The dynamic properties of SiCp/Al composites fabricated by spark plasma sintering with powders prepared by mechanical alloying process

The dynamic compressive properties of SiC particle reinforced pure AI matrix composites, fabricated by spark plasma sintering technique with mixture powders prepared by mechanical alloying process, were tested in this paper. Two different average SiC particle sizes of 12 mu m and 45 mu m were adopted, and the compressive tests of these composites at strain rates ranging from 800/s to 5200/s were conducted by split Hopkinson pressure bar. The damage mechanism of the SiCp/Al composites was analyzed through the microstructural observations and high-precision density measurements. Results show that the dynamic properties and damage accumulation of these composites are significantly affected by the particle distribution, size, particle cracking, particle/matrix interface debonding and adiabatic heat softening. The composites containing smaller SiC particles exhibit higher flow stress, lower strain rate sensitivity, and less damage at high strain rate deformation. (C) 2009 Elsevier B.V. All rights reserved.