MIT Lincoln Laboratory,
Keywords: 3D printing, feedstock powder, metal matrix composite, powder bed fusion, powder processing
Summary:The thermomechanical properties of particle-reinforced metal matrix composites (MMCs) are attractive for high-performance defense and commercial applications, but fabrication of MMC components with conventional methods is difficult, costly, and typically limited to components with simple geometry. Additively manufacturing particulate MMCs with selective laser melting (SLM) would be an ideal method, but the laser consolidation of these materials has been largely unsuccessful in matching the properties of conventionally produced MMCs. The challenges include spreading the heterogeneous powder, distributing small ceramic particles, and forming a strong bond between the metal and the ceramic. Here, by mechanically alloying AlSi10Mg and ceramic microparticles, we manufacture highly-reinforced aluminum composite powders with morphology tuned for SLM process conditions. We show that these powders flow and pack similarly to gas atomized aluminum powder. Using SLM, we achieve dense consolidation of these powders and demonstrate the potential for MMC feedstock powders to be produced with scalable, cost-effective methods.