Production Of High Silicon Aluminium Powders With Tailored CTE

In recent years, Laser Powder Bed Fusion (L-PBF) has emerged as a promising alternative manufacturing technique for hypereutectic Aluminum-Silicon alloys. Aluminium alloys containing high silicon are of special importance in terms of thermal management applications owing to their low density, high thermal conductivity and tailorable coefficient of thermal expansion (CTE). In this work, an alloy design, backed by thermodynamic simulation to determine the effect of silicon content on CTE, was carried out with the aim of reaching a CTE value compatible with that of the standard Ni plating. Following the results of simulation, hypereutectic aluminum-silicon powders were produced by gas atomizing. The powders were characterized in terms of microstructure and composition (by SEM and EDS), granulometry, rheology, and laser absorbance by UV-Vis-NIR.