Delamination

[bgmach]

Hey All...

I am spraying an inside diameter of a 7.5" outside diameter seal with a thin wall 0.060" with metco 444 and am having problems with adhesion. Im confident with our powder feed rates, gases and preparation. What im not sure about is the proper RPM of the substrate and temperature control. We are also spraying into a shoulder so turbulance could be an issue.
Any suggestions?

New here so if there is further information needed please let me know.

[Gordon]

Hi bgmach

to the Surface Engineering Forum.

What is the equipment/process that you are using and the thickness of coating?

Improving ventilation/air flow around the spray area to remove dust and debris. Try not to use shorter spray distance/stand off than recommended and if anything use lower than recommended powder feed rates, particularly if you are using the high spray rate parameters. Usually, Metco 444 is a pretty tolerant with good thickness limitation/low stress and normally doesn't mind getting a bit hot (certainly more so than other coatings ).

[Vijay Deshpande]

Dear Bgmach,
I have also observed this phenomena while coating on ID. This may be due to compressive stress build up which manifests in lamination problem. May be u have to control inerpass temperature.
Vijay Deshpande