COVID-19 is sweeping across the globe as the decision makers at GE Additive and GE Aviation convene in one of many urgent meetings. Such were the ranging impacts of a pandemic gathering momentum, production was being suspended in GE Aviation factories and external suppliers were making tough calls on which products to discontinue.
It led the services personnel, design engineers and additive engineers in that meeting to have a think about how things could be done differently; how to positively impact their engine programmes when the world was being turned upside down. It led to the production of four land/ marine turbine bleed air components to be switched from casting to metal additive manufacturing.
Despite GE’s renowned history with metal 3D printing, as GE Additive’s Customer Success Engineering Leader Steve Slusher explains, this is not the kind of decision that the company takes lightly.
“The story has to be really compelling for us to switch over traditionally manufactured parts of existing product lines to additive,” he says. “And those factors can be a cost play, it could be a supplier is no longer quoting the parts, so they’re no longer going to make the parts, it could be a yield problem with the current process.”
In this instance, it was a bit of everything. The project was born out of an availability/ sourcing issue, but quickly became a cost play too. Supplying the parts for the LM9000 land/marine turbine to Baker Hughes, GE was able to print four components – all measuring around 3.5 inches in diameter and 6 inches in height – within the same build on a Concept Laser M2 machine. This allowed GE to ‘get our machine hours per part into a very desirable state’ and ensure the parts were cost competitive. Moreover, each component was a one-to-one replacement of the traditionally made part, with no part consolidation and little-to-no redesign. They were also built vertically with only two of the four components requiring support structures, helping to ensure a seamless transition from a casting configuration to an additive one.
“This sounds almost unbelievable for an additive part, but we started with the models for the casting itself and built those internally, processed them and we had very little to no non-conformances based on the geometry coming out of the gate,” says Jeff Eschenbach, Senior Project Manager and Project Lead at GE Aviation’s Auburn facility. “Design did want to do some tweaks to make it a little bit more appropriate to meet their design needs, but they were not wholesale changes, and we were able to accommodate those and print exactly what they want. And the parts looked very good almost first time.”
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Eschenbach is considered the first point of contact when wanting to bring an additively manufactured part into high volume production at GE Aviation’s Auburn site in Alabama. This facility is the ‘high-volume additive facility’ for GE Aviation, with applications being developed elsewhere and passed onto the team at Auburn when deemed ready to go into production. That was the journey the LEAP fuel nozzle tip went on just a year after the Auburn site opened, and it has been the same for many other components since, including these turbine bleed air parts.
With most other production at the site suspended, the project team moved much quicker through post-processing, inspection and ‘getting the application to the finish line.’ They did so inside ten months, while it might previously take as long as 18 months when developing turbine parts, and project cost savings of around 35%.
“The reduction in the design phase enables the additive technology to benefit the business on multiple levels,” offers Kelly Brown, now the Engineering Operations Leader for GE Additive after leading the bleed air component project at the beginning. “It saves cost in the implementation – that’s a simple time and money conversation of less development time, less people working on the programme – but then you really absorb those savings as a business from the minute it’s ready to move forward. So, you look at reduction of costs for the casting itself, depending on which parts can also require less energy, less materials, less plant space, less resources to produce the same parts additively. If you look holistically, those are all good things and that’s how you make the decision.”
Having accelerated the programme during the pandemic, GE is now set to use this project in Auburn as a template with a ‘bank of parts to go after next.’
“Crisis is an opportunity,” says Slusher, “and that’s what we took advantage of down there.”