Story ID: 515
MTU Sees Future In Additive Manufacturing 
By: Sean Broderick
Caption: German engine-maker has one AM-made part in service.
Word Count: 376

MTU Aero Engines is investing heavily in additive manufacturing (AM), eyeing both its own products and possible supplier deals with third parties as avenues ripe for growth.

"This is a valuable skill to manufacture and certify these parts," Gerhard Ebenhoch, MTU director, technology management, told AIN last month at the Singapore Airshow. "It's a growing market right now. So we're looking for other opportunities to produce these kinds of parts."

The Germany-based engine specialist first started exploring AM, also known as 3D printing, about a decade ago and has a team of 20 people "and growing" dedicated to AM part development, Ebenhoch said. The effort reached a major milestone last year when it began delivering a part for the Pratt & Whitney PW1100G-JM geared turbofan (GTF) made using AM. MTU, a partner on the Pratt engine, makes borescope bosses out of an AM process called selective laser melting.

The first PW1100G-JMs were delivered with borescope bosses manufactured in a traditional fashion, so the AM part was a replacement on an already-certified engine. MTU eventually wants to design parts that are made using AM from the outset, and the borescope-boss development and certification process provided invaluable experience.

"The biggest challenge—the expensive step and most time-consuming step—is to get the certification of the part," Ebenhoch said. "We wanted to start with this, to enter into discussion with the authorities to see how we could certify the part."

MTU has several other AM-created parts in various stages of development. Some have been tested on a GTF as part of Europe's Clean Sky program. 

While it's hard to say when the next one will enter service, Ebenhoch is confident that the part will be a seal carrier. The high-pressure compressor part, which was tested on the Clean Sky demonstrator engine, has an inner ring that features a complex, integral honeycomb pattern tailor-made for AM. Another benefit of a seal carrier made using AM: MTU would not have to worry about fixing it.

"It's easier to maintain," Ebenhoch said. "You do not have to develop a repair on it, because you don't have to repair it."

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