Tinker Air Force Base - Oklahoma City, OK
High Velocity Oxy-Fuel Flame Spray (HVOF) is the newest generation high energy thermal spraying process. HVOF is currently approved for the application of wear/erosion coatings on exhaust nozzles, combustion chambers, and compressor blades. HVOF is currently being prototyped as a chrome replacement on a series of parts.
The main advantage of HVOF over other thermal spray processes is the high impact speed that is obtained by the molten droplets of metal. This high impact speed produces very dense, hard coatings. Many of the properties of HVOF coatings are similar to that of chrome plate. In addition, HVOF coatings can be applied in approximately 45 minutes compared to over 48 hours for the same thickness of chrome. Waste water is virtually eliminated because there are no rinse waters involved. Finally, HVOF is very flexible because one machine is capable of applying over 23 different coatings. The properties of HVOF are being compared to the requirements of different parts to determine prototype candidates. These prototype parts will then be coated and tested in an engine to validate the new coating.
This process allows the plating shop to reduce the amount of chrome plating that is done. It is hoped that HVOF will eliminate approximately 30% of the chrome plating work load. This reduction in chrome plating will also reduce waste water treatment and hazardous waste disposal.