elongation of 259% is obtained at 813K and a strain rate of 10(-1) s(-1). The maximum value of strain rate sensitivity m is 0.25. The activation energy is 144 kJ/mol and 202 kJ/mol in the temperature range of 753-793 K and 813-853 K, resepectively, closed to that of lattice-diffusion in pure aluminum (142 kJ/mol). The deformation mechanism of composite is grain boundary sliding of matrix.
修改评论