TREND #1: The Composite Problem
Boeing’s 787 Dreamliner represents one of those rare game-changing technology advances, at least in terms of its material construction. The fuselage is composed of an innovative composite fiber tape that is wrapped around the plane’s skeletal structure for added strength and durability with some impressive weight reductions.
This design—and all of the problems it presents—perfectly encapsulates one of the prevailing issues facing machine builders bringing products to IMTS this year: Aerospace companies are adopting newly engineered materials that are simply too hard and too resilient for traditional machine tools and traditional tooling processes to handle.
“It’s engineers gone wild,” says Scott Walker, president of machine tool builder Mitsui Seiki U.S.A. “They’re coming up with stuff that is extremely difficult to machine and grind and make into finished products.”
With the new generations of aircraft coming from Boeing (IW 500/16) and Airbus and the recent advances by the private space-transport sector, the demand for these difficult-to-machine materials is growing dramatically, he says.
As it does, it is driving advances in machine tool technology to provide precise, high-speed machining for parts built for unparalleled strength and durability.
“Customers are facing the fact that these materials are becoming harder to machine, harder to mill and grind,” says Patrick Redington, Saint-Gobain Abrasives director of application engineering, North America. “The issue we all face is that cutting tools grow dull very quickly when machining these harder materials, which can lead to part fracture and failure. It affects productivity and makes tooling costs go through the roof,” he explains.
Taking on this challenge, Mitsui Seiki will be exhibiting its HU100A-5XL HMS—a heavy-duty five-axis machine used for structural components on the Boeing Dreamliner and Airbus’s 320 and 340 jets, among other aircraft.
“The machine is designed for machining these hard, resilient materials,” Walker explains. It does this by emphasizing machine rigidity, stiffness and accuracy, three essential characteristics that machine builders require to compete in the growing aerospace industry.
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| Mitsui Seiki's U100A-5XL. High Performance Machining Center emphasizes machine rigidity, stiffness and accuracy for machining resilient materials. |
The Dreamliner illustrates this issue, too. The 787 fuselage comes in as eight very large, very expensive and very difficult to machine pieces. Machine tools lacking rigidity, stiffness and accuracy trying to process these pieces can result in some expensive mistakes.
“The fuselage for the 787 is a very costly part to scrap,” explains Mike Judge, vice president of Cryogenic Business Development at MAG. “Boeing is not necessarily interested in an increase in processing speed for these. They’re more interested in keeping the tool sharper longer to avoid scrapping their parts on the machine.”
To avoid those costs, he says, machines need to increase tool life to ensure sharpness and accuracy and increase processing speeds.
A prominent contributor to this field that will be appearing at IMTS this year is MAG and its Minimum Quantity Cryogenics technology.
This emerging technology breaks ground in the hard-to-machine composite market by plumbing liquid nitrogen through its spindle and through the cutting tool itself to cool the machining process. The heat-sink effect in the cutting tool makes possible a rapid increase in processing speeds and dramatic extension in tool life when dealing with these composite materials—two reasons that Boeing uses cryogenic technology for trimming and drilling its Boeing 787 fuselage.
