Damage initiation in metal matrix composites

The process of damage by particle cracking has been followed in a composite of A356 Al containing 20% by volume SiC. The probability of particle cracking is influenced by both particle size and aspect ratio and the results indicate that the relative importance of these factors depends on the Weibull modulus of the SiC particles. A simple model is developed to describe the process of load transfer and crack initiation in the particles. This initial model does not take into account particle interactions and the role of clustering but does provide an initial fragment to describe the damage initiation process.