Continuum slip viscoplasticity with the Haasen constitutive model: Application to CdTe single crystal inelasticity

• Published in: International journal of plasticity Vol. 11; no. 7; pp. 799 - 826
• Main Author: Moosbrugger, J.C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1995; Elsevier Science
• Subjects: Calculations; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Dislocations (crystals); Equations of state of solids; Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; Plastic deformation; Semiconducting cadmium compounds; Semiconducting tellurium compounds; Single crystals; Viscoplasticity; Constitutive equation; Inorganic compounds; Transition element compounds; Slip; Dislocations; Continuum; Inelasticity; Monocrystals; Internal stress; Temperature effects; Cadmium tellurides; Viscoplasticity; Thermodynamic properties
• ISSN: 0749-6419; 1879-2154
• DOI: 10.1016/S0749-6419(99)80004-7

Small strain constitutive equations are developed for the thermomechanical behavior of semiconductor single crystals, including dislocation density as an evolving parameter. The model of Haasen, Alexander and coworkers is modified (extended) to include evolution of coefficients in the definition of internal stress. These account for an evolving dislocation substructure. The resulting model is applied in a continuum slip framework to allow multiple slip orientations. Slip system interaction rules are adapted to include slip system interaction for multiple slip conditions and to suppress secondary slip and dislocation density generation for single slip orientations. The approach is discussed relative to other models for viscoplasticity of single crystals and is examined in the context of thermodynamics with internal state variables. The framework is used to correlate experimental data from compression tests of single crystals of the compound semiconductor CdTe from room temperature to near the melting point. Sensitivity of the model to uncertainties such as initial dislocation density is explored.