The constitutive flow behavior of 6061Al-SiCp composites at elevated temperature.

Hot deformation tests were carried out on l6061-18vol.%SiCp composites and the flow stress curves were developed as a function of temp. and strain rate. The steady-state flow was the main feature of the true stress vs. true strain curves in all the cases. The apparent activation energy for hot deformation of MMC was three times as high as the activation energy for self-diffusion in aluminum. No evidence of strain hardening was observed at higher strains (0.05 to 0.5) unlike in the case of fiber reinforced MMCs. This is possibly due to the relatively faster diffusional relaxation in particle reinforced composites