Grain Boundary Engineering: AlphaSTAR and the DLA Make a Big Leap Forward Towards Commercialization – AMS Speaker Spotlight

The partnership between AlphaSTAR and the Defense Logistics Agency (DLA) to make advancements in the application of Grain Boundary Engineering (GBE) isn’t the first time the two parties have teamed up together. In fact, AlphaSTAR has collaborated numerous times with the Department of Defense and supporting agencies in mission-critical applications throughout its 30+ year history. However, their most recent work together involving GBE which culminated in the showcase of the production of combat weapons, Damascus steel knives to be specific, at the DMC Conference in Tampa last December, was a particularly significant breakthrough. What was demonstrated was the on-demand printing of custom knives while tailoring the microstructure of the stainless steel used to fabricate them in order to optimize the knives for different applications. This was an important milestone for not only the tactical readiness of our defense capabilities but is also a validated proofpoint for the broader Additive Manufacturing (AM) industry that GBE has arrived and its commercial opportunities are imminent.

Playing a central role in the DOD’s Supply Chain, the DLA’s strategic objective has always been to enable a flexible supply chain that can accelerate initial builds, repairs and replace parts to keep our military and defense agencies as well-equipped as possible. As such, leveraging and promoting new technology developments like Additive Manufacturing (AM) has always been critical to its central mission of “delivering readiness and lethality to the Warfighter mission.”  Now, with the inevitability of AM moving to mass production, new breakthroughs are paving the way for the DLA to harness more of the benefits of AM and create a path for these emerging technologies like GBE to reach commercial customers. That is precisely why the DLA is supporting the development of Grain Boundary Engineering, which fully unlocks the potential of AM materials, and is calling on the AM community to further these advancements. A coalition led by AlphaSTAR Technology Solutions (ATS) that includes General Electric Research Center (GERC), the University of Michigan and Quadrus Corporation, has taken on this challenge and achieved several impressive breakthroughs.

Understanding microstructure development and evolution during the AM process of metallic alloys is an important precondition for the optimization of the parameters to achieve AM-built parts with “tailored” grain boundaries that enable predictable mechanical properties including mode of failure.  Predetermining the microstructure of AM parts gives the US Armed Forces tactical advantages when designing & building reliable weaponry, vehicles, aircraft, and other combat tools used in mission-critical environments.

From an engineering standpoint, the team’s innovations included validated algorithms, modules and integrated computational tools for AM metal that can predict AM build outcomes in terms of alloy compositions, presence of precipitates, use of nano/micro material inclusions, and alteration of process parameters to exploit thermal cycling within the AM platform. These capabilities have resulted in improved material properties including increased resistance to stress, corrosion, and cracking, desired architectures in terms of grain size and boundary angle; and the capability to optimize and ultimately customize build outcomes. The team employed (1) ICME thermo-physics; (2) Process map; (3) Meltpool engineering; and (4) Grain Boundary Engineering.  This is novel because AlphaSTAR utilized its GENOA 3DP software environment to identify the ingredients (composition) needed to improve material properties and the recipe (improved build plan-transferable to G-code) to make sure it happened.  The simulation capability was validated by fabrication of knives that will eventually be subjected to service loads to assess strength and flexibility.  The printed knives incorporate the improved microstructure (GENOA 3DP: TMg + Grain Boundary Engineering) with improved performance (GENOA: Virtual as-built part performance to meet specification).

Figure 1. Analysis of Two Knives and Validation of New Alloy Composition

From a practical standpoint, the fabrication of Damascus steel knives using Grain Boundary Engineering by the AlphaSTAR-led team proved to the DLA that improved parts in terms of strength and flexibility can be made on demand at the point of need rather that a remote factory followed by a prolonged storage waiting for a need and justification. The knives themselves represent commercially available combat knives in form and function. Just as importantly, the opportunities to extend this science to improve the effectiveness and quality of products manufactured across other industries like automotive, aerospace, industrial, consumer products, electronics, and medical devices is now more in focus.

AlphaSTAR’s project with the DLA highlights how its comprehensive package of ICME tools for AM process simulation, build optimization, and part qualification incorporating Grain Boundary Engineering makes initial product development affordable and accessible.  It reduces risk and production cycles based on trial & error by conducting virtual investigations to expand knowledge and increase understanding of the physical phenomena.  In summary, it signals a new era of, and accelerated adoption of, additive manufacturing now more enabled by a deeper level of virtual examination and the savings of quicker time-to-market. All of this while providing immediate benefit to the DOD supply chain and helping make our military stronger.

AlphaSTAR is participating at Additive Manufacturing Strategies, taking place in New York City from February 7-9, 2023. Rashid Miraj, Director of Technical Operations at AlphaSTAR, will be taking part in Session 2, Panel 3: Automation, AM and the Factory of the Future on February 9. Register for your ticket to attend here.