HVAF
HVAF (High Velocity Air Fuel) is HTS Coatings' premium thermal spray process, improving on HVOF to produce stronger, more uniform, and highly ductile coatings that resist wear, corrosion, and cavitation damage.
What is HVAF Spray?
HVAF is short for high velocity air fuel. It is closely related to HVOF spray but improves upon its methods. HVAF produces stronger, more uniform coatings. The flame temperature of HVAF is closer to the melting point of most coatings materials, eliminating breakdown due to particle overheating. This also means that HVAF produces the most uniform mechanical coating of the types available at HTS Coatings. All of these advantages make HVAF coatings the most abrasion, wear and corrosion resistant. This low spray temperature also makes HVAF the most ductile coating; aiding in cavitation damage protection.
How it works
HVAF coating technology is the combustion of propane in a compressed air stream. Like HVOF, this produces a uniform high velocity jet. HVAF differs by including a heat baffle to further stabilize the thermal spray mechanisms. Material is injected into the air-fuel stream and coating particles are propelled toward the part. HVAF offers faster coatings at a lower spray temperature while increasing wear and corrosion resistance.
Advantages
- Produces stronger, more uniform coatings than HVOF
- Flame temperature closer to the melting point of most coating materials, eliminating breakdown from particle overheating
- The most abrasion, wear and corrosion resistant coating available at HTS Coatings
- The most ductile coating, aiding cavitation damage protection
- The only coating capable of preventing cavitation damage
- Allows thicker coating build up without the worry of cracking
- As-sprayed roughness of approximately 40 Ra, polishable down to less than 1 Ra
- Offers inner diameter spraying
- Environmentally friendly alternative to hard chrome plating
- Faster coatings at a lower spray temperature
Common applications
- Pump impellers
- Pump housings
- Hydraulic rods
- High wear parts
- Parts that require smooth surfaces and tight tolerances
- Cavitation damage resistance
- Corrosion resistance
HVAF Spray Solutions
The ductility of HVAF coatings makes it the only coating capable of preventing cavitation damage. This also allows for thicker coating build up without the worry of cracking. HVAF has an as-sprayed roughness of approximately 40 Ra and can be polished down to less than 1 Ra. This system also offers inner diameter spraying. HVAF coatings can also be used as an environmentally friendly alternative to hard chrome plating. HVAF can be sprayed on most anything but has added benefits for pump impellers, pump housings and hydraulic rods.
Common Coating Solutions:
- Tungsten Carbide
- Chrome plating alternative
- Premium Coating
Common Coating Materials:
- Tungsten Carbide
- Chrome Carbide
- Stainless Steel
- Hastelloy
- Inconel
HVAF Spray Coating Properties
| Property | Specification |
|---|---|
| Operating Cost | Premium |
| Bond Mechanism | Mechanical (>12,000 psi) |
| Max Flame Temperature | 3,560 to 3,650° F |
| Particle Velocity | 3,300 ft/sec |
| Max Spray Rate | 73 lbs/hr |
| Coating Thickness Range | 0.002" to 0.050+" |
| Special Features | Capable of high corrosion and wear resistant coatings, no heat distortion, ductile coatings |
| Wear Resistance | Excellent |
| Corrosion Resistance | Excellent |
| Porosity | Very Low |
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