The US Army is planning to expand the use of additively manufactured parts in its M998 High Mobility Multipurpose Wheeled Vehicles (HMMWV, or Humvee), reports Breaking Defense, having recently produced a replacement battery bracket using Fused Filament Fabrication (FFF) Additive Manufacturing technology.
Following Additive Manufacturing, the bracket underwent a post-annealing stage to strengthen the part. The development process used two approaches aiming at eliminating slump and creep during annealing in addition to preserving part geometry. The US Army Research Lab (ARL) tested the deployment of a high-temperature support shell and building the components out of a filament that includes both a low-temperature, annealable phase, and a higher-temperature phase to stabilise the part during annealing.
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The study, which began three years ago, aimed to design and produce components for the Humvee using three filament types and three different AM machines to make the comparative quarter-sections. Trials were then conducted in eight processing conditions with the AM parts. The evaluations indicated that annealing was an effective strategy to increase the mechanical robustness of AM parts. Additionally, shell annealing was found to be an effective approach.
As a result of these tests, the components will be installed on Humvees for field testing with the Maryland Army National Guard.
In addition to producing the AM battery bracket, the Army is now reportedly interested in exploring the use of AM for other components. “We are looking for more using cases. We are looking for manufacturing partners. Our plan is to expand consideration to other parts,” stated Eric Wetzel, team leader for the project at the US Army Research Lab, at the 15th Annual Ground Vehicle Systems Engineering & Technology Symposium, in Novi, Michigan.