Computer-Aided Evaluation of Particle Distribution in Metallic Matrix Composites

摘要

Fabrication of aluminum matrix composites reinforced with ceramic particles via powder metallurgy techniques present considerable advantages, especially large flexibility of reinforcement volume content. However since metal particles are considerably larger than ceramic reinforcement, ceramic clustering become more and more frequent as the reinforcement proportion increases, and high ratio plastic deformations are mandatory. An experimental program has been developed to determine particle redistribution of ceramic reinforcement by mean of large-ratio extrusion of aluminum composites, containing between 0 and 20% vol. of reinforcement. The composites have been fabricated via a classic blending-pressing-sintering technique, based on powder mix of aluminum alloy and SiC, which resulted in significant occurrence of ceramic clusters. Composite samples have been hot extruded at different deformation ratios, and metallographicaly analyzed. Evaluation of particle redistribution by extrusion has been determined using a computer-based technique of image analysis for resulting optical micrographies.