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Functionally graded materials enable the spatial tailoring of properties through controlling compositions and phases that appear as a function of position within a component. The present study investigates the ability to reduce the coefficient of thermal expansion (CTE) of an aluminum alloy, Al 2219, through additions of Ti-6Al-4V. Thermodynamic simulations were used for phase predictions, and homogenization methods were used for CTE predictions of the bulk CTE of samples spanning compositions between 100 wt% Al 2219 and 70 wt% Al 2219 (balance Ti-6Al-4V) in 10 wt% increments. The samples were fabricated using directed energy deposition (DED) additive manufacturing (AM). Al2Cu and fcc phases were experimentally identified in all samples, and aluminides were shown to form in the samples containing Ti-6Al-4V. Thermomechanical analysis was used to measure the CTE of the samples, which agreed with the predicted CTE values from homogenization methods. The present study demonstrates the ability to tailor the CTEs of samples through compositional modification, thermodynamic calculations, and homogenization methods for property predictions.
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This content will become publicly available on April 20, 2027
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.
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- Award ID(s):
- 2050069
- PAR ID:
- 10680636
- Publisher / Repository:
- Springer
- Date Published:
- Journal Name:
- JOM
- ISSN:
- 1047-4838
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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