Surface Quality
The bond strength of a coating is critical for thermal spray applications. The bond strength is dependent on the type of coating material, substrate surface preparation and spray parameters.
While spray parameters are optimized carefully, most surface preparation is done by manual grit blasting, with little or no calibration of blast parameters and unpredictable operation cycle time and quality. Blasting is highly dependent on operator skill and often surface finish is only assessed visually, which means that a consistent, reproducible surface profile cannot be guaranteed. Moving a workpiece from a blasting room to the spray shop carries the risk of oxidation or contamination of the blasted surface.
HVAF hot grit blasting, in contrast, is fully automated and provides predictable, high-quality results.
The thermal spray coating is executed immediately after blasting, which minimizes the risk of oxidation.
