While 3-D printing applications in aerospace remain limited to relatively small and simple parts, Honeywell engineers believe the technology carries potential in the manufacturing of a critical engine component: turbine vanes.
“To create a single ceramic turbine vane core, you must first create a giant metal mold for it,” explained Wil Baker, principal engineer of advanced technology at Honeywell. “That tool is extremely expensive, and may take a year to 18 months to manufacture. By 3-D printing the core, however, in one shift we can produce a couple of dozen or more cores—and thousands in a week.”
Another significant advantage of high-resolution 3-D printing over injection molding is its ability to form crisp surface features, including perforations, at the time of printing—avoiding the need for final hand finishing or machining of parts.
While Honeywell's program remains in the development stage, Baker noted the company has already seen comparable finish quality from 3-D-printed components. “Now we can create much higher-resolution features, which enables us to make much higher-performance designs,” he added. “From the standpoint of a new engine design, the progress of an entire program is often paced by the production of these parts. We may scale down the design cycle by many, many months."
In addition to condensed development times for new engines, Baker noted that perhaps the greatest potential for 3-D printing technology lies in speeding the release of improved versions of existing components.
“There's a huge reluctance to change a core mold because of the time and expense involved,” he said. “3-D printing doesn't care whether it's printing something simple or complex; there is no cost difference. When combined with the inherent time savings, the technology promises to speed introduction of much higher-performance designs and get them into service without a significant cost factor.”
While acknowledging that challenges remain in honing the process, and noting that the industry likely remains years away from seeing such components manufactured through 3-D printing techniques, Baker sounds bullish about the possibilities.
“We've cast a host of parts successfully that meet requirements, and our next step is certification,” he concluded. “We definitely see the light at the end of the tunnel.”