Protective coatings for aircraft engine components
An aircraft engine component ( 100 ) may include a wall ( 200 ) comprising an aluminum alloy and/or a magnesium alloy, and a protective coating ( 108 ) covering the wall ( 200 ). The protective coating ( 108 ) may include a prime layer ( 206 ), a silicone elastomer layer ( 208 ), and an abrasion resistant layer ( 210 ). The prime layer ( 206 ) may at least partially cover a surface ( 202 ) of the wall ( 200 ). The prime layer ( 206 ) may include a silane coupling agent and an organic titanate. The silicone elastomer layer ( 208 ) may at least partially cover the prime layer ( 206 ). The silicone elastomer layer ( 208 ) may include one or more filler materials dispersed in a matrix of cross-linked silicone polymers. The abrasion resistant layer ( 210 ) may at least partially cover the silicone elastomer layer ( 208 ). The abrasion resistant layer ( 210 ) may include a fiber-reinforced elastomeric material.
1. An aircraft engine component, comprising:
a wall comprising an aluminum alloy and/or a magnesium alloy; and
a protective coating at least partially covering a surface of the wall, the protective coating comprising:
a prime layer at least partially covering the surface of the wall, the prime layer comprising a silane coupling agent and an organic titanate;
a silicone elastomer layer at least partially covering the prime layer, the silicone elastomer layer comprising one or more filler materials dispersed in a matrix of cross-linked silicone polymers, wherein the silicone elastomer layer has a density of 0.2 g/cm 3 to 0.6 g/cm 3 and a Shore A hardness, when cured, of 30 to 80 according to ASTM D2240-15e1; and
an abrasion resistant layer at least partially covering the silicone elastomer layer, the abrasion resistant layer comprising a fiber-reinforced elastomeric material, wherein the abrasion resistant layer has a density of 0.9 g/cm 3 to about 1.4 g/cm 3 and a Shore A hardness, when cured, of 40 to 90 according to ASTM D2240-15e1.
2. The aircraft engine component of claim 1 , wherein the prime layer has a thickness of from 25 micrometers to 50 micrometers.
3. The aircraft engine component of claim 1 , wherein the silicone elastomer layer has a thickness of 1,000 micrometers to 10,000 micrometers.
4. The aircraft engine component of claim 1 , wherein the abrasion resistant layer has a thickness of from 150 micrometers to 500 micrometers.
5. The aircraft engine component of claim 1 , wherein the silicone elastomer layer comprises one or more filler materials that have an average a cross-sectional width of 10 nanometers to 1,000 micrometers.
6. The aircraft engine component of claim 1 , wherein the wall comprises a surface treatment, wherein the surface treatment comprising a chemical conversion coating or an anodizing coating.
7. The aircraft engine component of claim 1 , wherein the silane coupling agent comprises at least one of: a trialkoxysilane, a monoalkoxysilane, or a dipodal silane.
8. The aircraft engine component of claim 1 , wherein the organic titanate comprises at least one of: ethyl acetoacetate titanate, di-iso-butoxy titanium, di-n-butoxy titanium, di-iso-propoxy titanium, n-Butyl polytitanate, tetra n-Butyl titanate, titanium butoxide, titanium ethylacetoacetate, or titanium tetraisopropoxide.
9. The aircraft engine component of claim 1 , wherein the prime layer is applied using a solution that comprises: light aliphatic naphtha in an amount of 75 to 95 wt. %; tetrakis2-butoxyethyl orthosilicate in an amount of 4 to 6 wt. %; and tetra n-Butyl titanate in an amount of 4 to 6 wt. %.
10. The aircraft engine component of claim 1 , wherein the silicone elastomer layer comprises a silicone polymer derived from one or more polyorganosiloxanes.
11. The aircraft engine component of claim 1 , wherein the one or more filler materials comprises at least one of: glass microspheres, glass fibers, cenospheres, fumed silica, precipitated silica, silica fibers, silicon dioxide, silicon carbide, titanium dioxide, zinc oxide, rare earth minerals, silicate minerals, inosilicates, aluminum silicate, alumina trihydrate, polyepoxide microparticles, phenolic resin microspheres, ceramics, carbon fibers, carbon black, graphene, cellulosic fibers, or cork.
12. The aircraft engine component of claim 1 , wherein the silicone elastomer layer comprises a silanization agent.
13. The aircraft engine component of claim 12 , wherein the silanization agent comprises at least one of: an aminosilane, a glycidoxysilane, or a mercaptosilane.
14. The aircraft engine component of claim 1 , wherein the fiber-reinforced elastomeric material of the abrasion resistant layer comprises one or more silicone polymers and one or more fibrous reinforcing materials.
15. The aircraft engine component of claim 14 , wherein the one or more fibrous reinforcing materials have an average length of 1 micrometer to 10,000 micrometers.
16. The aircraft engine component of claim 14 , wherein the one or more fibrous reinforcing materials have an average cross-sectional width of 1 μm to 50 μm.
17. The aircraft engine component of claim 14 , wherein the one or more fibrous reinforcing materials comprises at least one of: glass fibers, basalt fibers, carbon fibers, ceramic fibers, aramid fibers, polycrystalline fibers, or polysiloxane fibers.
18. The aircraft engine component of claim 1 , wherein the fiber-reinforced elastomeric material of the abrasion resistant layer comprises at least one of: one or thermoplastic materials or one or thermosetting materials.