Characterization of Nanocomposites Synthesized by Al-Si Casting Alloys Reinforced with Silicon Carvide

Abstract

This paper is aimed at studying the microstructure and mechanical properties of nano composites, processed via stir casting. The composites are based on the A356 aluminum alloy, reinforced with nano-SiC particles. The density measurements showed that the samples contained little porosity, and the amount of porosity in the composites increased with increasing volume fraction. The microstructures of composites were examined using optical microscopy (OM) and transmission electron microscopy (TEM). Microscopic observations of the microstructures revealed that the dispersion of the particles was uniform. The tensile strength (yield strength and ultimate tensile strength) and the Young's modulus improve with the addition of nano particles although some reduction in ductility is observed. The highest yield strength and UTS was obtained by 3.5 vol. % of SiC nano-particles. A relatively ductile fracture in tensile fractured samples was observed by fractography examination.