Additive manufacturing is revolutionizing manufacturing by enabling layer-by-layer production of components from computer models. Metal additive manufacturing has been adopted by industry at a slower pace compared to 3D printing of plastics, polymers, and hydrogels. This Grant Opportunities for Academic Liaison with Industry (GOALI) project involves fundamental research to enable expansion of additive manufacturing of metals. The process enabled by this research will be focused on a specialized type of metals, called `nano-twinned' metals, which exhibit simultaneous high strength, high ductility, and high electrical conductivity. These properties are enabled by their special microstructure, which is distinctly different than conventional metals. Specifically, in the atomic structure of these metals, parallel arrays of specialized boundaries (twin boundaries, TBs) form in which atoms have a mirror symmetry with respect to the boundary. These boundaries strengthen the metal. Also, electric current can readily flow through mirror atoms in the boundary, making these materials well-suited for electrical applications. This fundamental research will result in an additive manufacturing process that can be adopted in many industries such as for structural applications, interconnects in electronics, and sensors. This research may result in a viable commercial low-cost 3D printer for metals, which can be adopted by academic research labs, educational facilities, and small manufacturing enterprises (SMEs). The partnership with industry on this GOALI project will facilitate such transition.
In this project, fundamental research will be conducted on a new process for additive manufacturing of metals with controlled twin lamella thickness and twin density, and hence controlled mechanical and electrical properties. The process is based on a localized pulsed electrodeposition process. Nano-twinned metals are ultrafine-grained or fine-grained metals that contain a high density of layered nanoscale regions. These regions are divided by coherent twin boundaries. Nano-twinned metals have an unprecedented combination of ultrahigh strength, high ductility, and high electrical conductivity. This type of metal in bulk form can be synthesized via various approaches including electrodeposition, recrystallization, phase transformation, and sputter deposition, and plastic deformation processing. However, there is no current process for additive manufacturing of nano-twinned metals. This project will develop a theoretical understanding of additive manufacturing of nano-twinned metals by localized pulsed electrodeposition (L-PED) using combined multi-physics simulation and multi-scale experiments. In addition, nano-twinned metals will be manufactured by 3D L-PED and the process-structure-property relationship of the printed metals will be investigated.
