Coupled anisothermal chemomechanical degradation solutions in one dimension

Abstract

This paper focuses on thermal oxidation of Silicon Carbide (SiC) – a key process of degradation in aircraft turbine components. In this work, passive oxidation is considered, which produces amorphous silica that is accumulated on top of the SiC substrate. The mathematical problem is formulated within the context of mixture theory (Gardiner G (2017) Aeroengine composites, Part 1: the CMC invasion. Composites World 31 July 2015: n. pag. Web. 06 Mar; Jacobson, J Am Ceram Soc 76(1):3–28, 1993), which allows to model multi-constituent behavior – fluid and solid in this case – within the same continuum domain, while retaining interaction terms between constituents. Preliminary isothermal results have shown that the phenomena of interest are captured: expansion due to chemical reaction, change in solid density from unreacted to fully-oxidized material, interactive force among constituents, and stress variation across reaction zone. The method presented considers the anisothermal evolution of the problem.