Repair of 5th Generation Aircraft
The global scientific and engineering community is facing challenges in metal part production and repair due to logistical and economic factors. To address these issues, there is a growing demand for sustainable additive manufacturing (AM) solutions, specifically at the Point-of-Need (PON). Government agencies, particularly in the United States, are seeking ways to reduce strain on supply chains, natural resources, and active sustainment through AM adoption. AM offers resource management by producing less waste per component, economic design optimization for lightweight and efficient parts, and reduced chemical byproducts compared to traditional manufacturing methods.
A significant focus has been on recycling using AM, particularly with plastic materials. However, there is a strong interest in recycling harder materials like metals, ceramics, and composites for military vehicle applications. The Strategic Environmental Research and Development Program (SERDP) has been supporting research on Direct Additive Recycling (DAR), which uses waste materials, such as machine chips and damaged scrap, as feedstock for metal AM and repair. The process, known as Additive Friction Stir Deposition (AFSD), is a solid-state additive manufacturing technique that allows fabrication of components with similar properties to the feedstock material.
Recycling aluminum through AFSD has shown promising results, offering significant energy and greenhouse gas emission savings. AFSD breaks up inclusions in the material, leading to robust metallurgical bonds between layers and eliminating the need for extensive cleaning and sorting. Although AFSD has advantages over other AM methods, it has limitations, such as the need for finish machining and restricted build accuracy. Future research opportunities include developing continuous feeding, using round feedstock for hard materials, and exploring in-situ resource utilization for space exploration.
Overall, DAR with AFSD holds great potential for sustainable and efficient manufacturing, both on Earth and in outer space, by recycling and reusing materials at the PON, thus minimizing waste and environmental impact.
- AA7075 and the AFSD process
- Strength
- Ductility
- Low density
- High ballistic limit velocity
- Design flexibility
- As-built material integrity
Publications
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G. G. Stubblefield et al., “Ballistic Evaluation of Aluminum Alloy (AA) 7075 Plate Repaired by Additive Friction Stir Deposition Using AA7075 Feedstock,” J. dynamic behavior mater., vol. 9, no. 1, pp. 79–89, Mar. 2023, doi: 10.1007/s40870-022-00363-6.
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D. Z. Avery et al., “Evaluation of Microstructure and Mechanical Properties of Al-Zn-Mg-Cu Alloy Repaired via Additive Friction Stir Deposition,” Journal of Engineering Materials and Technology, vol. 144, no. 3, p. 031003, Jul. 2022, doi: 10.1115/1.4052816.
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C. J. T. Mason, D. Z. Avery, B. J. Phillips, J. B. Jordon, and P. G. Allison, “Strain Rate Dependent Plasticity Model for Precipitate Hardened Aerospace Aluminum Alloy Produced with Solid-State Additive Manufacturing,” J. dynamic behavior mater., vol. 8, no. 2, pp. 214–230, Jun. 2022, doi: 10.1007/s40870-021-00325-4.
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M. Y. Rekha, D. Avery, P. G. Allison, J. B. Jordon, and L. Brewer, “Nanostructure Evolution in AA7075 Alloy Produced by Solid State Additive Manufacturing – Additive Friction Stir - Deposition,” Microscopy and Microanalysis, vol. 27, no. S1, pp. 3118–3119, Aug. 2021, doi: 10.1017/S1431927621010783.
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C. J. T. Mason et al., “Process-structure-property relations for as-deposited solid-state additively manufactured high-strength aluminum alloy,” Additive Manufacturing, vol. 40, Apr. 2021, doi: 10.1016/j.addma.2021.101879.
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D. Z. Avery et al., “Influence of Grain Refinement and Microstructure on Fatigue Behavior for Solid-State Additively Manufactured Al-Zn-Mg-Cu Alloy,” Metall Mater Trans A, vol. 51, no. 6, pp. 2778–2795, Jun. 2020, doi: 10.1007/s11661-020-05746-9.
Project Sponsors
