This Phase I effort will try to develop a method for repairing damaged IVD aluminum coatings instead of the brush cadmium plating currently used by Navy. Due to the toxic nature of cadmium, the new method with non-hazardous operation procedures mainly consists of cold spraying and shotpeening (CSS) by using aluminum as the coating material, which includes the steps of: (1) damaged area cleaning by sandblasting; (2) coating preparation by cold spraying specially processed aluminum powders; (3) shotpeening the coated area to densify the coating; (4) thickness correction and chromate conversion coating if necessary. The new coating will meet or exceed the performance of the coating it repairs, and has a good bonding strength with the substrate and adjacent material, and also provide an adhesive base for subsequent organic coatings. In order to realize this method, an apparatus will be designed and fabricated during this Phase I project. The apparatus is a compact and integration system, containing three functions: sandblasting cleaning, cold spraying and coating densification. It is also lightweight and easy to transport to any place where the repair is needed. The whole repair process will be done in a few minutes, depending on the size of the damaged area.
Benefit: The proposed CSS method and apparatus with integration and compact features have a wide variety of defense and civilian applications in coating formation, including damaged coating repairing on warship, fighters, military vehicles like tanks, commercial aircraft, reactor vessels, toxic or corrosive material storage or transportation tanks, synthesis tower or pipes in chemical plant. It also can be used for restoration of lost metals like cracks, cavities or caverns in steel or cast-iron castings, mechanical damages of bearing seats, pump bodies; and fixing leaks liquids and gases where there is no opportunity to use hermetic compounds. The high electrical conductance of coatings adhered to any metal or ceramic surface by using this method provides their effective application in different electronic or electric components. Furthermore the method will be used for prime layering for soldering, sealing of welding seams, sealing of high pressure pipe-line junctions, functional coating for increasing heat radiating ability of stainless steel, anti-blocking coating of bolts, and auto service.
Keywords: IVD Coating, IVD Coating, CSS method, Cold Spay, Brush Plating, repair, Nonhazardous Pollutant, Cadmium Replacement
