Surface modification of ceramic thermal sprayed coatings by sealing

The properties of thermal sprayed coatings depend on their microstructure and behavior of each layer. Not all coatings are used in their as-sprayed condition. Many metallic and ceramic coatings often need post-treatment, e.g. sealing, to extend the protective properties and service life, particularly working in immersed or hard conditions.

In this work we investigate the opportunity of decreasing roughness and increasing of thermal protection of the parts made of aluminum alloys using complex coatings. These complex coatings consist of thermal barrier coating and different types of sealers.

Sealed coatings were studied by means of cross-section optical microscopy, SEM, EDS and were tested at high velocity burner rig facility. It was shown that sealing treatment allows to reduce the roughness and improve thermal protection of parts.