Estimation of Steady State Creep Behavior of Al₂O₃/YAG Eutectic Composite by Image-Based Finite Element Analysis

Abstract

Al₂O₃/YAG eutectic composite has been developed for a structural material used in ultra high temperature environments more than 1500°C such as in a gas turbine. Creep behavior is one of the important material properties in ultra high temperature materials. In the present study, we propose image-based finite element analysis for estimating the steady state creep behavior of the Al₂O₃/YAG eutectic composite. In the image-based finite element analysis, micro-structure of the material taken by a SEM is modeled into a finite element mesh using a software for image processing. Then finite element creep analysis is carried out to obtain the steady state creep behavior of the Al₂O₃/YAG eutectic composite by using steady state creep constitutive equations for both Al₂O₃ single crystal and YAG single crystal. The results of steady state creep behavior obtained from the image-based finite element analysis are compared with the experimental results. It is found that the steady state creep behavior of the Al₂O₃/YAG eutectic composite is accurately estimated by the image-based finite element analysis. Furthermore, we examine the effect of volume fractions of the constituents on the steady state creep behavior of the Al₂O₃/YAG eutectic composite.