This study by Tonyali, B et al. investigates the spatial customization of the coefficient of thermal expansion (CTE) in functionally graded materials (FGM) through composition and phase control. Specifically, the potential for reducing CTE by adding Ti-6Al-4V to Al 2219 aluminum alloy was evaluated.

Sample Preparation and Methods:

Samples were produced using the Directed Energy Deposition (DED) method.

Compositions were designed with 10% increments between 100 weight% Al 2219 and 70 weight% Al 2219 (balance Ti-6Al-4V).

Thermodynamic and Microstructure Analyses:

Thermodynamic simulations were used for phase predictions, while homogenization methods were used for CTE predictions.

Experimental analyses identified Al2Cu and fcc phases in all samples, and aluminides were found in samples containing Ti-6Al-4V.

Thermal Mechanical Properties:

The CTE values of the samples were measured through thermomechanical analysis, and these values were found to be consistent with the CTE predictions from homogenization methods.

This study demonstrates that material properties can be predicted and optimized using compositional modifications, thermodynamic calculations, and homogenization methods.

For a detailed review, you can access the related study here.