Diamond Tuff™ HVOF Coating

Superior Coating

Solid Particle Erosion (SPE) is the major cause of wear for steam turbine buckets and diaphragm airfoils. GE's Diamond Tuff™ coating can reduce the wear on these components by providing a protective barrier of chromium carbide. Applied by High Velocity Oxy-Fuel (HVOF) spraying, Diamond Tuff™ is harder and more wear-resistance than conventional coatings.

When compared to the EPRI SPE coating, testing revealed diamond tuff was at least 10 times more resistant to magnetite erosion and two times more resistant to iron chromite erosion.

Magnetite Erosion Tests 12 Cr Base Metal
Uncoated 3.75 mg/g
EPRI Coated 0.319 mg/g
GE HVOF 0.033 mg/g
-200 mesh magnetite; 1,000°F gas temperature, 1,000 fps gas velocity, 30° impingement angle


Diamond Tuff Advantages
  • Excellent SPE resistance
  • 100 times the erosion resistance of unprotected 12 Cr base metal
  • At least twice the bond strength of air plasma sprays
  • Greater foreign object resistance
  • Smoother finish for reduced related efficiency loss
  • Short cycle coating times
  • Extended maintenance intervals
Diamond Tuff coating can also be used in certain industrial applications. For example, the coating has been applied to steel expanding noses, which are used in seamless pipe extrusion, resulting in a 300 percent increase in the useful life of these parts, for corrosive and abrasive applications.

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