HIGH TEMPERATURE DEFORMATION BEHAVIOR OF CdTe. T. E. Stevens, J. C. Moosbrugger, F. M. Carlson, Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY 13699

The goal of this work is to investigate the role of inelasticity in the generation, multiplication and propagation of dislocations in directionally solidified CdTe.

High temperature deformation of CdTe is simulated using the MARC finite element code. A continuum slip viscoplastic model is incorporated, which allows prediction of three dimensional states of stress. Slip system interaction, dislocation arrangement variables and time-dependent recovery are extensions of the model proposed by Haasen and coworkers.

Creep experiments are modelled at high homologous temperatures, using 'dog-bone' shaped tensile specimens. Material response to various loading conditions, over time, is examined. Macroscopic plastic strain rate and dislocation density are calculated from values computed on the individual slip systems.

Experimentally, zinc-doped CdTe single crystals are subjected to creep loading. These small strain tests are conducted to characterize the mechanical behavior at elevated temperatures. A laser interferometric system was constructed to measure the small specimen displacements. Pre- and post-deformation dislocation densities are compared. Transmission Electron Microscopy is used to discern microstructural dislocation dynamics.