International Paris Air Show: Safran Announces First EASA Certification for 3D Printed Auxiliary Power Unit Part

French aerospace firm Safran Power Units, which is part of the international high-technology group Safran, specializes in designing and manufacturing power systems for civil and military aerospace. Specifically, its business is organized into two distinct product lines: auxiliary power units (APUs) and starting systems for aircraft, helicopters, and some ground applications, and turbojet engines for missiles and target drones; this makes sense for Safran, which has main businesses in the fields of security, defense, and aerospace. Safran, which has entered into 3D printing partnerships with Amaero Engineering and Prodways Group in the last several months, is joining several other companies, such as Stratasys, Sciaky, and Norsk Titanium, at the International Paris Air Show this week, and it has a pretty big announcement.

Safran Power Units has obtained the first certification for a 3D printed APU major part from the European Aviation Safety Agency (EASA). This milestone certification for a gas turbine nozzle will set Safran in the right direction for eventually achieving mass production.

“Safran Power Units now has complete mastery of the additive manufacturing process, which includes the ability to design differently, while exploiting the optimization potential in terms of industrial implementation. This allows us to offer our customers lighter engine components and reduced manufacturing cycles, whether for new or spare parts,” said François Tarel, CEO of Safran Power Units. “All of our programs will progressively adopt this new manufacturing process.”

The major part that was EASA-certified is the turbine nozzle for the eAPU60, which is often found on Leonardo AW189 helicopters. Safran’s eAPU family offers reduced fuel consumption, the best power-to-weight ratio and dimensions in its category, and improved reliability and endurance. Thanks to its customized design, the versatile eAPU gearbox can be adapted to different electrical systems and power configurations, and is able to simultaneously drive any starter generator and alternator combination; in addition, it also has very low noise emission and pollution levels.

The 3D printed eAPU60 turbine nozzle is manufactured using the SLM process, using nickel-based hastelloy X; it was traditionally machined using inconel casting. The traditional part is comprised of a total of eight components, but 3D printing allowed this to be cut in half to just four components, making the nozzle 35% lighter. Using 3D printing technology to manufacture the turbine nozzle also cuts down on development time – Tarel said that 3D printed components can be manufactured in just days, while expensive machining and tooling equipment must be procured in order to traditionally manufacture metallic parts.

Tarel explained that the certification, which is the result of intensive, high temperature endurance tests on a test bench at the Toulouse site of Safran Power Units, validates the use of 3D technology for manufacturing “engine components that are subject to immense temperatures.”

“It opens the ability to use 3D printing for core engine parts. The quality and certification of this part is very stringent,” Tarel told Flight Global.

Safran’s extensive material testing campaign also helped to prepare the submission of the 3D printed turbine nozzle for certification. The results show that the nozzle’s new design is well-suited for the SLM process, and that its metallurgical properties are in line with the thermal and mechanical requirements necessary for high-performance APU components that must work in extreme conditions.

This year, Safran is expecting to certify similar components in other aircraft APUs, such as the Bombardier’s Global 7000 and Dassault’s Falcon FX. But first, the company will need to make the technology available to the commercial air transport market. Safran is also working to develop hybrid-electric APUs, which are units with both fuel cells and gas turbines; Tarel said that the company expects the hybrid APUs to be available in 2019 or 2020. Discuss in the Safran forum at 3DPB.com.

[Sources: Safran / Flight Global]