Deformation stability of Al 7075/20%SiCp (63µm) composites during hot compression

Stir cast Al 7075/20%SiCp composites were subjected to compression testing at strain rates and temperatures ranging from 0.001 to 1.0 s⁻¹ and from 300 to 500°C respectively. The associated microstructural transformations and instability phenomena were studied by observations of the optical electron microscope. The power dissipation efficiency and instability parameter were calculated by using the dynamic material model and plotted with the temperature and logarithm of strain rate to obtain processing maps for strains of 0.5. The domain of higher efficiencies corresponds to dynamic recrystallization during the hot deformation. Using the processing maps, the optimum processing parameters can be identified for effective hot deformation of Al 7075/20%SiCp composites.