APPARATUS AND PROCESS FOR PRODUCING COATINGS

Abstract

An apparatus is disclosed for applying a coating to a desired object including a rotatable container having at least one container wall. An electrolyte can be retained within the container, the at least one container wall made of a material that does not allow the electrolyte to pass through the at least one container wall of the container. An anode can be positioned within the container. The apparatus can include a mount for securing the desired object such that a surface of the desired object is exposed to the electrolyte. A controller can be in electrical communication with the anode and the mount, wherein when power is supplied from the controller to the anode and the mount, particles in the electrolyte are deposited on the desired object forming a composite coating.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/921,968 filed Jul. 18, 2019 entitled APPARATUS USED FOR PRODUCING COATINGS, which is hereby incorporated by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The subject matter herein was funded in part by Department of Energy Grant DE-FC26-FE0007332 and the Office of Naval Research Grant N00014-14-1-0341.

A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

REFERENCE TO SEQUENCE LISTING OR COMPUTER PROGRAM LISTING APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus and method for electrodepositing composite coatings in which a matrix containing embedded particles is produced through codeposition of insoluble particles suspended in a plating solution.

Electrodeposition of a metallic coating on the surface of an article is well known, as disclosed in U.S. Pat. Nos. 2,425,359; 2,447,270; and 2,706,175, all of which are incorporated herein by specific reference for all purposes. U.S. Pat. No. 4,305,792, also incorporated herein by specific reference for all purposes, discloses a hollow container for the electrodeposition of composite coatings, consisting of a metal matrix and embedded particles. Part of the container wall is impervious to the particles but pervious to the plating solution. The container is immersed in a plating tank containing the electrolyte. The pervious wall of the container is made of two outer layers of porous neoprene and an inner layer of filter paper. The neoprene layers, which are 3 millimeters thick, exhibits a nominal pore size of 10 micrometers while the filter paper has a nominal pore size of 2 micrometers. During electrodeposition, the article that was placed inside the container was rotating with the container along a horizontal axis or an axis that was slightly inclined to the horizontal.

A major disadvantage of prior art devices is that the particles placed inside the container need to be large enough to stay in the container. Particles smaller than the pore size of the pervious wall would either escape from the container or be trapped in the wall. Prior art devices therefore are not suitable for electrodeposition of composite coatings containing small particles, particularly for submicron particles or nanoparticles. In addition, the prior art devices cannot be used to apply composite coatings to internal surfaces of hollow articles.

BRIEF SUMMARY

This Brief Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

One aspect of the present invention is an apparatus for applying a coating to a desired object. The apparatus can include a rotatable container having at least one container wall. An electrolyte can be retained within the container, the at least one container wall made of a material that does not allow the electrolyte to pass through the at least one container wall of the container. An anode can be positioned within the container. The apparatus can include a mount for securing the desired object such that a surface of the desired object is exposed to the electrolyte. A controller can be in electrical communication with the anode and the mount, wherein when power is supplied from the controller to the anode and the mount, particles in the electrolyte are deposited on the desired object forming a composite coating.

Another aspect of the present disclosure is an apparatus for applying a coating to a desired object including a frame and a container rotatably disposed on the frame, the container having at least one container wall. A motor can be connected to the frame and coupled to the container, the motor selectively operable to rotate the container. A plating solution can be retained within the container, the plating solution containing submicron sized particles for coating the desired object, the at least one container wall made of a material that does not allow the plating solution or the particles contained therein to pass through the at least one container wall of the container. A mount can be provided for securing the desired object such that a surface of the desired object is exposed to the plating solution. When the desired object is secured, connected, mounted, or attached to the mount and the container is rotated via the motor, particles from the plating solution are deposited on the desired object as a coating.

Another aspect of the present disclosure is an apparatus for applying a coating to an object, the apparatus including a frame and a hollow desired object rotatably disposed on the frame, the desired object having at least one wall. A motor can be connected to the frame and coupled to the desired object, the motor selectively operable to rotate the desired object. An electrolyte can be retained within the desired object, the at least one wall of the desired object made of a material that does not allow the electrolyte to pass through the at least one wall of the desired object. As such, the desired object can be the container for retaining the electrolyte. An anode can be positioned within the desired object and the electrolyte. A controller can be in electrical communication with the anode and the desired object. Wherein when power is supplied from the controller to the anode and the desired object, particles in the electrolyte are deposited on the desired object forming a composite coating.

In various embodiments, the present invention can include an apparatus and related process for producing electrodeposited composite coatings, in which a metal matrix containing embedded particles is produced through codeposition of insoluble articles suspended in a plating solution. The particles can be ceramic, metallic, polymeric, or a combination of the three. Advantages for these coatings can include corrosion and oxidation resistance, wear resistance, and lubrication. The present apparatus can also be used in electroless plating processes. The composite coatings produced can be used as-deposited, or a post-deposition procedure such as a heat treatment can be performed to obtain the desired coating.

The present invention thus helps extend the capability of electrodepositing composite coatings containing particles smaller than the pore size of the prior art pervious wall containers and can be used to coat objects with particles in the submicron and nanometer range. The present invention also has the capability of producing composite coatings on internal surfaces of hollow articles.

Numerous other objects, advantages and features of the present disclosure will be readily apparent to those of skill in the art upon a review of the following drawings and description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the overall view of an apparatus for production of electrodeposited composite coatings.

FIG. 2 is a side view of the apparatus shown in FIG. 1.

FIG. 3 is a side elevation cross sectional view of the container assembly of the apparatus of FIG. 1.

FIG. 4 is a side elevation of another embodiment of an apparatus of the present disclosure wherein the container is the desired object and the inner surface of the container is to be coated.

FIG. 5 is an example of the composite coating plated in the apparatus.

FIG. 6 is a schematic view of an embodiment of an apparatus of the present disclosure for coating a desired object.

DETAILED DESCRIPTION

While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that are embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. Those of ordinary skill in the art will recognize numerous equivalents to the specific apparatus and methods described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.

In the drawings, not all reference numbers are included in each drawing, for the sake of clarity. In addition, positional terms such as “upper,” “lower,” “side,” “top,” “bottom,” etc. refer to the apparatus when in the orientation shown in the drawing. A person of skill in the art will recognize that the apparatus can assume different orientations when in use.

One aspect of the present invention, as shown in FIGS. 1-7, is an apparatus 100 for applying a coating to a desired object 14. The apparatus 100 can include a rotatable container 7 having at least one container wall 7a. An electrolyte 11 can be retained within the container 7, the at least one container wall 7a made of a material that does not allow the electrolyte 11 to pass through the at least one container wall 7a of the container 7. An anode 15 can be positioned within the container 7. The apparatus 100 can include a mount 18 for securing the desired object 14 or article to be coated such that a surface 14a of the desired object 14 is exposed to the electrolyte 11. The desired object can be mounted, attached to, connected to, or otherwise disposed on or secured to the mount using any suitable mechanism, including but limited to threads, clips, clamps, magnetic forces, etc. A controller 22 can be in electrical communication with the anode 15 and the mount 18, such that the desired object 14 or article is in electrical communication with the controller 22 via the mount 18, wherein when power is supplied from the controller 22 to the anode 15 and the mount 18, particles 20 in the electrolyte 11 are deposited on the desired object 14 as a composite coating.

The container 7 and the container walls 7a can be made of any suitable material that will not allow a plating solution or any particles containing therein to pass through the container walls 7a, or is otherwise impervious to the plating solution or any particles therein. The container wall 7a materials may be selected from a variety of materials, including for example materials such as polypropylene and polyethylene. In other embodiments, the container wall 7a material may be corrosion resistant and should not react with the electrolyte 11. In other embodiments, the container wall 7a materials can include, but are not limited to, metals, plastics, polymers, rubbers, etc. In some embodiments, the materials utilized for the container walls 7a can be rigid materials that can withstand and maintain their shape as the plating solution or electrolyte 11 move within the container as the container rotates.

In some embodiments, the apparatus 100 can include a frame 1, and a motor 2 can be mounted to the frame 1 and coupled to the container 7, the motor 2 selectively operable by the controller 22 to rotate the container 7. The controller 22 can control the motor 2 to rotate the container 7 at variable speeds as desired to facilitate particles 20 in the electrolyte 11 falling onto and coating various sides of the desired object 14 or article to be coated. In some embodiments, the container 7 can further include a cap 6. The motor 2 can be coupled to the cap 6 such that the container 7 is rotated by the motor 2 via the cap 6. In such embodiments, the mount 18 can be positioned on the cap 6 and/or integrated with the cap 6. As such, the container 7 and the mount 18 can be rotated via the cap 6 to rotate at the same rotational speed and both be driven by the motor 2. In other embodiments, the cap 6 and/or the mount 18 can be fixed such that the container 7 can rotate independently of the cap 2 and the mount 18, or the container 7 and the cap 2 and/or mount 18 can rotate at varying speeds.

In some embodiments, the apparatus 100 can further include a gear system 3 and 4 coupled between the motor 2 and the container 7 and/or the cap 6, wherein the container 7 is rotated by the motor 2 via the gear system 3 and 4. The gear assembly 3 and 4 in some embodiments can include a driving gear 3 mounted to the drive shaft of the motor 2 and a driven gear 4 that can be rotatably attached to the frame 1 using one or more pins 5. The cap 6 for the container 7 can be attached to the driven gear 4 using any suitable connection mechanism, including but not limited to screws, bolts, adhesives, etc. In some embodiments, the cap 6 can be designed to form a twist-lock or threaded engagement with the container 7. This connection allows the electric motor 2 to rotate the container 7 via the gear assembly 3 and 4 and the cap 6. In other embodiments, the container 7 can be directly coupled to the driven gear 4. In some embodiments, the cap 6 can include a plug 9 that can be used to seal the container 7 during electrodeposition by using the cap 6 to compress an O-ring positioned on an underside of the plug 9 between the container 7 and the plug 9.

In some embodiments, as shown in FIG. 3, the container 7 can have a central axis of rotation 24. The mount 18 can be located along the central axis 24 of the container 7. As such, the desired object 14 when mounted on the mount 18 can be generally aligned along the central axis 24 of the container 7. The anode 15 in such embodiments can be a hollow member such as a hollow cylinder and can be positioned within the container 7 and at least partially about the desired object 14 when the desired object 14 is mounted to the mount 18. In some embodiments, a hollow cylindrical anode 15 can be placed on the container wall 7a surrounding the article 14. In some embodiments, the anode 15 can also have axis of rotation that is parallel with the central axis 24 of the container 7.

In some embodiments, a first electrically conductive wire 17 can be electrically connected between the mount 18 and the controller (not shown), and a second electrically conductive wire 16 can be connected between the controller and the anode 15. As power from a power source of the controller is supplied to the anode 15 and the desired object via the mount 18, the anode 15 can become positively charged and the desired object 14 can become negatively charged, or become a cathode.

The article 14 and anode 15 are shown in FIG. 3 mounted inside the container 7 and submerged in electrolyte 11. In other cases (e.g., to apply coatings on the internal surface of a hollow article or an article with an internal cavity), the article acts as the container and the anode can be placed along the container axis with the article surrounding the anode. A conductive, non-reactive wire 16 can be used to connect the anode 15 to a power source for electrolytic deposition. To connect the article 14 to the power source on the controller another conductive wire 17 can be used. The conductive wire 17 can be connected to a mount 18 that supplies an electrical connection to the article 14 while securing the article 14 within the container 7. In some embodiments, clip connectors can be used to connect the power source of the controller to the conductive wires and allow them to rotate. However, in other embodiments the connection between the power source and conductive wires can be made through one or more slip rings 13. The mount 18 can be coupled to the plug 9 making the article 14 rotate at the same speed as the container 7 or decoupled so that the article 14 can rotate at a different speed/direction than the container 7.

In some embodiments, the container 7 can further include a trunnion 8, the anode 15 in electrical communication with the trunnion 8. In some embodiments, the container 7 can be a hollow cylinder or a cylinder with an internal cavity that is open on one end 26, the open end connecting to the cap 6 and/or the mount 18, the container 7 having a trunnion 8 extending from an opposing closed end (see FIG. 3). A trunnion 8 can generally be defined as a structure which acts as a point of rotation of the container 7 opposite from the open end and the cap 6 and the mount 18. In some embodiments, the trunnion 8 can have a generally cylindrical shape. The apparatus 100 can further include a slip ring 13 disposed on the trunnion 8. The slip ring 13 can be electrically communicated with the controller. The slip ring 13 can be oriented to maintain electrical contact between the trunnion 8 and the slip ring 13 while the slip ring 13 remains stationary and the container 7 and trunnion 8 rotate, such that the trunnion 8 and thus the anode 15 are in electrical communication with the controller via the slip ring 13. In some embodiments, the trunnion 8 can be disposed within and be rotatable relative to the slip ring 13. The trunnion 8 can include a circumferential electrical contact plate disposed around a circumference of the trunnion 8, and the slip ring can include a mating electrical contact or electrical contact brush that can maintain contact with the circumferential electrical contact plate on the trunnion 8 as the trunnion 8 rotates. In other embodiments, the circumferential electrical contact plate can be positioned on the slip ring 13 and the trunnion 8 can include the mating electrical contact or electrical contract brush.

In some embodiments, the apparatus 100 can further include a heating element 10 positioned on the container 7, wherein the electrolyte 11 can be heated as the heating element heats the container 7. In some embodiments, the heating element 10 can be a heating tape mounted outside the container 7. Having the heating element outside 10 of the electrolyte can help prevent corrosion of the heating element 10. In other embodiments, the heating element 10 can be placed inside the container to heat the electrolyte 11 directly, or the heating element 10 can be embedded in the container walls 7a. The heating element 10 can be any suitable heating structure, including heating tape, resistance electrical wiring, etc. In some embodiments, the apparatus 100 can further include a temperature sensor 12 extending through the container 7 and into the electrolyte 11, the temperature sensor 12 operable to monitor a temperature of the electrolyte 11. In some embodiments, the temperature sensor 12 can be any suitable thermocouple.

As the container 7 rotates on the frame 1, the heating element 10 and the temperature sensor 12 will rotate with the container 7. However, it is necessary to maintain electrical contact between the heating element 10 and the controller as well as between the temperature sensor 12 and the controller so that power can continuously be supplied to both heating element 10 and the temperature sensor 12 along with the anode 15, the motor 2, and the desired object 14. In embodiments wherein the container 7 further includes a trunnion 8 and the apparatus 100 includes a slip ring 13 in electrical contact with the controller, the anode 15, the heating element 10, and the temperature sensor 12 can each be in electrical communication with the trunnion 8, and specifically an electrical contact or circumferential electrical contact plate on the trunnion 8. A schematic diagram of this arrangement is shown in FIG. 6. A slip ring 13 is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. In this case, the slip ring 13 allows for the heating element 10 and temperature sensor 12 to rotate freely on the container 7 while providing an electrical connection to the stationary controller 22. As such, as the container 7 and the trunnion 8 rotate during use of the apparatus 100, power from the controller 22 can be supplied to each of the anode 15, the heating element 10, and the temperature sensor 12 via the stationary slip ring 13 and the rotating trunnion 8, which remain in electrical contact with one another as the trunnion 8 rotates within or on the slip ring 13. As such, the anode 15, the heating element 10, and the temperature sensor 12 are in electrical communication with the controller 22 via the slip ring. The constant electrical contact between the controller 22 and the heating element 10 and the temperature sensor 12 via the slip ring 13 and the rotating trunnion 8 can allow the controller 22 to efficiently monitor and control the temperature of the electrolyte 11.

In some embodiments, the container 7 can be a hollow object or an object with an internal cavity and can be the desired object to be coated, and particularly an inner surface 14a of the container 7, as shown in FIG. 4. In such embodiments, the container 7 can be removably connectable to a mount 18 or cap 6 with an inner surface 14a of the container exposed to the electrolyte 11, and the anode 15 can be positioned within the container 7. The cap 6 or mount 18 can be in electrical communication with the controller, such that power can be supplied from the controller to the container 7 via the cap 6 and/or the mount 18. In some embodiments, both the container 7 and the cap 6 and/or mount 18 can be electrically conductive or have sufficient electrical contacts between the container 7 and the cap 6 and/or mount 18 so that electricity can pass from the cap 6 and/or mount 18 to the container 7 freely. In other embodiments, once the container 7 is connected to the cap 6 and or mount 18, wiring from the controller can be electrically communicated with the container 7 directly.

As power is supplied from the controller to the container 7 and the anode 15, positively charged particles 20 in the electrolyte 11 are deposited on the inner surface 14a of the container 7.

In the embodiment show in FIG. 4, the container 7 can have a first end 26 and a second end 28, the cap 6 and/or mount 18 being removably connected to the first end 26 of the container 7. The apparatus 100 can further include a trunnion 8 removably connected to the second end 28 of the container 7, the anode 15 in electrical communication with the trunnion 8. As such, the container 7 can be in the shape of a hollow tube or cylinder, and the cap 6 and trunnion 8 can be secured to either end of the container 7 such that the electrolyte 11 can be retained within the container 7, the trunnion 8, and the cap 6 or mount 18. A slip ring 13 can be disposed on the trunnion 8 as described herein and electrically communicated with the controller, the slip ring 13 oriented to maintain electrical contact between the trunnion 8 and the slip ring 13 while the slip ring 13 remains stationary and the container 7 and trunnion 8 rotate such that the trunnion 8 and thus the anode 15 are in electrical communication with the controller via the slip ring 13.

In the embodiments discussed herein, the particles 20 in the electrolyte can include micron-, submicron- and nano-sized particles, and the container wall 7a can be made of a material that does not allow the particles 20 to pass through the at least one container wall 7a. As such, nanoparticle coatings can be applied to desired objects 14 utilizing the apparatuses 100 described herein without loss of the nanoparticles through the container 7, which provides a significant benefit over prior art devices that included porous container walls that were submerged in an electrolyte bath or plating solution.

In some embodiments, the apparatus 100 can include one or more baffles 19 positioned within the container 7 and extending into the electrolyte 11. The baffles or paddles 19 can help agitate the electrolyte as the container 7 is rotated which can help disperse particles within the electrolyte 11 to help ensure particles are spread out across the intended coating surface 14a of a desired object 14.

In various embodiments, the present disclosure includes an apparatus 100 and related process for producing electrodeposited composite coatings, in which a metal matrix containing embedded particles 20 is produced through codeposition of insoluble particles suspended in a plating solution or electrolyte 11. The particles 20 can be ceramic, metallic, polymeric, or a combination of the three. Advantages for these coatings include corrosion and oxidation resistance, wear resistance, and lubrication. The apparatuses 100 of the present disclosure can also be used in electroless plating processes by applying a chemical catalyst to a plating solution to produce desired particles to be coated on a desired object. For the electroless process, the present invention can be used without an external power source. In this case, an appropriate electroless bath should be used. The composite coatings produced can be used as-deposited, or a post-deposition procedure such as a heat treatment can be performed to obtain the desired coating.

In several exemplary embodiments discussed above, the present invention comprises a hollow container or a container with an internal cavity (such as, but not limited to, a hollow cylinder or a cylinder with an internal cavity) with walls that are impervious to the electrolyte 11 or plating solution and the particles 20 therein. The hollow container 7 holds the article 14 to be coated, the particles 20, and the electrolyte 11, or is the article 14 to be coated and holds the particles 20, the electrolyte 11 and the anode 15. In some embodiments, the apparatus 100 rotates during the coating process via an electric motor 2 and a gear assembly 3 and 4.

The container 7 in the present invention can be a variety of hollow geometric shapes, such as, but not limited to, a hollow tube or cylinder, a sphere, a polygonal tube, or a shape conforming to the article. In some embodiments, the container 7 itself can act as the anode or cathode. As an example, to apply coatings on the internal surface of a hollow article, the article 14 is the container 7 itself and the anode can be placed inside the container 7. By eliminating the plating tank in which the apparatus was immersed (as used, for example, in the prior-art system described in U.S. Pat. No. 4,305,792), the present invention leads to a significant reduction in the amount of particles and electrolyte needed to produce composite coatings. This advantage becomes very attractive when high cost items such as electrolytes for noble metal plating or diamond particles are involved in the process, or very long internal surfaces are to be coated with composite coatings.

The behavior of the particles 20 inside the container 7 is such that the particles 20 will be recirculated to the top of the container 7 and fall slowly downward due to gravity once the said particles 20 reach a particular height. This allows for a gentle interaction between the article surface 14a and the particles 20, thus increasing the likelihood of the particles 20 being incorporated in the coating. This behavior also allows for the particles 20 to be suspended in the container 7 with minimal agitation of the electrolyte, thereby reducing the chance of particles 20 not being incorporated due to crossflow across the article surface. For cases that do exhibit downward flow of particles 20, gravitational forces help the particles to penetrate the boundary layer at the article surface 14a, thus increasing the incorporation of particles 20. However, due to the settling of particles 20 onto the article surface 14a the article 14 can be rotated to prevent the buildup of sediment that can block the electrodeposition of the metal matrix. In various embodiments of the present invention, the rotation of the article 14 can be either coupled to the container (i.e., forcing it to rotate at the same speed), or the article can rotate at a different speed or direction by use of its own driving mechanism.

For the electrolyte, the composition should be appropriate for the particular application in which the apparatus is used. For example, for an MCrAlY coating (where the M represents a mixture of nickel and cobalt), a nickel-cobalt Watts solution or a nickel-cobalt all chlorideplating bath can be used. Another example is in the case of electroless deposition of a nickel-phosphorous coating containing alumina particles, where an appropriate electroless bath should be used.

In several embodiments, the walls of the container are impervious to the electrolyte, so that both electrolyte and particles are contained within the container 7. Therefore, small particles down to the nanometer range can be codeposited in the composite coatings using the present apparatus. In the prior art, rotating containers have pervious walls, and particles must be large enough to remain within the container.

Additionally, for the present invention there is no need for a tank containing a large amount of electrolyte, which helps make the present apparatus more cost effective than prior art methods.

A further advantage of the present invention is that it helps enable deposition of composite coatings on internal surfaces, since the article itself can act as the container for the apparatus as well as the cathode, thereby leading to significant cost savings, particularly for extremely long articles such as a pipe. In special cases, the container 7 itself can also be the anode. Prior art devices did not have the capability of depositing composite coatings on internal surfaces of a hollow article.

Another advantage of the invention is that for applications that require the electrolyte to be at a controlled temperature, the heat source can be placed on the outside of the container, within the walls of the container, or inside the container. When the heat source is placed on the outside of the container (such as the heating tape in FIGS. 1 and 2) or embedded in the container walls, no protection of the heat source against corrosion from plating electrolytes is required, unlike the corrosion protection that is required in prior art systems. A thermocouple for controlling the temperature may be used inside the container, but can be mounted on the outside wall as well. For electrolytic deposition, an anode can be placed inside the container either on the wall or along the container's axis of rotation, depending on the article being coated.

The present apparatus can stand on a dry floor or a desktop. Additionally, a slip ring is used in the present invention to allow the heating system and thermostats to function on the rotating system.

Prior art systems typically use large tanks containing stationary heaters to heat a much larger volume of plating solution. The present invention makes it possible to deposit composite coatings containing small particles down to the nanometer range on external or internal surfaces of articles with substantially uniform particle incorporation in the coating, which has not been previously demonstrated.

The present invention may be used in a variety of industries, since both composite and nano-composite coatings can be produced using the present invention. In particular, the present invention may be particularly useful for low-cost processes to produce composite coatings with improved oxidation/corrosion resistance, or with better lubricative properties.

In the field of high-temperature oxidation coatings (such as coatings on hot-section gas turbine components), the present invention offers a low-cost alternative to more expensive deposition processes such as plasma spraying, sputtering, and electron-beam physical vapor deposition. In fields such as tribology where electrodeposited composite coatings are already common practice, the present invention allows for incorporation of smaller particles while also reducing the amount of electrolyte needed. In cases where composite coatings are needed on internal surfaces of hollow articles for improved corrosion resistance, wear resistance, or lubrication, this unique design is the first reported approach, which also significantly reduces the coating processing cost by eliminating the need of a large plating tank containing a large amount of electrolyte. The present invention may be used in industries seeking a low-cost process to produce coatings with improved oxidation/corrosion resistance or better tribological properties, including but not limited to the following four categories:

(1) Anti-corrosion coatings: anti-corrosion coatings for metallic objects are prevalent in nearly every U.S. industry sector, from infrastructure and transportation to production and manufacturing. Protective coatings are one of the most commonly used methods to prevent corrosion in industries such as the infrastructure and transportation, as well as the marine and container industries.

(2) High-temperature oxidation coatings: coatings to protect against high-temperature oxidation, such as thermal barrier coatings (TBCs), are being used in a variety of market segments, including diesel and gas engines, aerospace and land based turbine engines, and aerospace structure applications. One of applications of the present invention is to apply the metallic bond coat on gas turbine components with significant cost reduction compared to the prior art plasma spraying or electron-beam physical vapor deposition.

(3) Tribological coatings: The field of tribology, including friction, wear, and lubrication, is of enormous practical importance, because many mechanical and electromechanical systems rely on friction and wear properties. The apparatus in this invention has the capability of codepositing hard ceramic particles to strengthen metallic coatings and improve wear resistance codepositing solid lubricant particles such as polytetrafluoroethylene (PTFE) and graphite to produce self-lubricated composite coatings.

(4) Nanostructured coatings: Nanostructured coatings are likely to replace traditional coatings in the medium to long-term in end use segments such as anti-microbial, architectural, industrial manufacturing, marine, auto refinish, and transportation. The present invention makes electrodeposition of nanostructured coatings possible via utilization of an impervious rotating container.

Thus, it should be understood that the embodiments and examples described herein have been chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited for particular uses contemplated. Even though specific embodiments of this invention have been described, they are not to be taken as exhaustive. There are several variations that will be apparent to those skilled in the art.

Thus, although there have been described particular embodiments of the present invention of a new and useful APPARATUS AND PROCESS FOR PRODUCING COATINGS, it is not intended that such references be construed as limitations upon the scope of this invention.

Claims

1. An apparatus for applying a coating to a desired object comprising:

a rotatable container having at least one container wall;

an electrolyte retained within the container, the at least one container wall made of a material that does not allow the electrolyte to pass through the at least one container wall of the container;

an anode positioned within the container;

a mount for securing the desired object such that a surface of the desired object is exposed to the electrolyte; and

a controller in electrical communication with the anode and the mount;

wherein when the desired object is secured to the mount and power is supplied from the controller to the anode and the mount, particles in the electrolyte are deposited on the desired object forming a composite coating.

2. The apparatus of claim 1, wherein the apparatus further comprises:

a frame;

a motor mounted to the frame and coupled to the container, the motor selectively operable by the controller to rotate the container.

3. The apparatus of claim 2, wherein:

the container further comprises a cap;

the motor is coupled to the cap such that the container is rotated by the motor via the cap; and

the mount is positioned on the cap such that the container and the mount rotate at the same rotational speed.

4. The apparatus of claim 2, further comprising a gear system coupled between the motor and the container, wherein the container is rotated by the motor via the gear system.

5. The apparatus of claim 1, wherein:

the container has a central axis of rotation;

the mount is located along the central axis of the container; and

the anode is a hollow member positioned within the container and at least partially about the desired object when the desired object is mounted to the mount.

6. The apparatus of claim 1, further comprising:

a first electrically conductive wire electrically connected between the mount and the controller; and

a second electrically conductive wire connected between the controller and the anode.

7. The apparatus of claim 1, wherein:

the container further comprises a trunnion, the anode in electrical communication with the trunnion; and

the apparatus further comprises a slip ring disposed on the trunnion and electrically communicated with the controller, the slip ring oriented to maintain electrical contact between the trunnion and the slip ring while the slip ring remains stationary and the container and trunnion rotate such that the trunnion and thus the anode are in electrical communication with the controller via the slip ring.

8. The apparatus of claim 1, further comprising a heating element positioned on an exterior of the container, wherein the electrolyte is heated as the heating element heats the container.

9. The apparatus of claim 8, further comprising a temperature sensor extending through the container and into the electrolyte, the temperature sensor operable to monitor a temperature of the electrolyte.

10. The apparatus of claim 9, wherein:

the container further comprises a trunnion, the anode, the heating element, and the temperature sensor are in electrical communication with the trunnion; and

the apparatus further comprises a slip ring mounted on the trunnion and electrically communicated with the controller, the slip ring oriented to maintain electrical contact between the trunnion and the slip ring while the slip ring remains stationary and the container and trunnion rotate such that the trunnion, the anode, the heating element, and the temperature sensor are in electrical communication with the controller via the slip ring.

11. The apparatus of claim 1, wherein the container is a hollow object and is the desired object to be coated, the container being removably connectable to the mount with an inner surface of the container exposed to the electrolyte, and the anode is positioned within the container.

12. The apparatus of claim 11, wherein the container has a first end and a second end, the mount being removably connected to the first end of the container and the apparatus further comprises:

a trunnion removably connected to the second end of the container, the anode in electrical communication with the trunnion; and

a slip ring disposed on the trunnion and electrically communicated with the controller, the slip ring oriented to maintain electrical contact between the trunnion and the slip ring while the slip ring remains stationary and the container and trunnion rotate such that the trunnion and thus the anode are in electrical communication with the controller via the slip ring.

13. The apparatus of claim 1, wherein the particles in the electrolyte include micron-, submicron- or nano-sized particles, and the container wall does not allow the particles from the anode to pass through the at least one container wall.

14. The apparatus of claim 1, further comprising one or more baffles or paddles positioned within the container and extending into the electrolyte.

15. An apparatus for applying a coating to a desired object comprising:

a frame;

a container rotatably disposed on the frame, the container having at least one container wall;

a motor connected to the frame and coupled to the container, the motor selectively operable to rotate the container,

a plating solution retained within the container, the plating solution containing micron-, submicron- or nano-sized particles for coating the desired object, the at least one container wall made of a material that does not allow the plating solution or the particles contained therein to pass through the at least one container wall of the container;

a mount for securing the desired object such that a surface of the desired object is exposed to the plating solution; and

wherein when the desired object is connected to the mount and the container is rotated via the motor, particles from the plating solution are deposited on the desired object as a coating.

16. The apparatus of claim 15, further comprising:

the plating solution being an electrolyte;

an anode positioned in the container; and

a controller in electrical communication with the anode and the mount;

wherein when the controller provides power to the anode and the mount when the desired object is connected to the mount, the particles in the electrolyte are deposited on the desired object.

17. The apparatus of claim 16, wherein the anode is a hollow cylindrical member that is positioned to surround the desired object when the desired object is mounted to the mount.

18. An apparatus for applying a coating to an object, the apparatus comprising:

a frame;

a hollow desired object rotatably disposed on the frame, the desired object having at least one wall;

a motor connected to the frame and coupled to the desired object, the motor selectively operable to rotate the desired object,

an electrolyte retained within the desired object, the at least one wall of the desired object made of a material that does not allow the electrolyte to pass through the at least one wall of the desired object;

an anode positioned within the desired object and the electrolyte; and

a controller in electrical communication with the anode and the desired object;

wherein when power is supplied from the controller to the anode and the desired object, particles in the electrolyte are deposited on the desired object forming a composite coating.

19. The apparatus of claim 18, wherein the apparatus further comprises:

a cap rotatably connected to the frame, the desired object removably connectable to the cap;

a trunnion removably connected to the desired object opposite the mount, wherein the electrolyte is retained between the desired object, the cap, and the trunnion.