We partnered with the Midlands Aerospace Alliance (MAA) and the Manufacturing Technology Centre (MTC) on their Digital Reconfigurable AM Facilities for Aerospace (DRAMA) project to develop short lead-time AM porotypes of aftermarket parts. We wanted to understand if it were possible to replicate products in AM that could replace subtractive manufactured parts and speed up the lead time. Before investing a 3D printer, we wanted to know what the capabilities and benefits were.
We engaged with the DRAMA project to understand the benefits of using a metal additive manufacturing (AM) process to produce rapid high integrity aerospace part prototypes to aid in the design of fixturing for conventionally machined production parts. By using AM for prototyping a part, we could significantly reduce prototype lead times and offer improved delivery for production parts. Getting a prototype faster gives sufficient time to refine the fixturing and work holding so that the production parts are consistently compliant. In addition, the costs of producing customised tooling for prototyping with subtractive manufacturing are eliminated.
NCAM engineers visited AE Aerospace to gain an appreciation of the products currently manufactured and the processes involved. After initial assessment, two components were identified as the potential best candidates for rapid prototyping with AM and a representative Clevis component was developed by AE Aerospace to proceed to the next phase using Inconel 718. Whilst considering the material, geometry, and surface finish requirements, it was deemed technically feasible to manufacture a prototype of the Clevis using Laser Powder Bed Fusion (L-PBF) and Hybrid L-PBF AM technologies. However, surface finishing and finish machining operations would be required with L-PBF to get to the required tolerances and surface finish. Whilst with Hybrid L-PBF only finish machining would be required on specific regions . For both processes the cost of manufacturing is higher compared to the current process but the lead time can be reduced from 3.5 months to less than two weeks.
Based on this understanding, Phase 2 activities were launched to build, inspect and test AM parts. Once built using a Matsuura Lumex 25 Hybrid LPBF machine AE Aerospace observed that some further development work would be required to achieve the required surface finish and dimensional accuracy for the representative Clevis component. The IN718 component incurs high tool wear and was difficult to machine in the presence of powder causing machining marks, whilst residual stresses inherent with the LPBF process resulted in movement of the component during machining and a loss of tolerances.
Although this project finished with a number of questions still unanswered, we have seen enough promise in this project to pursue the AM prototyping route. The next phase of work will include further builds to assess different build and machining strategies, alongside a detailed assessment of the business case for using hybrid laser powder bed fusion. Completion of these activities will allow AE Aerospace to determine if this this technology is viable process for the manufacture of prototype components.
We recognise that we have just begun our additive manufacturing journey. We purchased a Flashforge Guider 2 3D-printer. We have utilised it to print fixtures for our Mazak machines but also used it to print prototypes of our components. Sometimes it can be difficult to visualise a component from a drawing. As a result, we design them on Fusion 360, allowing us to check the design and make any modifications before being programmed to our machines and manufactured correctly. We have found that this helps us reduce our waste and has increased our OEE.
Having a 3D printer has got our team using the phrase ‘if we don’t have it, let’s make it!’. As such we have also designed and created fixtures that keep our products intact during delivery, as well as creating bespoke tool stands for our technicians. For instance, we created these holders for some of our components to prevent our technicians’ hands getting sore, instead of filing one at a time they can now do 4 at a time.
It is allowing us to think innovatively, and we look forward to venturing further into AM.