Precipitation distribution in mechanically alloyed Al-Cu-Li powders processed via friction consolidation

Friction consolidation (FC) was deployed to illustrate the mechanical alloying effect of Al-Cu, Al-Li, and pure Cu powder through phase transformation behavior. A progressive material flow from the periphery to the center of the FC die was witnessed, along with expansion perpendicular to the direction of rotation, indicating various degrees of alloying. Two types of precipitate, δ′Al3Li and T1(Al2CuLi), were identified, exhibiting different distributions, attributed to variations in Cu content and thermo-mechanical processing. Mechanical tests showed slight anisotropic mechanical properties of the consolidated samples. By estimating the precipitate strengthening effect using physical models, the strengthening of δ′ was found to be more prominent than that of T1, which might be more prone to strain localization. Overall, the results demonstrate the feasibility of FC in processing Al-Cu-Li alloys and serve as basis for further improvements in the final product through the addition of minor alloying elements, demonstrating an energy-efficient manufacturing process for such alloys.