It was pointed out that, in order to understand the role which was played by thermal stresses in the generation, multiplication and propagation of dislocations in CdTe single crystals which had been prepared by directional solidification, constitutive models were required which accurately reflected the elastic-viscoplastic behavior of CdTe over a wide range of temperatures. Here, relevant mechanical data on CdTe were reviewed. Constitutive equations which had been developed for the single-slip isothermal behavior of elemental semiconductor crystals, and which included the dislocation density as an important internal variable, were extended so as to include an additional dislocation arrangement internal variable as well as a high-temperature, time-dependent recovery behavior. The constitutive framework was incorporated into a continuum slip framework so as to include the possibility of multiple slip and to relate slip-system shear strain-rates to the macroscopic plastic strain rate. A comparison of the model was made with available experimental data for small strains over a wide temperature range. Slip-system interaction was also included. These constitutive equations could then be used in computational analyses of thermal stress generation, for comparison with crystals which had been grown under micro-gravity and normal-gravity conditions.

J.C.Moosbrugger, A.Levy: Metallurgical and Materials Transactions A, 1995, 26[10], 2687-97