Cluster characterisation in a metal matrix composite

Inhomogeneities in the reinforcement of particulate metal matrix composites (PMMC change their post elastic behaviour. Thus it is important to qualify and quantify particle clustering. Images of an Al-Si/SiC PMMC are analysed here in order to calculate interparticle distance, intercluster distance, and distance from isolated particles to clusters. This is done on six images at x 100 magnification, two images at x 200 magnification and one image at x 50 magnification. The analysis is done through increasing size dilatations. This is applied to the nine images but also to random images, allowing thus a comparison of the nine images and random ones. This gives four characteristic distances, and also the cluster size and the link between clustering and cracking. The particle and cluster alignment in the extrusion direction is also shown. (C) 2001 Elsevier Science Inc. All rights reserved.