Avio 3D-printed turbine blades
Avio 3D-printed LPT blades for the LEAP, GEnx, GE90 and GE9X jet engines.
In the US, today marks National Aviation Day; the day of Orville Wright’s birthday and a day to celebrate all that is great in aviation development. Thanks to additive manufacturing the aviation industry is having some of its most significant developments in decades as the technology and the understanding of it advances at an extraordinary rate.
The partnerships between machine manufacturers and users grows ever more important in achieving the standards needed for it to be adopted fully into the aerospace industry. Back in January we brought you news that Swedish Electron Beam Melting (EBM) specialist Arcam had revealed that they had received an order from a "major aerospace industry client". They have been working with this client to achieve a pretty substantial breakthrough in the 3D printing of lightweight metal blades for jet engine turbines.
The client, it appears, was GE Aviation and in particular their 2013 Italian acquisition Avio Aero. Avio have used the Arcam EBM technology to build titanium blades from layers of powders that are more than four times thicker than from other 3D printing powders.
This process for manufacturing eight "stage 7 blades" for the low pressure turbine that goes inside the GEnx jet engine completes in just 72 hours. “This is very competitive with casting, which is how we used to make them,” says Mauro Varetti, advanced manufacturing engineer at Avio.
The advanced aerospace material titanium-aluminide (TiAl) produces blades that are 50% lighter than the nickel-based alloys typically used in the manufacturing of these blades and can reduce the entire low-pressure turbine by as much as 20%. “Although the material is expensive, the weight savings and the fuel consumption savings tied to weight reduction more than pay for it,” Varetti says in the GE Report.
Though TiAl is usually difficult to work with and is prone to cracks and imperfections when using a more traditional manufacturing method, the EBM process solves these issues by allowing the engineers to control the properties by preheating the powder.
EBM machines are now working inside Avio’s new 20,000-foot plant near Turin, Italy. The factory, which is dedicated to additive manufacturing, opened last August. Later this year, GE will start testing these printed blades for the GEnx engine at its test facility in Peebles, Ohio with view for them to go inside the new GE9X jet engine that GE is developing for Boeing’s next-gen long haul plane, the 777X.
2013 TCT Show speaker and leader of GE’s AM programmes, Greg Morris said he can think of dozens of jet engine parts that could be 3D printed and finished up on this Aviation Day by saying “ The sky is the limit.”