New agreement to investigate structural repair of helicopter corrosion with cold spray
November 15, 2011
- Cold Spray technology may save major parts on the UH-60 Black Hawk.
- Center for Cold Spray Research and Development in 2007.
- Cold Spray is a material-deposition process where metal or metal-ceramic mixtures of powders are used to form a coating or freestanding structure.
Cold spray technology that the U.S. Army Research Laboratory (ARL) has perfected is being investigated to save major parts on the UH-60 Black Hawk under a cooperative research and development agreement with United Technologies Research Center (UTRC).
The research focus is in additive manufacturing and the development of cold spray as a structural repair technology, said Victor Kenneth Champagne, Jr., ARL's lead of the Innovative Materials and Processing Team. He said it is anticipated that, in the future, cold spray parts fabricated from nanomaterials and high strength aerospace alloys will be used in the aerospace industry.
Cold Spray is a material-deposition process where metal or metal-ceramic mixtures of powders are used to form a coating or freestanding structure.
"Corrosion reduces strength and lowers safety factor," Champagne said. "Frequent replacement is needed and parts most often do not even meet service and fatigue life requirements, and face logistics and readiness issues for deployed troops. Repaired units will corrode again."
This type of deterioration of magnesium rotorcraft parts, like gearboxes on Army and Navy helicopters and Air Force fighter jets, is a major sustainment problem along with other magnesium parts within airframes which have to be removed prematurely because of corrosion. Many of the parts cannot be reclaimed because there is not an existing technology that can restore them adequately for service.
That could mean 20 to 30 parts per aircraft, or almost 5,000 helicopters affected between the Army and Navy, or 20 percent of the fleet, he said.
"These parts are highly susceptible to corrosion and fretting wear resulting in significant unscheduled maintenance actions and high replacement costs of more than $800,000 each," Champagne said.
The Army and Navy spent $17 million in one year for UH-60 main transmission and tail rotor gearbox housing assemblies. The Corpus Christi Army Depot has millions of dollars of used magnesium housings waiting to be reclaimed as part of the Storage, Analysis, Failure Evaluation and Reclamation program. As a structural repair technology, Champagne said, cold spray could be used to reclaim these parts and save the military on acquisition costs as well.
ARL established the Center for Cold Spray Research and Development in 2007, which remains the only Department of Defense facility to have research and development, production and field-repair capability in Cold Spray. Major military and commercial successes include the repair of magnesium on aircraft parts.
Sikorsky aircraft systems like the UH-60 Blackhawk, repair of titanium hydraulic lines for B1-Bombers at Tinker Air Force Base, Okla., and near-net forming of shaped charge liners and sputter targets for Benet Labs, Watervaliet Arsenal and H.C. Stark.
This latest project with UTRC was established as part of Champagne's role as a liaison to the Natick Soldier Research and Development Center, he said.