Thermal expansion behavior and analysis of Al/AlN interpenetrating phase composites with different preform porosity

In this work, the coefficient of thermal expansion (CTE) of Al/AlN interpenetrating phase composites (IPCs) has been measured based on the length change from room temperature (RT) to 200 °C. 3D representative volume elements (RVEs) are created to model the microstructures of Al/AlN IPCs and the finite element models generated from RVEs are used to study thermal expansion behavior. CTE was predicted utilizing the finite element method (FEM) and thermo-elastic models of Kerner, Turner and Schapery, after which the results were compared with the experimental values. According to experimental results, a notable reduction in the CTE of IPCs is observed as preform porosity decreases. This shows that an AlN preform can effectively enhance dimensional stability. A comparative analysis of extant literature indicates that IPCs may attain a lower CTE compared to particle-reinforced composites. Experimental data align closely with analytical models. The FE simulation results demonstrate better consistency with experimental data only under conditions of high preform porosity, since residual thermal stresses and plastic deformation were not considered.