Dark surface after grinding of plasma tungsten carbide coating

[Lazha]

Hi,

I am doing cylindrical grinding on shaft, plasma coated with tungsten carbide cobalt powder (Metco72F-NS-1).
Sometimes the final product after grinding shows a dark surface instead of the usual bright and shiny surface. Does anyone have experience with this kind of occurrence in their grinding process?

Thanks

[loriolo]

Hi Lazha

I could not know identify your problem, because you don't told what system and gun did you used an parameters set, because spray of WcCo with plasma isn't too easy, it's better with HVOF, so I could suppose that the problem could be too much fines in the powder, powder feeding inadequate, with not correct spray geometry