What is the strength of powder coatings
Powder Coatings generally have poor strength, ductility and impact properties. These properties tend to be dictated by the “weakest link in the chain” which in coatings tends to be the particle or grain boundaries and coating/substrate interface. Coatings are limited to the load they can carry, and thus require a substrate for support, even then, coatings are poor when point loaded.
Internal tensile coating stresses generally adversely effect properties. Effective bond strength is reduced and can be destroyed by increasing levels of internal stress. This in turn effects coating thickness limits. Coatings on external diameters can be built up to greater thickness than that on internal diameters.
Surface properties such as wear resistance are usually good, but the properties are more specific to the material or materials used in the coating. The properties of a substrate need only to be strength, ease of fabrication and economic (like mild steel). The coating supplies the specific surface properties desired. For example, materials used for applications of thermal barrier and abradable clearance control by nature have poor strength and thus benefit from being applied as a coating onto a substrate which supplies the strength.
Some Properties Thermally Sprayed Coatings can Provide:
- Tribological (wear, resistance).
- Corrosion resistance.
- Heat resistance.
- Thermal barrier.
- Electrical conductivity or resistivity
- Abradable or abrasive.
- Textured surfaces.
- Catalyst and prosthetic properties,
- Restoration of dimension.
- Copying of intricate surfaces.