Fracture toughness in metal matrix composites

Abstract

Evaluations of the fracture toughness in metal matrix composites (Duralcan reinforced with 15% of Al203 and SiC) are presented in this work. The application of Elastic Plastic Fracture Mechanics is discussed and the obtained values are compared with the ones obtained by means of Linear Elastic Fracture Mechanics. Results show that JIC derived KJC values are higher than the corresponding values obtained by direct application of the linear elastic methodology. The effect of a heat treatment on the material fracture toughness was also evaluated in which the analyzed approaches showed, not only different toughness values, but also opposite tendencies. A second comparison of the JIC and KJC values obtained in this work with toughness values reported in the literature is presented and discussed.