by Dale Moody, Peter Foy | Jun 22, 2017
Combining the Two Processes
HVAF and HVOF have been merged into a single system (HVAF/HVOF) that offers the highest spray rates in the industry in either mode. The HVAF/HVOF thermal spray system uses air as the primary oxidizer and oxygen to elevate the temperature, thereby optimizing the process with breakthrough results. The addition of oxygen provides all existing HVOF owners and new prospects a reliable and less expensive coating with a high quality. Existing HVOF specifications can be achieved and exceeded using the convertible system. Users can achieve a 0.002-in. thick corrosion-proof coating that holds up under high pressure and can be polished to an RA 4 finish without grinding.
In comparison to the HVOF process, the combined process provides a significant increase in the Vickers Hardness of WC-10Co-4 Cr coatings. Weight loss during silt erosion testing is less than 1/3 of the weight loss of the same coating applied with the traditional HVOF process. Furthermore, the cost per kilogram deposited can be as much as half that of using the HVOF process.
In summary, the HVAF/HVOF system produces very economical, high quality coatings with easy to use, reliable equipment.