An In-Situ Cooling Solution for Thermal Spray Coating Process

A cryogenic cooling system has been developed that regulates part temperatures during thermal spraying, eliminating the need for inter-pass cooling breaks associated with traditional air cooling. A mixture of liquid nitrogen and cold nitrogen gas is directed through a nozzle onto the workpiece, with both flows being controlled based on noncontact temperature measurements. In spray trials, coatings were deposited in half the time with greater deposition efficiency, lower porosity, less oxidation and carbon loss, and minimized residual stresses.