The U.S. Navy has received certification for a technology that allows worn or damaged metal components to be restored without traditional welding. The technology is known as cold spray, a process in which metal powder is propelled at high velocity using pressurized and heated gas and applied to a damaged surface without melting the base material.
The technology was certified for Naval Undersea Warfare Center Division, Keyport following approval by Naval Sea Systems Command (NAVSEA). Keyport became the second U.S. Navy warfare center to receive this approval.
Because the metal does not melt during cold spraying, the process does not cause component deformation or damage to the surrounding area that can occur due to the high temperatures involved in welding, according to DVIDS.
One area of focus for Keyport is three-way ball valves, whose repair is one of the causes of delays during submarine maintenance.
Naval shipyards currently use epoxy to restore eroded or corroded areas of these valves. During curing, the epoxy can crack or lose adhesion to the metal. When this happens, the failed repair must be removed in an oven and the process started again.
Keyport engineers conducted tests to compare this process with cold spray. According to their estimates, using cold spray to repair the valves could reduce repair turnaround times by 9–15% and cut the number of repair attempts by up to 42%.
Keyport specialists are also developing standardized cold spray procedures for naval shipyards and repair facilities. These procedures will define the spray parameters and automated robotic movements required to repair specific components.
The technology is also planned for use on larger components. Keyport intends to move its equipment to a larger facility to work on components including submarine masts and radar shafts.
Separately, NUWC Division, Keyport is working with Naval Nuclear Laboratory to develop structural cold spray repairs for pressurized piping systems. The technology could allow pipes to be repaired without isolating, draining and cutting out damaged sections.
Keyport is also working on a real-time nitrogen generation system that would support 24-hour operation of the cold spray equipment.
