Nov 28, 2015 Off Comments in Powder Coating by

Manufacturers in industries ranging from aerospace and oil and gas to automotive rely on thermal spray coatings during the production of many of their key products. Parts such as gas turbines and engine components must not only have the ability to survive challenging and corrosive environments—they need to be able to do so for extended periods of time. Thermal spray coatings help protect the components to ensure their optimal performance and longevity.

While there are many different types of thermal spray processes, they generally involve spraying molten (sometimes semi-molten) materials such as metals or ceramics onto a prepared surface. In addition to wear and corrosion resistance, thermal spray coatings that incorporate fused materials like white aluminum oxide can also improve surface properties such as thermal insulation. Fused ceramic powders also offer multiple benefits even before the thermal spray process begins.

Preparing the Surface

Prior to the thermal spray coating application, the surface of the component needs to be well prepared in order to ensure the coating’s effectiveness and efficiency. The objective of surface preparation is to facilitate the adhesion of the thermal spray coating to the substrate. The coating cannot adhere properly if the surface is not well prepared, and the result is often costly and time-consuming failure.

Abrasive blasting is a common method of surface preparation for coatings that require both an anchor pattern and a high degree of surface cleanliness. Surface preparation with abrasive blasting increases the roughness of the surfaces as well as the coating’s adhesion strength. Blast cleaning can also completely remove intact rust and mill scale and produce an even roughness with a controlled anchor pattern.

Materials like aluminum oxide are a very effective blast media; they create a rough surface profile that offers excellent coating adhesion and performance. Fused brown and white aluminum oxide are blast materials that exhibit superior abrasion properties, as well as high corrosion and chemical resistance. Aluminum oxide is typically available in macro grit sizes ranging from 12 to 240 grit, and it is also low in iron so it leaves behind no impingements that can leave rust on the surface and cause potential problems in the future.

Read more: Cleveland Ohio Powder Coating: Optimizing Thermal Spray Coatings with Fused Ceramic Powders