Gordon England Surface Engineering Forum

Metallography of Thermal Spray Coatings
Effects of Different Grinding and Polishing Preparation Techniques

Ceramic coating prepared using fairly typical metallographic techniques
for ferrous materials, showing the effects of particle pluck outCeramic coating prepared using fairly typical metallographic techniques
for ferrous materials, showing the effects of particle pluck outCeramic coating prepared using special metallographic techniques
for thermal spray coatings, showing improved results

Photomicrographs of the same poorly plasma sprayed alumina / 3% titania coating at about X50 magnifgication. This coating was poorly sprayed by depositing the coating too thickly per pass generating lamination faults. The metallographic preparation precedure for each was slightly different. The two photomicrographs on the left were prepared using fairly typical metallographic techniques for ferrous materials, showing the effects of "particle pluck out". The photomicrograph on the right was prepared using special developed techniques specifically for plasma sprayed alumina ceramic coatings, showing clearly the crack edges, unmelted particles and a more realistic view of density.

Ceramic coating prepared using fairly typical metallographic techniques
for ferrous materials, showing the effects of particle pluck outCeramic coating prepared using fairly typical metallographic techniques
for ferrous materials, showing the effects of particle pluck outCeramic coating prepared using special metallographic techniques
for thermal spray coatings, showing improved results

Photomicrographs of the same plasma sprayed alumina/3% titania coating at about X250 magnifgication.








Alternative Site Recommended for Users of Netscape Navigator and Browsers Not Displaying this Page Properly