Application of a model for the work hardening behavior to Mg/SiC composites synthesized using a fluxless casting process

An understanding of the work hardening behavior of particulate reinforced metal-matrix composites is crucial in optimizing the parameters for deformation processing of these materials. In the present study, elemental magnesium and magnesium-silicon carbide composites were synthesized using the methodology of fluxless casting followed by hot extrusion. The microstructures of the composites were characterized and the mechanical properties were determined. The results of ambient temperature tensile testing on the extruded Mg and Mg/SiC samples revealed that an increase in the weight percentage of SiC particulates in pure magnesium increases the elastic modulus, did not affect the 0.2% yield strength, and reduced the ultimate tensile strength and ductility. A modified continuum model was applied to relate the work hardening behavior of the composites to microstructural parameters and to predict the fracture strain of the composites. The model is shown to predict the fracture strain of the composites quite accurately for all the three weight fractions of reinforcements evaluated in this study. (C) 2002 Elsevier Science B.V. All rights reserved.