Protective barrier coatings

摘要

Exemplary embodiments of the invention provide barrier coated substrates and methods of coating a substrate with a barrier coating derived from sol gels. An example includes a barrier coated aerospace component that is subject to hot salt corrosion during use. The barrier coating is derived from oxidation of a coating composition that includes at least one sol gel. The barrier coating resists hot salt corrosion for an incubation period of such duration that an uncoated superalloy substrate under the same conditions would suffer corrosion to a depth of about 2.0 mils. Methods of applying the barrier coating include the steps of selecting a first liquid sol gel and wetting surfaces of the superalloy substrate with the selected first liquid sol gel. The wetted surfaces of the superalloy substrate are subjected to heat treatment. The heat treatment includes sintering of sol gel to oxide to produce a barrier coating.