HVOF Tungsten Carbide Coatings
HVOF Tungsten Carbide Processing
High Pressure Piston Diamond Grinding
Tungsten carbide is a chemical carbide containing equal parts of tungsten and carbon atoms. It is approximately twice as strong as steel with double the density and is double the density of steel—nearly midway between that of lead and gold. Tungsten Carbide’s hardness level is comparable with corundum and can only be polished and finished with abrasives of superior hardness such as cubic boron nitride and diamond powder, wheels, and compounds.
In its basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery, cutting tools, abrasives, armor-piercing rounds, other tools and instruments.
Tungsten Carbide Coating Benefits
The HVOF tungsten carbide thermal spray process produces tremendous amounts of kinetic energy into the powder particles. When these highly energetic particles strike the substrate, their velocity drops to zero and they absorb their kinetic energy, which causes them to bond instantly to the workpiece. Subsequent particles arrive almost simultaneously, rapidly building up the coating. This results in very dense, very adhesive and cohesive tungsten carbide coatings, some of the benefits that result from this process include:
- High Bond Strength
- Low Residual Stress
- Low Porosity (Typically Less Than 0.5%)
- High Wear Resistance
- Good Corrosion Resistance
Coating properties such as hardness, wear resistance, and strength depend primarily on the grain size and volume fraction of the tungsten carbide particles used in the HVOF thermal spray process. Therefore, HVOF tungsten carbide coatings can be adapted to provide the specific properties needed for an application by controlling the grain size of the tungsten carbide particles and their volume relative to cobalt.
HVOF Tungsten Carbide Thermal Spray Equipment
At ASB Industries, tungsten carbide thermal spray coatings are the most frequently-applied wear resistant surface treatments. With an array of HVOF thermal spray equipment at our disposal, we can choose the best powdered feedstock for your application and ensure consistent production. Our HVOF thermal spray rooms are designed to accommodate a wide range of components, utilizing large turning capabilities and equipment ranging from robots and X-Y gun manipulators to overhead cranes. Specialty-built fixtures are used to handle repetitive production; complex masking fixtures protect uncoated areas.
HVOF Thermal Spray Process
Tungsten carbide coatings are achieved through the HVOF tungsten carbide thermal spray process. Within this process a fuel gas and oxygen are combusted in a high-pressure chamber reaching temperatures up to 5,600°F (3,093°C). The resulting hot, high-pressure gas is ejected through a small-diameter nozzle and accelerated down a long barrel at supersonic speeds. Tungsten carbide powder (or another powdered coating material, as your project requires) is injected into the nozzle, where the particles mix with the speeding gases, reaching velocities up to 3,000 feet per second.
HVOF Thermal Spray Coating Applications
Erosion, abrasion, and corrosion are factors that should be considered when choosing different chemistries and binder materials. Tungsten carbide thermal spray coatings are typically used for extreme wear conditions. For example:
- ASB Industries’ on-site and in-house thermal spray technology allows us to apply long lasting, grip-surface HVOF tungsten carbide coatings to roll surfaces used in different paper production processes. Using our flame spray equipment, we can adapt our carbide spraying parameters to best accommodate the quality and thickness of the paper being produced.
- In steel and metals production, HVOF tungsten carbide coatings and tungsten weld coatings are widely used from ore production through finished product. A multitude of accepted applications show dramatically reduced maintenance costs and improved production quality.
- In power generation where coal is the fuel source, components must be protected from extreme abrasion under demanding production seasonal schedules. ASB Industries has a wide variety of HVOF thermal spray coating solutions for mission-critical components.
- If your application requires a specific finish, ASB Industries can apply HVOF tungsten carbide coatings to varying surfaces finishes or Ra. From large to small components, we will most likely be able to finish your project with our diamond grinding and diamond super finishing equipment.
Contact ASB Industries Today
Our proven HVOF thermal spray technology enables us to custom-tailor our tungsten carbide coatings to meet your unique application and performance requirements. Submit your project to receive a custom price quote, or contact ASB Industries to discuss HVOF thermal spray coatings for your equipment.