Abstract: A structural component which consists of a fiber-reinforced, composite material is provided with a protective coating against erosion. The protective coating includes an adhesion-promoting, intermediate layer on the component, an electrically insulating baked, inorganic lacquer layer for protection against erosion and an electrically conducting covering layer, for protection against lightning strikes. The covering layer consists of a baked and compressed inorganic lacquer and the lacquer of the lacquer layer and of the covering layer is baked on the component below the temperature which causes damage to the structural component or below the softening or decomposition temperature of the component. The protective layer is advantageously used for the external components of propulsion units, such as housings, nose cones or fan blades.

Abstract: A structural component of titanium or titanium alloy is provided with a protective coating made substantially of an oxidation resistant and diffusion inhibiting base layer (2), an intermediate layer (3) forming a titanium fire inhibiting layer, and a cover layer (4) forming a passivating sealing layer. These layers are applied by various methods.

Abstract: A structural component of titanium or titanium alloy is provided with a protective coating made substantially of an oxidation resistant and diffusion inhibiting base layer (2), an intermediate layer (3) forming a titanium fire inhibiting layer, and a cover layer (4) forming a passivating sealing layer. These layers are applied by various methods.

Abstract: Synthetic material substrates are protected against erosion and corrosion by a lacquer type coating which is baked or bonded onto the substrate at relatively low temperatures below 200.degree. C. to protect the synthetic material substrate against damage. The coating is a dispersion of metal powder in an aqueous solution of about equal weight proportions of phosphorous acid and phosphoric acid with an optional weight proportion of not more than 5 percent of aluminum phosphate, and about 10 to 20 weight percent of chromic acid. The remainder is water.