Experimental Evaluation and Phase-Field Model of Fracture Behavior of Alumina-Aluminium Graded Composite

Multilayered metal-ceramic composites belong to the class of functionally graded materials with a step-wise gradient in material composition. These advanced structural materials can be tailored to meet design requirements. Aluminum-matrix composites are one of the most attractive metal-ceramic composites due to low specific weight, good thermal conductivity, enhanced specific strength, and low cost of the constituent materials. A comprehensive investigation of the fracture properties and mechanisms of layered aluminum-matrix composites is required to enhance their utilization in practical applications. This chapter is focused on experiments and modeling of fracture in functionally graded AlSi12-Al2O3 composites. Three-layer bulk disks with 10, 20, and 30% volume fractions of Al2O3 are manufactured through powder metallurgy. Singleedge notched samples (SEVNB) are prepared from the bulk material and tested under four-point bending. The fracture tests are simulated using the phase-field modeling of brittle fracture. In the phase-field models, individual layers are considered homogeneous linear elastic isotropic materials with effective properties estimated by the rule of mixture. The length scale parameter is calibrated by fitting the numerically determined fracture loads to the experimental data. The phase-field model is then used to investigate the impact of the stacking sequence on the load-displacement curves of the fracture specimens. It is revealed that the stacking sequence may significantly affect the load-displacement curves, including changes to the maximum load and post-peak response. The ability of the phase-field model to capture the crack arrestment, branching, and deflection in functionally graded layered materials is shown.