Directed energy deposition (DED) additive manufacturing (AM) proceses can be used to repair aerospace components, extending their life-times and reducing through-life costs. Technical and commercial challenges include variation in equipment and processing capabilities and the properties of the material produced. AM material can be stronly anisotropic becaue of they way in which is it deposited. This means that before it can be used for safety-critical components we need to better understand the effect of DED processes on the structural integrity of repaired components.
A large part of the work carried out in AMOS is the characterisation of DED materials manufactured at partner facilities:
- ECN - depositing Ti-6Al-4V using a laser and powder system
- Liburdi - depositing Ti-6Al-4V using a laser and wire system
- McGill University - depositing Aermet 100 using a laser and powder system
- University of Sheffield - depositing Inconel 718 parts using an arc and wire system
- University of Sheffield - depositing Inconel 718 using a laser and powder system
All tests carried out in the project are done to the relevant ASTM standard and include:
- Visual and dimensional checks (visual / metrology )
- NDE (CT-scans and fluorescent penetrant inspection)
- Macro- and micro-analysis (microstructural analysis, porosity)
- Chemical analysis (XRF)
- Mechanical testing (tensile, low cycle fatigue, crack propagation)
Tests were done on the substrate, the as-built material, and the substrate / AM material interface. Results for Inconel showed that wire-deposited materials showed better tensile properties than the powder-deposited material, for both the as-built material and the interface region.
For titanium wire, yield stress, ultimate tensile strength and elongation are comparable with the standard reference material. However, when using powder, the results were below those of the reference standard.
The investigation into Aermet 100 is ongoing.
The majority of the tests have been completed, although work is ongoing on low-cycle fatigue and crack propagation.
For a full list of test results, please contact us.