High Velocity Oxygen Fuel (HVOF) is a thermal spray coating process used to improve or restore a component’s surface properties or dimensions, thus extending equipment life by significantly increasing erosion and wear resistance, and corrosion protection.
Molten or semi-molten materials are sprayed onto the surface by means of the high temperature, high velocity gas stream, producing a dense spray coating which can be ground to a very high surface finish.
The utilisation of the HVOF coating technique allows the application of coating materials such as metals, alloys and ceramics to produce a coating of exceptional hardness, outstanding adhesion to the substrate material, and providing substantial wear resistance and corrosion protection.
As the technology specialists in HVOF coating, Bodycote provides an array of spray coating materials to suit your specific needs. Backed by a customer-driven service, our facilities process a wide variety of component sizes to exacting standards with reliable, repeatable results.
High Velocity Air-Fuel (HVAF) is a more recently developed thermal spray process: HVAF is a “warm spray” process that is cooler than HVOF guns (due to utilization of axial powder injection into an air-fuel jet with a temperature of about 1900-1950°C) and therefore, the process is capable of effectively applying carbide-based materials, but since the air-fuel jet produces considerably less oxides than high temperature oxy-fuel jets, the HVAF process can also apply metals with almost zero oxidation (similar to Cold Gas Spray technology) . All common thermal spray powder materials may be applied with HVAF, except for ceramics,
for deposition of coatings for protection of parts, vessels and structures against abrasion, erosion and corrosion.
Coatings deposited with both technologies have the following common uses:
Thermal spraying process by HVOF will be optimized for green carbides and spraying procedures will be extended to other methods, as CSG and HVAF.
A proper coating process permits indeed to save time, money, labour on maintenance and replacement thus reducing industry operating costs.