Effect of Whisker Orientation on Monotonic and Fatigue Strength of Aluminium Cast Alloy Locally Reinforced by SiC Particles and Al2O3 Whiskers Under Monotonic and Cyclic load

Abstract

In this study, the effect of whisker orientation on monotonic and fatigue strength of aluminium cast alloy locally reinforced by SiC particles and Al2O3 whiskers are investigated. The material is monotonically and cyclically deformed to failure at room temperature. A significant effect of reinforcement orientation on the monotonic strength and fatigue strength are observed experimentally and numerically. With respect to the stress direction the whisker orientation gives significant difference in strength of this material. SEM analysis shows almost all whiskers are transversely debonded when whisker direction is perpendicular to the stress direction and almost all whiskers are broken when the whisker direction is parallel to the stress direction. A three-dimensional single whisker unit cell model of cylindrical shape whisker in the periodic boundary condition is conducted using finite element method (FEM) to describe the overall behavior of the composite. The prediction results based on FEM analysis is found to be in reasonable agreement with the experimental observations.