Thermal Spray Coatings

Thermal spray coatings are most often used for corrosion or erosion/abrasion protection. We have seen them used in recovery boilers, digesters, and on Yankee dryers. The alloy composition of the layers required to make up the coating is proprietary and chosen for the intended service conditions. The method of thermal spray coating application can be by flame, plasma, or detonation gun, each with slightly different results. The physical properties of the finished coating are what engineers are most interested in. We recommend the type of coating depending on application.

In our laboratory, we test samples of applied coatings , surface hardness, Vickers microhardness of individual layers, porosity/permeability and alloy segregation. These properties will give us an idea of how the coating will perform in service. The results of this type of testing are generally qualitative and require some material engineering judgment to evaluate. Often we compare potential coating systems using these tests and report our results and recommendations to the client.