Partition of Plastic Work into Heat and Stored Energy in Metals

-This study investigates heat generation in metals during plastic deformation. Experiments were designedto measure the partition of plastic work into heat and stored energy during dynamic deformations under adiabatic conditions. A servohydraulic load frame was used to measure mechanical properties at lower strain rates, 10 -3 s -1 to 1 s -1. A Kolsky pressure bar was used to determine mechanical properties at strain rates between 103 s -1 and 104 s -1. For dynamic loading, in situ temperature changes were measured using a high-speed HgCdTe photoconductive detector. An aluminum 2024-T3 alloy and c~-titanium were used to determine the dependence of the fraction of plastic work converted to heat on strain and strain rate. The flow stress and 13 for 2024-T3 aluminum alloy were found to be a function of strain but not strain rate, whereas they were found to be strongly dependent on strain rate for c~-titanium. KEY WORDS--plastic work, heat, infrared detectors, dynamic, stored energy, cold work, high strain rates, Kolsky bar/SHPB