GE is also investigating the possibility of printing some airplane parts, a strategy EADS has also recently pursued. At the EADS labs in Filton, U.K., researchers demonstrated that they can print out several different metal parts for airplanes with a technology that uses a laser to heat metal powders until they form solid metal shapes. Using this technique, EADS has printed metal hinges for engine covers: the hinges allow the covers to swing open for engine maintenance. The parts have intricate shapes that maintain strength while cutting the weight of the part in half. The new hinge has been put through the tests used for conventional parts and shown to meet performance requirements. Weight savings are critical in the aerospace industry. According to EADS, reducing the weight of an airplane by just one kilogram can result in fuel savings of $3,000 per year, or $100,000 over 30 years—the typical life of an airplane.
To be sure, the technology is still limited. Although many functional metal alloys can be printed, the high-performance ones used inside an engine can’t yet be produced in this fashion (such parts require a level of precise control over the temperatures of the materials during processing that can’t be achieved yet in printing). GE will use the new technology to print out engine parts—such as turbine blades—but only for testing certain properties of a design, such as its aerodynamics, and not its ability to survive high temperatures and pressures. Singh says that this could help speed up the design process by making it possible to have a high-precision part built in weeks rather than months.
The other main limitation of the technology is the size of the objects it can print. Depending on the material and the printer, it’s possible to print things that are a few centimeters across to at most something near a meter. Printing out wings or parts for some of GE’s large power-plant turbines is still not possible. And there are some things that likely will never be made using three-dimensional printing. “It will never be used to make something such as nails. But eventually it could be used to make the tools that make nails,” says Jonathan Meyer, a research team leader at EADS Innovation Works.