AlphaSTAR Corporation, Irvine, California, USA, has received the Department of Defense (DoD) Phase II programme award by the Defense Logistics Agency (DLA) for the design of new alloys for Additive Manufacturing entitled ‘Grain Boundary Engineering for Additive Manufacturing’.
The project is in collaboration with GE Research, University of Southern California (USC) Viterbi Center for Advanced Manufacturing, University of Michigan (UoM) Aerospace Engineering and Quadrus Corporation. The award intends to continue Phase I efforts in the development of technologies that can predetermine the microstructure of AM metal parts with optimal grain boundaries, resulting in predictable mechanical properties, including mode of failure for enhanced AM fabrication.
Due to the variability in the mechanical properties of additively manufactured metal parts, understanding the microstructure development & evolution during the AM process of metallic alloys is an important precondition for the optimisation of parameters to achieve desired mechanical properties in AM builds.
Dr Rashid Miraj, Director of Technical Operations at AlphaSTAR, explained, “Metallic alloys consist of individual crystallites commonly referred to as grains. Individual grain connections (grain boundaries) are formed through recrystallisation during metal part fabrication and heat treatment. A grain boundary is the interface between two grains, or crystallites. Grain boundaries influence the mechanical properties of the metal; hence, certain grain boundaries are preferred over others.
“Grain boundary engineering (GBE) in Additive Manufacturing refers to methodologies and technologies associated with the build process or post-build heat treatments that drive and generate preferred microstructure outcomes associated with an AM fabricated part,” he continued. “At its simplest, AM GBE may be achieved through variation of the build process that address both heating and cooling and triggers nanoprecipitation and material transformation. This technology will result in significant advancements related to the design of new parts and the repair of old parts associated with DoD supply chain. GBE for AM has the potential to increase the flexibility, scalability, and capability of AM produced parts.”
The ultimate objective of this Phase II program is to establish material performance screening, selection and improvement of AM driven legacy parts. Furthermore, it will continue to improve the developed ICME software, GENOA 3DP, which reduces trial & error in the AM process, and accelerates the cycle time for part qualification and materials development. Continued development of this critical technology will apply to all DoD sectors looking to improve the quality and reliability of AM parts to assist our Warfighters.