DEFORMATION BEHAVIOUR OF Al-5% Si ALLOY AT HIGH TEMPERATURES AND DIFFERENT STRAIN RATES.

The constitutive behavior of Al-5% Si alloy has been studied in the temperature range 500-800 K and strain rate range 0. 02-200 s** minus **1 for obtaining flow stress data and evaluating the mechanism of hot deformation. For this purpose, hot compression tests have been conducted on cylindrical specimens. From transient measurements of force, ram travel and temperature changes during deformation, the flow stress, true strain and rate have been calculated. The kinetics of deformation are described. At high temperatures and strain rates, deformation takes place by cross-slip of screw dislocations.