Synthesis, microstructure and properties characterization of disintegrated melt deposited Mg/SiC composites

In the present study, elemental and silicon carbide reinforced magnesium materials were synthesized using an innovative disintegrated melt deposition method followed by hot extrusion. Microstructural characterization studies revealed the presence of minimal porosity and completely recrystallized matrix in all the unreinforced and reinforced samples. In the case of reinforced magnesium samples, a fairly uniform distribution of SiC particulates and good SiC-Mg interfacial integrity was realized. The results of microhardness measurements revealed an increase in the brittleness of the SiC-Mg interfacial region with an increase in the amount of SiC particulates. Results of physical and mechanical properties characterization revealed that the increasing presence of SiC particulates led to an increase in hardness and elastic modulus, does not affect 0.2% yield strength and reduces the ultimate tensile strength, ductility, work for fracture and coefficient of thermal expansion. An attempt is made to correlate the results of physical and mechanical properties testing with that of the microstructural characterization. (C) 2000 Kluwer Academic Publishers.