Substitution of electroplated hard chromium, a process that uses hexavalent chromium, with HVOF tungsten carbide cobalt or cobalt-chrome coatings on hydraulic piston rods, landing gear, actuators and pump plungers. HVOF carbide is harder and more wear resistant than chrome, avoids plating-related hydrogen embrittlement and carries a smaller fatigue debit, but it needs diamond grinding and careful edge design.
Landing gear on this contract is all hard chrome replacement, HVOF WC-CoCr and superfinish.
Carbide does not like square edges or flexing; designs copied straight from a chrome drawing often chip at the shoulders.
Also heard as
- chrome replacement
- HCR
Related terms
HVOF
High-velocity oxygen fuel: burning fuel and oxygen under pressure to fire powder at supersonic speed.
WC-Co
Tungsten carbide in a cobalt binder, the most common wear-resistant thermal spray coating.
Carbide
Shop shorthand for a carbide coating, usually tungsten carbide, as in putting carbide on a part.
Grind stock
Extra coating thickness sprayed beyond the final size so it can be ground or machined to finish.