Twenty parts were once machined together to construct part of the CFM Leap engine. Now there's only one piece—and it's five times stronger.
The bestselling aircraft engine General Electric ever conceived is one that doesn’t enter production until later this year and is considered the first passenger jet engine to use 3-D printed fuel nozzles.
Close to 8,000 orders valued at more than $80 billion have been placed for GE’s new Leap engine, currently being developed by CFM International, a joint company with split ownership between GE GE and France-based Snecma. While its capitalistic credentials are noteworthy, it’s the 3-D printing process—otherwise known as additive manufacturing—by which the engines’ fuel nozzles are produced that make the Leap a cut above. Every Leap engine contains 19 nozzles, each of which has to withstand temperatures up to 3,000 degrees Fahrenheit. And where 20 separate parts were once machined together to construct the nozzle’s interior passageways, there is now only one piece built up by a layering of powdered metals melted and fused together through a direct metal laser melting, or DMLM, process—making each nozzle five times stronger than those made through milling, welding, and other subtractive manufacturing processes.
“I think what additive gives us is a whole different degree of freedom on how we think about component design,” says David Joyce, CEO and president of GE Aviation. “We no longer have to understand what the limits of machining are.”
Indeed, GE is making a big bet on additive manufacturing, in large part because of the new Leap engine: By 2020, GE Aviation will be manufacturing well in excess of 100,000 parts via additive manufacturing for the Leap and other aircraft engines. The company, which cleared revenues of $22 billion in 2013, plans to make a $3.5 billion investment in additive manufacturing over the next five years. Some of that push is to bring about cost-savings in the manufacturing process. The other part: build out factory and employee capacity to create a wider suite of engine components that can’t be machined through traditional manufacturing processes.
“The real power of additive is taking six parts and designing it into one. You can create geometry that you can’t make it any other way,” says Greg Morris, the business development manager of additive technologies at GE Aviation.
Not to mention having the ability to test a design, fail quickly, and re-test a new design quickly. “You can iterate quickly, find out what’s working and not working, change designs, and you can do that many more times than what traditional technologies would allow people to do in the past,” says Morris, who says it took about 50 different iterations to finally have a working Leap engine fuel nozzle design.
So what does GE’s big push into additive manufacturing look like? Part of it is a $50 million investment that started last year to beef up a production facility in Auburn, Alabama, by installing hulking 3-D printers—like those produced by worldwide e-manufacturing company EOS—and hiring as many as 300 full-time employees. That’s in addition to the close to $140 million GE has invested into its GE Aviation Additive Development Center near Cincinnati, Ohio. Formerly Morris Technologies, GE acquired the company in 2012 to lead its push into an additive future.
It was Morris Technologies that began working in secret with GE early last decade to 3-D print a fuel nozzle for the Leap engine. Today, close to 90 people are employed by GE Aviation in Cincinnati, a number that stands to increase rapidly over the next several years, doing prototyping and low-rate initial production on a variety of 3-D-printed parts, including the Leap engine’s fuel nozzle. Once a fully tested part looks like it’s headed for general production, the GE Aviation team in Cincinnati does an initial slug of production-quality components, and then hands off their work to the additive manufacturing team in Auburn.
“That’s the end game,” says Morris, who joined GE after his eponymous 3-D technology company was bought three years ago. “From an additive perspective, the [Leap] engines that are going to enter the service in the next few years here are going to have the fuel nozzles be the additive component in those engines. As time goes on and we get a little further along in material characterization and geometry, we’ll probably find other parts that we can add into engine.”
As for cost-savings, Morris says that’s a story “still being written,” and probably won’t be fully understood by the company until the early part of the next decade. “We’re in the ramp process, although we’ve made thousands of parts,” he says. “When we’ve hit full capacity, that’s when you get a good idea of cost reduction.”