Predicting Thermal Stress-Induced Cracking via First-Principles-Derived Properties and Synthetic Microstructures: Case Studies in Ni–Ti, Al–Cu, and Al–Ti Systems

Abstract Multiphase alloys often exhibit superior performance relative to single-phase alloys due to synergistic interactions among their constituent phases. However, property mismatch between these phases can generate significant thermal stress during melt-based processing and under thermal cycling in service. Such stress may induce microcracking, ultimately leading to reduced mechanical performance. Thermal stress prediction in melt-based alloy processing remains challenging due to the limited availability of phase property data and the complexity of microstructures. In this study, a computational workflow integrating thermodynamic simulations, density functional theory (DFT) simulations, and finite element analysis (FEA) was developed to predict thermal stresses that develop during melt-based fabrication for a given alloy composition. The framework was applied to the Ni–Ni25Ti, Al–Al25Ti, and Al–Al33Cu systems, with samples fabricated via arc melting to validate the proposed local maximum principal stress (LMPS) model.