For 30,000 years, people have been making things from fired clay: from dolls in a paleolithic Czech village to delicate china sets, and, more recently, ceramic bone implants and space shuttle insulation. Ceramic is harder and lighter than steel, resists corrosion better, and handles more heat. But you won’t find an engine made out of it. Hit it with a hammer and it shatters.
That’s about to change. Scientists at GE Global Research (GRC) teamed up with designers at GE Aviation and developed a new kind of ceramic that outperforms the most advanced metallic alloys. The material, called ceramic matrix composites (CMCs), handles the punishing forces and heat as high as 2,400 F inside gas turbines and jet engines, and makes them much more fuel efficient. “Our materials have the strength, durability and manufacturability that other ceramic composites lack,” says Robert Klacka, technology marketing manager at GE Ceramic Composite Products. “I don’t know if I would have said it 10 years ago, but I can say it now. I’ve seen it.”
But inventing a new material means that you also have to to design the machines to manufacture it. The machines, developed at the GRC, first give ceramic fibers a special coating to make them durable, form them into tapes, and cut them into panels of desired shapes. The panels are then fused in a furnace. The process is producing parts like turbine shrouds, combustor liners, turbine blades, and fairings for gas turbines and jet engines, including the new LEAP engine.
Materials like CMCs and the methods to make them will be on the agenda of the day-long GE Works: Advanced Manufacturing summit held tomorrow in Washington, D.C. “Manufacturing excellence forgotten for too long is once again a competitive advantage,” said Jeff Immelt, GE chairman and CEO.
Laser Vision: A laser beam welds super alloy metal powder layer by layer to create the final part. This 3-D manufacturing process is called direct metal laser melting (DMLM).
The new LEAP jet engine made by CFM International, a joint-venture between GE and France’s Snecma, is a good example. Besides ceramics, the engine includes parts “printed” by a laser that sinters ultra-thin layers of metallic powder to make the desired shape.
This process is called “additive manufacturing,” or 3-D printing. Traditional “subtractive manufacturing” like milling or drilling cuts away material. Additive manufacturing allows companies to print parts from a digital file by depositing one layer of material layer on top of another, to obtain complex component shapes that have been traditionally difficult to make. “It’s one of the biggest things to happen in manufacturing in some time,” says engineer Luana Iorio, who leads manufacturing research at the GRC. “You give the designers a completely new freedom. They are not bound by the constraints of traditional manufacturing. They can really strip down products to the core of what it is they need them to do.”
Iorio’s team, which includes material scientists, mechanical, manufacturing and software engineers, chemists, physicists and other GE experts is now developing design applications to harness the method’s full power and print more parts faster. “How can we make the parts bigger and the material properties more reliable?” Iorio says. “This is very much a multi-disciplinary effort and I think this is what gives us an edge in this space.”
GE estimates that by 2020, there will be some 100,000 printed parts inside GE and CFM engines. “We may not fully realize it yet, but we are at the dawn of the next Industrial Revolution with additive manufacturing,” says Michael Idelchik, vice president of advanced technologies at the GRC. “It has the potential to fundamentally disrupt how complex products like jet engines are designed and made in the future. And we believe that the U.S. is well positioned to lead the way in its growth and development.”