Influence of micro-structural parameters on fatigue life of discontinuous reinforced metal matrix composites

Abstract

The micro-structural parameters such as reinforcement shape, size, distribution, volume fraction, property mismatch, aging condition, bonding strength, and whisker orientation can influence the fatigue life of discontinuous reinforced metal matrix composites (DRMMCs). The strengthening effect plays a vital role in predicting the fatigue behaviour of DRMMCs. The modified shear lag (MSL) and enhance dislocation density (EDD) are two main factors that describes the strength of DRMMCs. In the present work, fatigue crack growth life model based MSL and EDD strengthening mechanism has been developed by integrating fatigue damage deformation at the crack-tip under the total strain-controlled conditions. The closed form expression predicts the dependency of particle size, reinforcement volume fraction and reinforcement constraint of the matrix on the fatigue crack growth life. The model fitting with experimental data affirms the appropriateness of proposed fatigue crack growth life prediction model for DRMMCs.