A random microstructure-based model to study the effect of the shape of reinforcement particles on the damage of elastoplastic particulate metal matrix composites

摘要

The mechanical properties of materials are greatly affected by the occurrence of the first damage during the loading process. This study presents a comprehensive investigation of the effect of particulate shape and combination of two shapes or more, as a design parameter, on the damage mechanism of particulate-reinforced metal matrix composites (PRMMCs). In the context of a random microstructure-based finite element modelling, the proposed model accounts for all possible failure modes; plastic deformation and ductile cracking of the matrix, matrix-particle interface decohesion, and brittle fracture of the reinforcement particles. The matrix plastic deformation and cracking are, respectively, modeled via Johnson-Cook constitutive relation and Johnson-Cook ductile fracture model. The cohesive zone method is adopted to simulate the particle-matrix interfacial debonding. The particle fracture is simulated using an elastic-brittle cracking model, in which the damage evolution criterion depends on the crack opening energy. An extensive parametric study is carried out to explore the effect of different shapes of SiC particles; circular, hexagons, squares, triangles, and their combinations, on the damage mechanism and consequences of failure of A359/SiC particulate composites.