Method for predicting mass change of ceramic-based composite material in stress oxidation environment

Abstract

The invention discloses a method for predicting the mass change of a ceramic matrix composite material in a stress oxidation environment. The method comprises the following steps of determining the change rule of the number of matrix cracks of the material under the action of stress and high temperature; determining the change rule of the matrix crack width of the material under the action of stress and high temperature; determining a diffusion coefficient of oxygen in a crack channel; respectively determining the oxidation rate of each component; determining the volume change of the SiC fiberbefore and after the matrix reaction; determining an oxidation dynamics model of the material in a stress and high-temperature oxidation environment; determining the oxidation dynamics models at a crack diffusion stage and an interface layer expansion stage, and determining an oxide layer change rule and an interface consumption rule; determining a mass change rule of the material in the stress and high-temperature environment. According to the method, the combined action of stress and high-temperature oxidation on the oxidation mechanism of the unidirectional SiC / SiC composite material is considered, and the related theoretical support is provided for the mechanical property analysis of the ceramic-based composite material in the stress oxidation environment.

Description

technical field [0001] The invention belongs to the technical field of material quality change prediction, and in particular relates to a method for predicting the quality change of a ceramic matrix composite material in a stress oxidation environment. Background technique [0002] Silicon carbide fiber toughened silicon carbide ceramic matrix composites (Continuous silicon carbide fiber reinforced silicon carbide composites, hereinafter referred to as SiC / SiC) have excellent properties such as high temperature resistance, low density, high specific strength, and high specific modulus, making it a One of the irreplaceable new high-temperature structural materials, it is widely used in aviation and aerospace engine hot-end parts, aerospace back-and-forth heat protection systems, high-speed brakes, gas turbine hot-end parts, high-temperature gas filtration and heat exchangers, etc. [0003] During the service process of SiC / SiC material, it is not only corroded by high tempera...

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Problems solved by technology

[0008] The present invention aims at the deficiencies of the above-mentioned prior art, and provides a method for predicting the quality change of ceramic matrix composite materials in a stress-oxidizing environment, so as to solve the problem that stress and high temperature are not considered in the analysis of the quality change of unidirectional SiC / SiC materials in the prior art (>900°C) Oxidation co-action problem

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