A Predictive Model for Thermo-Mechanical Degradation in Al/Al₂O₃ Composites: Influence of Porosity and Microcracks

Abstract The present research investigates the thermo-mechanical degradation of Al/Al₂O₃ composites, focusing on the combined effects of porosity and crack damage on Young’s and shear moduli. While existing models primarily consider porosity, this work integrates both porosity and microcrack evolution, providing a more comprehensive understanding of stiffness reduction under thermo-mechanical loading. A predictive model is developed to assess the impact of temperature, alumina volume fraction, and microstructural defects on modulus degradation. The results highlight the significant role of thermal expansion mismatch in inducing stress concentrations, leading to crack propagation and interface debonding, particularly at higher temperatures. Unlike previous models that consider only porosity effects, this study integrates both porosity and microcrack evolution. The model’s accuracy is validated against experimental data and finite element simulations, demonstrating superior predictive capability. These findings provide a robust framework for optimizing metal-ceramic composites in aerospace and high-temperature structural applications where mechanical integrity under thermal stress is critical.