Predicting Porosity in Freeze Casting with Explainable Machine Learning

Freeze casting is a versatile manufacturing process for producing porous materials with tailored microstructures and properties. However, due to the complexity and variability involved, predicting porosity based on process parameters remains a challenging task. Accurate prediction is crucial for designing materials as porosity significantly impacts their applications. This study applies machine learning techniques, including CatBoost, Random Forest, and XGBoost, to predict porosity using experimental data from 252 research papers covering ceramics, polymers, and composites. The CatBoost model demonstrated the best predictive performance with an <i>R</i> ² of 0.81 on the test set. Shapley Additive Explanations (SHAP) analysis revealed that solid loading had the most significant influence on predictions, with lower loading leading to increased porosity, as expected theoretically. The results highlight the potential of explainable machine learning to guide experimental design and optimize porosity in freeze casting materials.