With the next generation of suits expected to endure as many as 100 wearings between major overhauls, NASA and ILC engineers have been looking for ways to make a low maintenance suit. To take a key example, the I-Suit's wrist joints no longer need periodic dry lubricant applications. Instead, the glove's designers have coated the joint's stainless steel gimbal rings with a space-tested synergistic coating from General Magnaplate.
Called Nedox SF-2, the coating consists of polymers infused in a nickel-alloy plating, and it plays an important role in protecting gimbal rings from galling and wear. Dave Graziosi, lead design engineer for the I-Suit, explains that the gimbal rings in past gloves required lubrication after just 40 hours of use, while planetary operations will require the I-Suit to function for more like 300 hours without any major maintenance. What's more, the process of applying dry lube to the previous gloves put a big burden on the astronauts. "The gimbal ring had to be removed from the glove because the astronaut didn't want to risk poking a hole in the pressure layer with a syringe," Graziosi explains.
The coating, which has gone into space applications for more than 20 years, provides a more permanent way to protect the gimbal rings. The coating offers a hardness of up to Rc68 and has an extremely low coefficient of friction. Steel against Nedox SF-2, for example, has a static COF of 0.3 and a kinetic COF of 0.26. Nedox against Nedox is even lower with a static COF of 0.18 and a kinetic COF of 0.12. The coating, which is applied at a thickness of about 0.001 inches, also adds some much-needed chemical resistance. Graziosi notes that much of the suit training and testing takes place in chlorinated water that can eat away at metal components.
The suit's titanium brackets and swivels, which form the attachment points for the suit's structural restraints, have likewise been coated with Nedox, Graziosi reports. And space applications aren't the only place Nedox has seen use recently. According to Wayne Cromwell, Magnaplate's general manager, one of the hottest new applications for the coating involves medical fluid analysis equipment. The makers of these machines have been lining up to use Nedox on the rectangular or round platforms that handle the fluid samples. Cromwell says their need to fight wear while eliminating greasy lubes from a medical environment is the key driver in this application. For more information on Nedox and Magnaplate's other coatings, visit www.magnaplate.com .
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| Coatings are improving space suits, including gloves astronauts wear. |