Michael R. Sullivan, Graduate Student, University at Buffalo, The State University of New York
Three-dimensional (3D) printing is innovatively conducted by thixotropic metal-based paste deposition. Upon solidification, the paste becomes a metal-matrix composite that exhibits low thermal expansion (thereby enhancing the interlayer bonding), high creep resistance, high elastic modulus and high strength. The method is to provide a cost-effective high-throughput 3D metal printer that is amenable to the printing of large objects. Aluminum is an important metal for light-weight structures and structures that require high thermal conductivity. The low cost, high deposition rate, feasibility of printing aluminum and use of metal ingots as the feedstock are in contrast to current methods which mainly involve a laser/electron beam in conjunction with metal powder as the feedstock. Improving the metal ingot feedstock microstructure is also important in in order to produce better quality composites with improved ease of 3D printing. The use of metal powder makes aluminum printing difficult, due to the protective oxide on each aluminum particle, and degrades final composite quality. The printer design, feedstock design and printed material quality will be addressed for the case of aluminum composite printing.