COMPOSITIONAL AND MICROSTRUCTURAL DESIGN FOR ADDITIVE MANUFACTURING Phase-Based Properties of Al-Fe-Ni Samples: Characterization and Computational Framework Toward Compositionally Tailored Properties

This study presents a framework for mapping the effects of composition and phase fractions on the coefficient of thermal expansion (CTE) and elastic properties in the Al-Fe-Ni ternary, using thermodynamic phase calculations, first-principles property calculations, and experimental validation. The calculation of phase diagrams (CALPHAD) method was used to predict phases within the Al-Fe-Ni ternary, and the CTE and elastic constants of the phases were computed using DFT-based calculations, which were used to determine P-wave modulus and wave speed values. For multi-phase compositions, anticipated bulk CTE and P-wave modulus values were calculated using homogenization equations and individual phase properties. Arc-melted samples of compositions within the ternary were fabricated, and their phases, CTE, and wave speeds were measured, showing agreement with predicted phases and property trends. The approach presented in this work can be used towards property-informed design of alloys, joints, and functionally graded materials.