HVAF Flash Carbide As Economical Alternative To Electroplated Hard Chrome

Applications of thermal spray (TS) coatings for replacement of electroplated hard chrome (EHC) are limited due to the high cost of existing TS coatings. This cost is associated with the need to spray relatively thick layers followed by grinding to specified dimensions. A substantial part of applied coating is removed during grinding. The developed HVAF “Flash Carbide” process deposits very fine powders of WC-10Co-4Cr, creating dense layers at thickness as low as 25-40 micron and with surface roughness Ra 1.5-1.6 micron. Such thickness is comparable with the common tolerances on rods and shafts, while as-sprayed coating roughness is similar to typical ground surface. As a result, the dimensional grinding is not needed. Subsequent polishing removes only 5-9 micron to reach Ra 0.1-0.2 micron – sufficient for majority of industrial applications using EHC. Superior properties and low cost of the HVAF “Flash Carbide” makes it an attractive economical alternative to EHC.