Quantification of microdamage phenomena during tensile straining of high volume fraction particle reinforced aluminium

Particle reinforced composites are produced by infiltrating ceramic particl e beds with 99.99% Al. Resulting materials feature a relatively high volume fraction (40-55 vol. pet) of homogeneously distributed reinforcement. The evolution of damage during tensile straining of these composites is monitor ed using two indirect methods; namely by tracking changes in density and in Young's modulus. Identification and quantification of the active damage me chanisms is conducted on polished sections of failed tensile specimens: par ticle fracture and void formation in the matrix are the predominant damage micromechanisms in these materials. The damage parameter derived from the c hange in density at a given strain is found to be one to two orders of magn itude smaller than the parameter based on changes in Young's modulus. A sim ple micromechanical analysis inspired by the observed damage micromechanism s is used to correlate the two indirect measurements of damage. The predict ions of this analysis are in good agreement with experiment. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. AII rights reserved.