Synthesis and Characterization of Ultrasonically Atomized Al-Based Alloy Powders for Tunable Thermal Reactivity

Abstract

Reactive aluminum (Al) alloy powders are promising for advanced manufacturing, joining, and energetic applications, yet scalable routes that couple controlled reactivity with safe handling remain limited. While nanoscale Al powders ignite readily, their agglomeration, handling, and safety limit broad deployment. Here, we manufacture micron-sized Al-based powders produced by ultrasonic atomization (UA), targeting a balance of enhanced reactivity and process robustness. Binary systems (AlCu, AlSi, AlMg) and pure Al were synthesized, and their morphology, phases present, thermal stability, and oxidation behavior were characterized using XRD, SEM, and DTA/TGA in an Ar/O2 environment. We show that alloy selection and UA-controlled microstructure can modify the native Al2O3 passivation, alter oxidation pathways, and shift thermal onsets/exotherms. The results establish a manufacturing-forward framework for designing micron-sized powders with tunable ignition/oxidation behavior.