HVOF Determining Coat Thickness

[Josgates]

Hi Members,

I just have a query regarding HVOF coating thickness.
Say I wanted to coat a paper machine roller for corrosion, abrasion, and wear resistance. I'd want to use something like 86WC/10Co/4Cr to meet these characteristics. My question is how does one determine the thickness of coating to apply, and the spray distance (these will be related)? From my understanding too thick a coating can cause problems with a potential temperature differential and cracking and too thin a coating may not provide the needed protection.

I understand each system will have different parameters you can control to influence such outputs (like the fuel ratios) but my question is more about how do you know how thick a coating to apply? Are there industry standards for such things or does it mainly come from experience?

I'm rather new to the world of HVOF / HVAF but have been looking into it's usefulness so any information or useful readings that could help me would be much appreciated. Thanks.

[Met.Eng.]

Yes there are some thcks limitation.
I tell u ony for gas fuel hvof like dj propane.
Optimum thicknesses
CrC nicr 400 mic
Wc co , wc co cr 200 mic
And also coarse powders has much thicker than fine ones