Producing hybrid metal composites by combining additive manufacturing and casting

The ORNL/Rice team proof of concept work has demonstrated how AMIPCs can enable new opportunities in the world of industrial design and materials selection by combining AM with casting technology. In particular, this processing strategy can be used to pattern the components at the sub-millimeter scale, providing exceptional control over microstructure and significant advantages over conventional processing technologies for manufacturing high-performance materials systems. By tuning the local geometry of a part, rather than the chemical composition of each layer, it is possible to reduce the formation of intermetallic phases that are often present in functionally graded materials produced using only fusion-based AM processes, avoiding a major challenge in the creation of functionally graded parts and increasing the potential number of applications of multi-material solutions. Further, while steel and aluminum were chosen for the initial work in AMIPCs, this processing strategy can be extended to many other materials combinations where the components possess dissimilar melting temperatures. In this proof of concept work, the lattice configuration used by the ORNL/Rice team was selected for its simplicity and ease of infiltration. Another opportunity for improving the performance of AMIPCs is shown through recent work in mechanical metamaterials^[17], which suggests that the lattice configuration can strongly influence the observed tradeoffs in material properties. Such approaches could be incorporated into the AMIPC manufacturing process, further expanding the range of potential material properties. The authors anticipate several developments in the field of additive manufacturing as AM processes continue to mature. Improved surface finishes realized by using powders with finer sizes will enable finer details in 3D-printed parts as well as in AMIPCs. Further advances in AM will reduce cost and increase throughput and these benefits will extend to AMIPCs as well. AMIPCs have the unique ability to tailor properties of interest in specific locations where required, greatly expanding the variety of parts that may be produced through hybrid materials and manufacturing approaches, integrating additive manufacturing into conventional industries and manufacturing processes.