Metallography Evaluation

[vcduramais]

Dear all,

hope you are doing fine.

I made asked a new company (due to covid-19 the one I used to do is not opperating) for a metallografy analisys of my WC 10Ni (-45/+15) coating sprayed with HVOF air cooled (GTV 720.000 - propylene). I'm having porosity problem resulting in cylinder rods "undermining oil" when they leave the cylinder. I'm doing this test so I can find the problem and to compare the coating from this equipment with the one I'm going to do with the new equipment our company is acquiring (MEC 2700).

I'm ataching the microphtografy so you can se what is going one. I can't tell if there was a poor preparation or if this is actually what is going on.

If our coating is this poor, can you please tell me if it could be due to compressed air contaminated with oil?

Thank you and best regards