The US Naval Seas Systems Command (NAVSEA) 04 Ã 3 Tactical Innovation Implementation Laboratory (TIIL) has led the development of a novel cold spray technique, which can improve the routine maintenance of vessels and extend the life of components of older vessels.
The cold spray process works by jetting a combination of metal powder and inert gas – usually hydrogen or nitrogen – onto a component of a ship at supersonic speed. The impact flattens the particles and welds them to the component, essentially creating a whole new part, extending its lifespan by several years.
Cold spray refers to the low temperature at which the bonding process occurs, normally 212 Â° F to 930 Â° F. Traditional welding methods start at around 5,000 Â° F.
It is the high speed at which the powder is pulled over the component that causes the sticking, not the high heat, which means that the metallurgical properties of a part are not distorted or damaged. Cold spraying is also useful for bonding more brittle non-metals, such as ceramics.
TIIL Director Janice Bryant said, “This process allows us to take something worn out and reconfigure it into something new.”
TIIL cold sprint
From January 15-16, TIIL conducted a Cold Spray Sprint exercise to advance the implementation of cold spray in ship maintenance, at the Advanced Technology Innovation Center of the US Naval Undersea Warfare Center (NUWC) of Keyport in Washington State.
TIIL designed the sprints as quick events focused on accelerating the delivery of cold spray to shipyards.
Bryant added, âThe sprint is not a meeting or a task force. It is work and actions required to transition from technology creating new capabilities to operate ships.
Representatives from four US Navy repair centers, Naval Air Systems Command and the US Coast Guard, as well as senior civilian scientists, took part in the exercise.
âWe have reached the limits of efficiency on older processes. Our main goal is to restore the material and extend the longevity. “
NUWC Keyport chemical engineer Brian Dougherty, who was present at the exercise, said the main benefits of cold spraying are faster maintenance work times and reduced costs of reusing vessel components.
âWe have reached the limits of efficiency on the older processes,â said Dougherty. âOur main goal is to restore material and extend longevity. ”
Associate Mechanical Engineer Alex Frank, who works in the NUWC’s Rapid Prototyping and Manufacturing Technology Division, added that the cold spray technique can outperform traditional welding jobs and has several other uses, such as replacing “brush plating and epoxy repair”, which involves hazardous chemicals. and can take days.
TIIL noted that cold spray maintenance could be performed in the future by an articulated robot, which could be sent into space or onto a ship or submarine, to complete repairs much faster than crews. humans.
US Navy engineers have already demonstrated a cold spray additive technique as a novel approach for naval aircraft repairs.