DISPERSION OF ELASTIC MODULUS AND THE COEFFICIENT OF THERMAL EXPANSION OF 2.5D-C/SiC COMPOSITES

摘要

In this work, we investigate dispersion of the elastic moduli and the coefficient of thermal expansion (CTE) of 2.5 dimension-C/SiC ceramic matrix composites (2.5D C/SiC CMCs). A parameterized double-scale model for 2.5D-C/SiC CMCs, in which the elastic moduli and CTE predicted are found to be in good agreement with experimental results, was proposed. Then, by combining this model with a numerical simulation method, the relationship between the microparameters, elastic moduli, and the CTE could be carried out. Then, the influence of the microparameters on the elastic moduli and CTE was investigated. Finally, the dispersion of the the elastic moduli and CTE was studied by the Monte Carlo method. The analysis results show that the span of warp, the volume fraction of the fibers, and the ratio of microporosity have a significant influence on the strength properties of 2.5D-C/SiC CMCs. The elastic moduli and CTE of 2.5D-C/SiC CMCs change with a variety of microparameters. Meanwhile, a series of experiments have been performed to study the distribution of the elastic moduli and CTE of 2.5D-C/SiC CMCs. Both the experimental and theoretical distributions of the elastic moduli and CTE with a variety of microparameters fit well with the normal distribution.