PROTECTIVE COATING FOR INDUSTRIAL PARTS

1 . A protective coating for an industrial part working surface, the protective coating comprising:

a first protective portion including marker particles in a first coating matrix, the marker particles making up from about 5 to 40 volume percent of the first protective portion and each marker particle having an average diameter ranging from about 0.01 microns to 100 microns; and

at least one additional protective portion positioned on the first protective portion, the at least one additional protective portion including a second coating matrix, and either i) a decreased amount of marker particles in comparison to an amount of the marker particles in the first protective portion or ii) no marker particles in the second coating matrix.

2 . The protective coating of claim 1 wherein the first protective portion is a first layer of the coating, and wherein the at least one additional protective portion is a second layer of the coating that is separate from the first layer.

3 . The protective coating of claim 1 wherein the first protective portion and the at least one additional protective portion are part of a single composition in which the first and second coating matrices are the same and at least a majority of the marker particles settle into the first protective portion.

4 . The protective coating of claim 1 wherein the coating matrices are selected from the group consisting of fluorocarbon polymers, gold, gold alloys, aluminum, silicon, carbon fiber, carbon nanofibers, carbon filaments, carbon nanotubes, silicon dioxide, silicon-germanium, tungsten, silicon carbide, silicon nitride, silicon oxynitride, titanium nitride, zirconium oxide, aluminum bronze, calcium zirconate, pure aluminum, cobalt-molybdenum, chromium cobalt, aluminum oxide, tungsten carbide, copper-aluminum alloys, copper-nickel alloys, copper-tin alloys, copper-zinc alloys, chromium carbide, nickel graphite, 316 stainless steel, fused nickel chromium, high carbon-iron-molybdenum composite, fused nickel-cobalt, fused tungsten carbide, white aluminum oxide, zinc, copper, aluminum oxide-titanium nickel aluminide, molybdenum, fused nickel-cobalt, nickel chromium, chromium oxide, titanium dioxide, stainless steel, low carbon steel, phosphate conversion, tin alloys, vitreous enamels, nickel alloys, aluminum-titanium dioxide, and tungsten, and combinations thereof.

5 . The protective coating of claim 1 wherein the marker particles include either a) particulates which change color upon exposure to air, the particulates including metals selected from the group consisting of magnesium, copper, zinc, aluminum, silica, and combinations thereof, or b) encapsulated metal particles selected from the group consisting of carboxy-functionalized silver, carboxy-functionalized titanium dioxide, amine-functionalized gold, carboxy-functionalized cerium (IV) oxide, carboxy-functionalized Fe 2 O 3 , carboxy-functionalized CdS-capped CdTe, carboxy-functionalized palladium, carboxy-functionalized zinc oxide, and combinations thereof, or c) encapsulated solid dye particles selected from the group consisting of fluorescent colored particles, carboxyl colored particles, carboxyl fluorescent colored particles, carboxyl-polystyrene colored particles, dimethylamino fluorescent particles, fluorescent carboxyl colored particles, fluorescent carboxyl colored particles, fluorescent polymethylmethacrylate colored particles, colored polystyrene particles, and combinations thereof; or d) combinations of at least two of a), b), and c).

6 . The protective coating of claim 1 wherein a total thickness of the coating ranges from about 5 to 500 microns.

7 . The protective coating of claim 1 wherein the first protective portion includes from about 20 to 40 volume percent of the marker particles, wherein each of the marker particles has an average diameter ranging from about 0.01 to 1 micron; and wherein a total thickness of the coating ranges from about 5 to 50 microns.

8 . The protective coating of claim 1 wherein the at least one additional protective portion includes at least two additional protective portions, wherein a first of the at least two additional protective portions includes a concentration of marker particles less than a concentration in the first protective portion and a second of the at least two additional protective portions includes a concentration of marker particles less than the concentration in the first of the at least two additional protective portions, and wherein the protective coating thus includes a gradient of increasing concentration of marker particles in a direction toward the industrial part working surface.

9 . The protective coating of claim 1 wherein the first protective portion includes from 5 to 20 volume percent of the marker particles, wherein each of the marker particles has an average diameter ranging from about 1 to 100 microns, and wherein a total thickness of the coating ranges from about 50 to 500 microns.

10 . A method of making a protective coating on an industrial part working surface, the method comprising:

applying a first protective layer to the industrial part working surface, the first protective layer including:

a coating matrix; and

marker particles mixed in the coating matrix, the marker particles having an average diameter ranging from 0.01 microns to 100 microns, and being present in the coating matrix in an amount ranging from 5 to 40 volume percent of a total volume of the first protective layer; and

applying at least one additional protective layer on the first protective layer, the at least one additional protective layer including:

a same coating matrix as the coating matrix of the first protective layer; and

either i) a decreased amount of marker particles in comparison to an amount of the marker particles in the first protective layer or ii) no marker particles;

wherein the at least two protective layers are applied to the industrial part working surface by an applying method selected from the group consisting of electroless metal plating, physical vapor deposition, chemical vapor deposition, plasma spray, and combinations thereof.

11 . The method of claim 10 wherein the coating matrices are selected from the group consisting of fluorocarbon polymers, gold, gold alloys, aluminum, silicon, carbon fiber, carbon nanofibers, carbon filaments, carbon nanotubes, silicon dioxide, silicon-germanium, tungsten, silicon carbide, silicon nitride, silicon oxynitride, titanium nitride, zirconium oxide, aluminum bronze, calcium zirconate, pure aluminum, cobalt-molybdenum, chromium cobalt, aluminum oxide, tungsten carbide, copper-aluminum alloys, copper-nickel alloys, copper-tin alloys, copper-zinc alloys, chromium carbide, nickel graphite, 316 stainless steel, fused nickel chromium, high carbon-iron-molybdenum composite, fused nickel-cobalt, fused tungsten carbide, white aluminum oxide, zinc, copper, aluminum oxide-titanium nickel aluminide, molybdenum, fused nickel-cobalt, nickel chromium, chromium oxide, titanium dioxide, stainless steel, low carbon steel, oxide coatings on steel, phosphate conversion, tin alloys, vitreous enamels, nickel alloys, aluminum-titanium dioxide, and tungsten, and combinations thereof.

12 . The method of claim 10 wherein the marker particles include either a) particulates which change color upon exposure to air, the particulates including metals selected from the group consisting of magnesium, copper, zinc, aluminum, silica, and combinations thereof, or b) encapsulated metal particles selected from the group consisting of carboxy-functionalized silver; carboxy-functionalized titanium dioxide; amine-functionalized gold; carboxy-functionalized cerium (IV) oxide; carboxy-functionalized Fe 2 O 3 ; carboxy-functionalized CdS-capped CdTe; carboxy-functionalized palladium; carboxy-functionalized zinc oxide and combinations thereof, or c) encapsulated solid dye particles selected from the group consisting of fluorescent colored particles, carboxyl colored particles, carboxyl fluorescent colored particles, carboxyl-polystyrene colored particles, dimethylamino fluorescent particles, fluorescent carboxyl colored particles, fluorescent carboxyl colored particles, fluorescent polymethylmethacrylate colored particles, colored polystyrene particles, and combinations thereof, or d) combinations of at least two of a), b) and c).

13 . The method of claim 10 wherein the first protective layer and the at least one additional protective layer are applied with physical vapor deposition or chemical vapor deposition, wherein the marker particles make up from 20 to 40 volume percent of the first protective layer, wherein each of the marker particles has a diameter ranging from 0.01 to 1 micron, and wherein a total thickness of the coating ranges from 5 to 50 microns.

14 . The method of claim 10 wherein the first protective layer is applied with plasma spray, wherein the marker particles make up from 5 to 20 volume percent of the first protective layer, wherein each of the marker particles has a diameter ranging from 1 to 100 microns, and wherein a total thickness of the coating ranges from 50 to 500 microns.

15 . The method of claim 10 wherein the at least one additional protective layer includes at least two additional protective layers, and wherein the method further comprises:

applying a first of the at least two additional protective layers on the first protective layer, the first of the at least two additional protective layers including a concentration of marker particles that is less than a concentration in the first protective layer; and

applying a second of the at least two additional protective layers on the first of the at least two additional protective layers, the second of the at least two additional protective layers including a concentration of marker particles that is less than the concentration in the first of the at least two additional protective layers, thereby creating a gradient of increasing concentration of marker particles in a direction toward the industrial part working surface.

16 . A method of making a protective coating on an industrial part working surface, the method comprising:

preparing a composition of a coating matrix in a powder or liquid form with marker particles therein, the marker particles making up from 5 to 40 volume percent of the mixture, and having an average diameter ranging from 0.01 microns to 100 microns; and

applying the composition to the industrial part working surface, thereby forming the protective coating, whereby the marker particles sediment toward a first protective portion of the protective coating that is adjacent to the industrial part working surface, thus causing a second protective portion to form which includes either i) a decreased amount of marker particles in comparison to an amount of the marker particles in the first protective portion or ii) no marker particles;

wherein the protective coating is applied to the industrial part working surface via an applying method selected from the group consisting of electroless metal plating, plating physical vapor deposition, chemical vapor deposition, spraying, plasma spraying, burnishing, dipping and combinations thereof.

17 . The method of claim 16 wherein the coating matrix is selected from the group consisting of fluorocarbon polymers, gold, gold alloys, aluminum, silicon, carbon fiber, carbon nanofibers, carbon filaments, carbon nanotubes, silicon dioxide, silicon-germanium, tungsten, silicon carbide, silicon nitride, silicon oxynitride, titanium nitride, zirconium oxide, aluminum bronze, calcium zirconate, pure aluminum, cobalt-molybdenum, chromium cobalt, aluminum oxide, tungsten carbide, copper-aluminum alloys, copper-nickel alloys, copper-tin alloys, copper-zinc alloys, chromium carbide, nickel graphite, 316 stainless steel, fused nickel chromium, high carbon-iron-molybdenum composites, fused nickel-cobalt, fused tungsten carbide, white aluminum oxide, zinc, copper, aluminum oxide-titanium nickel aluminide, molybdenum, fused nickel-cobalt, nickel chromium, chromium oxide, titanium dioxide, stainless steel, low carbon steel, oxide coatings on steel, phosphate conversion, tin alloys, vitreous enamels, nickel alloys, aluminum-titanium dioxide, and tungsten, and combinations thereof.

18 . The method of claim 16 wherein the marker particles include either a) particulates which change color upon exposure to air, the particulates including metals selected from the group consisting of magnesium, copper, zinc, aluminum, silica, and combinations thereof; or b) encapsulated metal particles selected from the group consisting of carboxy-functionalized silver; carboxy-functionalized titanium dioxide; amine-functionalized gold; carboxy-functionalized cerium (IV) oxide; carboxy-functionalized Fe 2 O 3 ; carboxy-functionalized CdS-capped CdTe; carboxy-functionalized palladium; carboxy-functionalized zinc oxide and combinations thereof; or c) encapsulated solid dye particles selected from the group consisting of fluorescent colored particles, carboxyl colored particles, carboxyl fluorescent colored particles, carboxyl-polystyrene colored particles, dimethylamino fluorescent particles, fluorescent carboxyl colored particles, fluorescent carboxyl colored particles, fluorescent polymethylmethacrylate colored particles, colored polystyrene particles, and combinations thereof, or d) combinations of at least two of a), b) and c).

19 . The method of claim 16 wherein the composition is applied with physical vapor deposition or chemical vapor deposition, wherein the marker particles make up from 20 to 40 volume percent of the first protective portion, wherein each of the marker particles has a diameter ranging from 0.01 to 1 micron, and wherein a total thickness of the coating ranges from 5 to 50 microns.

20 . The method of claim 16 wherein the composition is applied with plasma spray, wherein the marker particles make up from 5 to 20 volume percent of the first protective portion, wherein each of the marker particles has a diameter ranging from 1 to 100 microns, and wherein a total thickness of the coating ranges from 50 to 500 microns.

21 . The method of claim 16 wherein the marker particles sediment to form throughout the coating matrix a gradient of increasing concentration of marker particles in a direction toward the industrial part working surface.