Nanocomposite powder for powder-bed-based additive manufacturing obtained by dry particle coating

Several dry processing techniques are assessed to elaborate metallic nanocomposite powders dedicated to powder-bed-based (PBB) additive manufacturing as laser-powder bed fusion (L-PBF) and Binder Jetting (BJ). Electrostatic assembly of nanosized silicon carbide (35 nm) particles at the surface of gas atomized aluminium powders (15-53 μm) is performed using mixers covering a range of mixing energy from rotative drum mixer to high energy mixers such as high shear paddle and acoustic mixers. Analyses of particle size distribution (PSD) of powders mixtures show that only high-energy mixers bring to a monomodal PSD describing a complete electrostatic assembly of nanoparticles. Statistic image analysis confirms the absence of plastic deformation of aluminium particles during mixing. The coating leads to a drastic increase of starting host powder flowability and apparent density, while reducing the host powder optical reflectivity. Finally, a surface oxidation of SiC nanoparticles affects the coating efficiency. • Nanocomposite powder for powder bed based additive manufacturing are developed by dry coating. • Dry coating of silicon carbide on aluminium powder is assessed for different mixing energy. • Dry coating of nanoparticles significantly improves flow and packing of metallic additive manufacturing powders. • Dry coating performances are higher using high shear paddle and acoustic mixers. • SiC surface oxidation impact the coating efficiency.