Navy Valve Actuator Repair Using Cold Spray

Cold spray is a reduced temperature, supersonic thermal spray process that is increasingly being used to perform repairs on high value components.  In this case, a valve actuator internal bore sealing surface was repaired on an aluminum 6061 hydraulic valve body using high pressure cold spray for the Navy.  Corrosion damage to non-critical surfaces was also repaired, allowing the part to be returned to service.  The cold spray process was applied with a VRC Gen III high pressure cold spray system using a gas atomized 6061 aluminum powder.  The internal bore surfaces were approximately 100 mm in diameter with a depth of nearly 200 mm, and were sprayed using a 45-degree nozzle 65 mm in length.  The requirements for adhesion on critical surfaces of a minimum of 69 MPa were exceeded with an average of 75.7 MPa, with glue failures on ASTM C633 bond test specimens.