Comparison of ceramic material effects on the flexural Weibull statistics and fracture of high volume fraction particle reinforced aluminum

The effects of the ceramic particle material on the flexural Weibull modulus, characteristic flexural strength, and damage parameters of particulate-reinforced metal-matrix composites were studied. Three high volume fill composites were fabricated using the pressure infusion casting technique: they were reinforced with SiC, B4C, and α-Al2O3 particles. Four-point bend testing determined the effects of particle material on flexural strength and elastic modulus. It was found the B4C and SiC composites had similar flexural Weibull modulus, low deflection, and similar damage parameters. The α-Al2O3 reinforced composite had the largest flexural Weibull modulus, highest deflection at failure, and largest damage parameter. Extensive microstructural and SEM fractographs were taken of the as-processes and fractured specimens. The mechanisms leading to the dominant failure modes are discussed.