Additive Manufacturing. We believe in both halves of that term. Additive processes offer engineering possibilities that go beyond machining and other methods. And the future of those processes is manufacturing functional tools and parts.
Issue link: https://am.epubxp.com/i/62900
T he Boeing Company's Additive Manufactur- ing R&D; group in St. Louis, Missouri makes prototypes practically every day. The group is a prototyping resource for the entire company. On the day I visited, one of this team's additive machines was generating prototypes for helicop- ter components being designed in Philadelphia. CAD data would arrive in St. Louis and the cor- responding plastic part would ship out less than 24 hours later. This same group also makes fixture tooling. A rapid-response machine shop within the same building as the additive group is dedicated to making replacement parts for planes. Additive manufacturing often provides the fastest way to create a custom fixture for one of these one-off jobs. However, neither prototypes nor tooling repre- sent the true potential of additive manufacturing. Michael Hayes, principle design engineer with the Additive Manufacturing group, says that ad- ditive manufacturing processes need to go—and will go—far beyond their established applica- tions. These processes that build complex forms layer by layer offer considerable promise not only to eliminate assembly steps, but also to reduce weight from aircraft designs in which every pound is important. One of his group's responsibili- ties within Boeing is to help realize exactly this potential by finding cases in which additive man- One strength of additive manufacturing is its ability to generate parts with complex internal channels. Ductwork for the F/A-18 Hornet (facing page) has been produced on additive equipment for years. Another issue is accuracy. In metal, the precision of additive processes is not yet sufficient to pro- duce a part that can meet tight tolerances without further processing. Yet neither of these challenges is among the most critical constraints, the two men say. Further process innovation and refinement of the additive machines can clear these hurdles. Instead, the more confining constraints to the ap- plication of additive manufacturing today are much simpler. Namely, (1) the machines are too expen- sive and (2) the machines are too small. Dietrich elaborates. He says the purchase price of an additive metal part-making machine is high enough that it forces him to seek only certain May 2012 — 5 ufacturing might be the best process for producing an end-use component for the finished aircraft. To be sure, there are obstacles to applying additive manufacturing as a production process in this way. Those obstacles might not be what you would expect. Hayes, as well as David Dietrich, an engineer in the group who focuses on metal addi- tive processes in particular, says that control over material properties is certainly an important issue. Additive processes do not yet offer the part-to- part consistency that critical aircraft parts require. The Boeing group in St. Louis received an order for these inlet ducts related to a high-altitude aircraft. Two days later, the plastic parts had been additively manufactured (also painted), and were ready to be shipped out for engine testing.