Evaluation of a Laboratory-Scale Gas-Atomized AlSi10Mg Powder and a Commercial-Grade Counterpart for Laser Powder Bed Fusion Processing

Abstract

Laser powder bed fusion (LPBF) is an additive manufacturing technology that implies using metal powder as a raw material. The powders suitable for this kind of technology must respect some specific characteristics. Controlled gas atomization and post-processing operations can strongly affect the final properties of the powders, and, as a consequence, the characteristics of the bulk components. In fact, a complete characterization of the powders is mandatory to fully determine their properties. Beyond the most used tests, such as the volume particle size distribution (PSD) and flowability, the PSD number, the Hausner ratio and the oxidation level can give additional information otherwise not detectable. The present work concerns the complete characterization of two AlSi10Mg powders: a commercial-grade gas atomized powder and a laboratory-scale gas atomized counterpart. The laboratory-scale gas atomization allows to better manage the amount of the fine particles and the oxidation level. As a consequence, a higher particle packing can be reached with an increase in the final density and tensile strength of the LPBF bulk samples.

Design and Characterization of Innovative Gas-Atomized Al-Si-Cu-Mg Alloys for Additive Manufacturing

“…Powders with a composition AlSi10Mg + X Cu with copper contents of 0, 4, 8, and 20 wt% were produced using gas atomization. The process was carried out using a HER-MIGA 100/10 VI gas atomizer provided by Phoenix Scientific Industries (Phoenix Scientific Industries Ltd., Hailsham, East Sussex, UK), utilizing the experimental setup described in Marinucci et al [32]. Starting from the AlSi10Mg system and progressively adding pure copper element to obtain the desired compositions, the gas atomization process was carried out using an alumina crucible with a capacity of 10 kg of steel, or equivalent volumes, and the molten metal was forced to pass through a nozzle with a diameter of 2.5 mm.…”

Recycled Aluminium Feedstock in Metal Additive Manufacturing: A State of the Art Review

“…Although the particle size distribution is controllable by changing process parameters such as orifice diameter, not all particles fall into the size range suitable for AM (23-45 μm for LPBF) and (70-105 μm for DED). Marinucci et al [91] used a commercial gas atomiser to manufacture AlSi10Mg powder from melt, and after sieving to size range of 20-50 μm, obtained 30% powder fraction relative to original powder amount. With innovative nozzle design and process optimisation, the desired particle size fraction can be increased and rejected particles can be remelted [92].…”