GE Aviation’s Loyang, Singapore, facility has become the first MRO facility worldwide to have been approved to use metal additive manufacturing for commercial jet engine component repairs.

GE Aviation Engine Services Singapore (GE AESS) accounts for more than 60 per cent of GE Aviation’s global repair volume.

The company noted the increasing use of metal additive technology in the design and industrial production of new aerospace components. GE said 3D printed parts were typically printed using STL files generated from CAD drawings, but that this only works for new-make production where the goal is to produce identical parts conforming to the blueprint. When repairing used parts, the company said, the repair has to be customised for each individual part because each part wears differently during service.

Additive technology in repairs also offers the possibility of embracing complexity, rather than shying away from it, GE added.

“This disruptive technology can be used for lots of applications, not only in aviation,” said GE AESS’ executive manufacturing leader Chen Keng Nam. “When I see beyond the realm of repair into new-make, it’s mind-blowing to see the parts that we can design and print using additive. Now designers are making use of the ability to produce new designs that couldn’t be imagined or manufactured before with traditional methods.”

GE AESS’ managing director Iain Rodger said metal additive technology has big potential in MRO. “In this part of the supply chain our customers truly value faster turnaround time, and that’s what we are achieving,” he said. “Using our GE Additive Concept Laser M2 machines typically halves the amount of time it takes us to repair these aircraft parts.”

Rodger said his teams are already using additive technology to repair parts in GE Aviation’s CF6 engines. The company next aims to include parts on the CFM56.

One example is the repair of high-pressure compressor (HPC) blades that run at high speeds and tight clearances within aircraft engines. They face regular erosion and wear and tear that, over time, demand continuous repair and replacement, GE said.

“Repairing these blade tips used to require a long process of cutting, welding and grinding to create the proper shape,” the company stated. GE Aviation has established an automated additive manufacturing process to repair the HPC blade tips, saving time and costs associated with labour and machining. The company created image-analysis software that maps the shape of a used blade and creates customised instructions for the Concept Laser M2 machine to build a new tip with precise alignment and profile. “The 3D printed part is near-net shape and can be finished with minimal additional processing,” GE added.

Rodger said: “Productivity has increased with our employees able to repair twice as many parts in a day compared to the conventional repair process. Less equipment is also needed for post-processing so the floor space required is reduced by one-third.

“Further to that we are currently assessing what we are going to do in turbine parts and other components beyond compressors. Day-to-day, working with customers, they will know that there’s a difference as they will be seeing their parts return to them more quickly.”

The technique will also aid GE’s sustainability aims. “This is going to allow us to repair more parts and throw fewer parts into the bin, use less energy, generate less waste and have a smaller footprint,” said Rodger. “Repair capability is a big part of the sustainability journey. As the industry expands and new technology is developed, that will only increase.”