Elastic constants of metal/ceramic composites with lamellar microstructures: Finite element modelling and ultrasonic experiments

摘要

The elastic properties of single domains of lamellar AlSil2/Al_2O_3 composites produced by metal infiltration of freeze cast preforms have been examined. The anisotropic elastic constants determined from ultrasonic phase spectroscopy (UPS) experiments have been compared to microstructure based FE-mod-els created with the program OOF2, micromechanical models (Mori-Tanaka and inverse Mori-Tanaka) and an analytical model for an ideal laminate. The influences of lamellae orientations and ceramic contents on the elastic constants have been investigated. Along the lamellae directions the microstructure based FE model and the inverse Mori-Tanaka model are in good agreement with experimental results. Perpendicular to the lamellae the experiment shows a stiffer than expected elastic behaviour.