Effective Elastic Moduli and Characterization of a Particulate-Reinforced Metal Matrix Composite with Damaged Particles

A brief derivation of the expression is given for the effective bulk modulus of discontinuously reinforced metal matrix composites (DMMCs) with damaged particles (either complete voids as shattered particles or debonded particles). The analytical results are then compared with elastic moduli determined from nondestructive ultrasonic wave speed measurements of SiC particle-reinforced titanium matrix composites produced via shock wave consolidation. For the shock consolidated Ti-SiC metal matrix composites compacts, the overall particle damage mode is found to be similar to debonded particles and the effective volume fraction of damaged particles is determined to be 39% based on the data of both Young's and bulk moduli. Ultrasonic wave speed measurements combining with analytical and/or numerical results on overall elastic properties (Young's, bulk, and shear moduli, and Poisson's ratio) could be a useful tool in assessing the damage of particles in DMMCs.