Effects of Random Particle Dispersion and Particle Volume Fraction on the Indentation Behavior of SiC Particle-Reinforced Metal-Matrix Composites

Abstract

The present composite structure models assume that reinforcement particles are located in a repeated arrayed order through metal matrix. This study investigates the effect of both random particle distribution and particle volume fraction on the indentation behavior of Al 1080/SiC particle reinforced metal—matrix composites under a spherical indenter. The ceramic particles were distributed randomly in a certain particle volume fraction through aluminum matrix in order to achieve a similar structure to a real particulate composite structure as possible. The particle volume fraction strongly affects permanent indentation surface profiles and indentation depths. The indentation profile becomes smoother, and the peak indentation depth increases as the particle volume fraction decreases. The random particle distribution has a small effect on the peak indentation depth but affects strongly the permanent indentation profiles as well as the residual stress and strain fields in the indentation region. A small increase appears in the local particle concentration in the indentation region and is affected considerably by the random particle distribution. The hardness tests as well as the scanning electron microscopy micrographs of the indentation regions of specimens with different particle volume fractions are in good agreement with theoretical analysis.