Liquid coatings

Liquid coatings usually start as a liquid or slurry and can be applied by air spray, dip spin, or hand brushed.  The application of the coating is followed by a thermal cure. Typical coatings include;

Corrosion Coatings

This technology is used in the gas turbine industry to coat compressor components,  such as blades, vanes, blisks, and rotors. Typically used as a sacrificial or corrosion inhibiting layer for atmospheric protection, this process applies a paint-like, thermally cured coating. This process is typically designed for the low temperature, compressor side of the turbine engine, and can be sprayed to very smooth surface finishes of less than 20aa with no further finishing required. Typically, metallic and ceramic based slurries are used for these applications. They can be a single layer or bi-layer with both a sacrificial and sealing layers.

Dri-Film Lube

Dri-Film Graphite or Moly Disulfide Lube and PTFE coatings are used to provide lubricating properties to a wide variety of components.  This can aid installation or provide lubrication when oils and grease are not practical.   Coated components can be metals for engine or structural components or elastomers, such as O-rings.  Temperature limitations are typically 650’F or less depending on specific coating and substrate limitations.

Advantages

• Flexible methods of application.
• Relatively thin, range from approximately .0005 degrees – .0035 degrees.
• Allows for lower cost substrate material to be utilized and still provide corrosion resistance.
• Reduces the risk of damage during installation.
• Can be stripped easily and reapplied during overhaul and repair cycles.

Applications

• Gas turbine compressor blades, vanes, blisks, and rotors
• Automotive o-rings and engine components
• Aircraft structural components

Process Details

Process can be very sophisticated where components are robotically air sprayed in humidity and temperature-controlled atmospheres or very simple where less stringent components are hand brushed.  In the cases of high-volume automotive products, various spray tumbling and dip spin techniques can be utilized to drive very high throughputs.   The vast majority of the coatings require a thermal cure as part of the application.