System and method for localized electroless nickel plating - Patents.com

Abstract

A system (100) for electroless nickel plating a portion of a metal component (1000) comprises a chamber (10) that is fixedly coupled to the metal component (1000) during operation of the system (100), such that the portion of the metal component (1000) and the chamber (10) define an enclosed volume (V). The chamber (10) has an inlet (11) for providing at least a plating fluid (52) into the volume (V) and an outlet (12) for discharging the plating fluid (52) from the volume (V), such that the portion of the metal component (1000) is exposed to the plating fluid (52) and plated.

Description

[Technical field]

[0001] The subject matter disclosed herein relates to systems and methods for localized electroless nickel plating. [Background technology]

[0002] Typically, to provide and / or improve the corrosion resistance of metal parts used as machine components, the metal parts are subjected to a nickel plating process. In general, a nickel plating process is a process that deposits a layer of nickel on a metal part.

[0003] The process may use electroplating techniques or may be electroless. Typically, with nickel electroplating, a metal part is used as the cathode and is immersed in an electrolyte solution in which a nickel anode is immersed. When electricity flows, the nickel anode forms nickel ions, which migrate from the anode through the electrolyte solution and are deposited on the cathode, i.e., on the metal part. Electroless nickel plating, on the other hand, does not involve the use of electricity, the metal part is immersed in a plating bath, and the deposition of nickel occurs through a chemical reaction. Summary of the Invention [Problem to be solved by the invention]

[0004] However, repairing the coating of some metal parts by immersing the part in a liquid bath is particularly difficult. For example, the damaged or worn part may be a small part of the whole part, and therefore it is not easy or advantageous to immerse the part in the liquid bath. In some cases, even if it is not possible to disassemble the damaged part of the metal part, for example an impeller blade, the whole part must be removed from the machine, disassembled, and immersed.

[0005] It would be desirable to be able to locally repair the surface coating of a metal component without subjecting the entire metal component to a nickel plating process, and in particular, to locally repair the metal component without removing or disassembling the metal component.

[0006] According to one aspect, the subject matter disclosed herein relates to a system for electroless nickel plating of a portion of a metal component, wherein a chamber is configured to be fixedly coupled to the metal component such that the portion of the metal component and the chamber define an enclosed volume, and to receive, supply, and discharge at least a plating fluid such that plating occurs.

[0007] In accordance with another aspect, the subject matter disclosed herein relates to a method for localized electroless nickel plating of a portion of a metal component, the method comprising: - covering a portion of the metal part with a chamber so as to define an enclosed volume; - bonding the chamber to a metal part; - supplying a plating fluid into the volume through an inlet of the chamber; - discharging the plating fluid from the volume through an outlet of the chamber; - removing the chamber from the metal part. [Brief description of the drawings]

[0008] A complete understanding of the disclosed embodiments of the present invention and many of the attendant advantages thereof will be readily obtained as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which: [Figure 1] FIG. 1 shows a simplified diagram of one embodiment of a system for localized electroless nickel plating. [Diagram 2] FIG. 2 shows a partial simplified diagram of one embodiment of a system for performing localized electroless nickel plating. [Diagram 3]FIG. 3 shows a block diagram of one embodiment of a method for localized electroless nickel plating. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] According to one aspect, the subject matter disclosed herein relates to a system for locally depositing a layer of nickel plating on a portion of a metal part without the use of electricity. The portion of the metal part is intended to be a surface portion of the entire metal part. In fact, the chamber does not surround the entire part or the entire surface of the part. The system has a chamber, for example in the form of a jar or bowl or shell or cylindrical can or sheet, or in the form of another container, with an inlet and an outlet that can be secured to the metal part, for example with an adhesive or a magnet or a weight. When the chamber is secured to the metal part, the chamber forms an enclosed volume that can contain and supply, advantageously in a continuous manner, one or more fluids that are supplied to the volume through the inlet of the chamber and discharged from the volume through the outlet of the chamber. The chamber walls can have a constant or variable thickness, and the height of the chamber can vary from different points or segments relative to the metal part. At least a first fluid that is supplied to the volume is a plating fluid that reacts with a portion (or surface portion) of the metal part below the chamber and locally forms a deposit layer of nickel, i.e., a nickel plating. In at least one embodiment, the metal part and / or the chamber and / or the plating fluid are heated to at least 80°C, preferably to between 85°C and 95°C, and more preferably to between 88°C and 92°C.

[0010] According to another aspect, the subject matter disclosed herein relates to a method for locally depositing a layer of nickel (without the use of electricity) on a part of a metal component by passing a plating fluid over said part, i.e. locally forming a nickel plating. Preferably, the system described above can be used for this operation. Advantageously, during the operation, the metal component and / or the chamber of the system and / or the plating fluid are heated to at least 80°C, preferably to between 85°C and 95°C, more preferably to between 88°C and 92°C.

[0011] Next, the embodiments of the present disclosure will be described in detail, and examples thereof will be illustrated in the drawings. Each example and drawing is provided for the purpose of explaining the present disclosure, and should not be construed as a limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the scope or spirit of the present disclosure. In the following description, similar reference numbers are used in the description of the figures of the embodiment to indicate elements that perform the same or similar functions. Moreover, for clarity of illustration, some reference numbers may not be repeated in all figures.

[0012] In Fig. 1, a diagram of one embodiment of a system for performing localized electroless nickel plating is shown, generally designated by reference numeral 100, comprising a chamber 10, e.g., a rigid chamber 10. However, it should be noted that the chamber may also be a flexible chamber 20, e.g., as shown in Fig. 2. In Fig. 2, the system for performing localized electroless nickel plating is generally designated by reference numeral 200, comprising a flexible chamber 20. As will become apparent below, the systems 100 and 200 are configured to be coupled to a portion of a metal part 1000 for performing nickel plating deposition on a portion of its surface.

[0013] 1, the system 100 comprises a chamber 10 having an inlet 11 and an outlet 12, the chamber 10 configured to be fixedly coupled to a portion of the metal component 1000, in particular an underlying portion of the chamber 10, such that the chamber 10 and the chamber 10 define a closed volume V. The volume V of the chamber 10 may be configured to contain at least a first fluid, and in some embodiments, different fluids that are sequentially supplied to the chamber 10.

[0014] The inlet 11 is configured to supply a first fluid to the volume V and the outlet 12 is configured to discharge the first fluid from the volume V. Advantageously, the inlet 11 is located in a lower part of the chamber 10 (relative to the surface of the portion of the metal part when the chamber is in an operational state) and the outlet 12 is located in an upper part of the chamber 10 (relative to the surface of the portion of the metal part when the chamber is in an operational state). As will become clear below, the type and amount of fluid supplied to the volume V may vary, but the volume V is at least supplied with a plating fluid 52. In particular, known plating fluids already used in plating baths may be used to deposit a layer of nickel plating on the portion of the metal part 1000 below the chamber 10. Advantageously, the plating fluid 52 contains nickel and phosphorus, such that the plating fluid 52 may produce an alloy of phosphorus in the range of 10-13% by weight relative to nickel. For example, the plating fluid 52 may contain 21 g / L nickel sulfate and 24 g / L sodium hypophosphite. Advantageously, the plating fluid 52 is an acidic solution having a pH in the range of 4.3 to 4.6.

[0015] It is noted that a chemical reaction takes place in the volume V when the plating fluid 52 is in contact with the portion of the metal component 1000 below the chamber. In particular, as the chemical reaction takes place, gas bubbles are released inside the plating fluid 52. Advantageously, at least a portion of the chamber 10 can be made of a transparent or translucent material, so that an operator can check (in particular visually monitor) the progress of the reaction, for example by controlling the release of gas bubbles in the plating fluid 52.

[0016] As shown in FIG. 1, the chamber 10 may be rigid, particularly in the form of a bowl or jar. It is noted that for the purposes of the present invention, the term "rigid" is used to refer to a chamber that cannot be bent or forced out of shape. For example, at least a portion of the chamber 10 may be made of glass or metal or metal alloy. It is noted that in some embodiments, a portion of the chamber 10 may be the metal part itself. For example, if the part to be electroless nickel plated is the interior surface of a duct, the duct itself may function as the chamber by closing off the ends of the duct and providing an inlet at a first end and an outlet at a second end. With non-limiting reference to FIG. 1, the inlet 11 and outlet 12 are located on the sidewall of the chamber 10, specifically small holes that can accommodate a duct, which is preferably sealed at the inlet 11 and outlet 12.

[0017] As indicated above, the chamber 20 may be flexible, specifically in the form of a sheet or shell placed over a portion of the metal part 1000, as shown in FIG. 2. It is noted that for the purposes of the present invention, the term "flexible" is used to refer to a chamber that can be easily bent without bending or breaking. For example, at least a portion of the chamber 20 is made of silicone or fluoroelastomer, in particular a thermosetting fluoroelastomer (e.g., Viton®), or other polymer(s), that can withstand a temperature of at least 80°C, preferably a temperature between 85°C and 95°C, more preferably a temperature between 88°C and 92°C. In particular, a fast acting silicone spray or Viton® wire or other polymers can be used to build the walls of the chamber 20, for example according to the portion of the metal part 1000 to be repaired. Advantageously, this allows a perfect adaptation of the chamber 20 to the geometric shape of the portion of the metal part 1000 to be repaired. In particular, the chamber 20 can conform to many different shapes, geometries and dimensions of the metal part 1000, such as edges, ducts and parts that are typically difficult to access. With non-limiting reference to Figure 2, the inlet 21 and outlet 22 are located on the sides of the chamber 20, specifically small holes that can accommodate ducts, which are preferably sealed to the inlet 21 and outlet 22. Additionally or alternatively, the inlet 21 and / or outlet 22 may accommodate the needle of a syringe, for example a needle made of a plastic material or inox steel.

[0018] The system 100 or 200 may further comprise a fastening member 15 or 25, such as, for example, an adhesive or a magnet or a weight, configured to fastenably connect the chamber 10 or 20 to the metal part 1000. If the chamber is rigid, for example in the form of a jar as shown in FIG. 1, the opening of the jar that is connected to the metal part 1000 may have a magnetic strip along its edge so that the chamber 10 may be fastenably connected to the metal part 1000. It should be noted that if the metal part 1000 is planar, for example in the form of a plate, the chamber 10 may be placed on the metal part 1000 and fastenably connected to the metal part 1000 by a weight. For example, if the chamber is flexible, especially in the form of a sheet as shown in FIG. 2, the edge of the sheet may be fastenably connected to the metal part 1000 by using an adhesive, especially an acrylic or epoxy or vinyl adhesive.

[0019] The system 100 or 200 may further include a sealing member attached to the chamber 10 or 20 and configured to surround a portion of the metal component 1000 .

[0020] As already mentioned, the volume V of the chamber can contain different fluids, possibly fed one after the other to the chamber. In addition to the plating fluid 52, the volume V may also be configured to receive an alkaline fluid 53 (such as NaOH) and / or an acidic fluid 54 (such as dilute HCl). Advantageously, the chamber is resistant to these fluids 53 and / or 54. As will become clear below, the alkaline fluid 53 and / or the acidic fluid 54 can be used in particular to clean the surface with the alkaline fluid 53 and to activate the surface with the acidic fluid 54, in order to prepare the part of the metal part to be treated with electroless nickel plating. Advantageously, the volume V can further be configured to receive and discharge water, which can be used to clean the chamber between one fluid and the next.

[0021] With non-limiting reference to Fig. 1, the system 100 may further comprise a recirculation circuit 50 fluidly coupled to the inlet 11 and the outlet 12 of the chamber 10 and configured to recirculate the fluid from the volume V back to the volume V. In particular, the recirculation circuit 50 comprises at least one pump 51 for pumping the fluid in the recirculation circuit 50 and tanks 62, 63 and 64 for storing the fluid. For example, the recirculation circuit may have a common inlet duct in which the pump 51 is arranged and fluidly coupled to the inlet 11, and a common outlet duct fluidly coupled to the outlet 12. The different circuit branches may be fluidly coupled to the inlet and outlet ducts in which the tanks 62, 63 and 64 of different fluids are respectively arranged. Advantageously, the chamber 10 operates under a slight vacuum such that the pump 51 draws the fluid from the outlet 12 of the chamber and returns it to the tanks 62, 63 and 64. This also allows for better stability and adhesion of the chamber 10 to the portion of the metal component 1000 being repaired, especially compared to operation under overpressure. It is noted that the system 100 may also comprise further taps or valves (not shown) associated with the different circuit branches and allowing and / or not allowing the passage of fluids in the circuit branches. In other words, each tank 62, 63, and 64 is independently fluidly coupled to the inlet 11 and configured to store a particular fluid. In particular, each tank 62, 63, 64 is configured to store a different fluid.

[0022] Advantageously, the recirculation circuit 50 may further comprise a particulate filter (not shown) which may filter out solid particles that may be present in or generated in one or more of the fluids 52, 53, 54 during the process.

[0023] According to another aspect, the subject matter disclosed herein relates to a method for electroless nickel plating a portion of a metal component. With non-limiting reference to Figures 1-3, the method includes: B) covering a portion of the metal part 1000 with a chamber 10 (see block 320 of FIG. 3 ) to define a closed volume V; C) bonding the chamber 10 to the metal part 1000 (see block 330 of FIG. 3); F) supplying plating fluid 52 into volume V through an inlet of chamber 10 (see block 360 of FIG. 3); G) discharging plating fluid 52 from volume V through the outlet of chamber 10, 20 (see block 370 of FIG. 3); H) removing the chamber 10 from the metal part 1000 (see block 380 of FIG. 3).

[0024] As already mentioned, the metal part may be covered with a rigid or flexible chamber, depending for example on the shape of the metal part or the location of the part to be covered on the metal part, for example, if step B is performed on a corner of the metal part, a flexible chamber, preferably in the form of a sheet or shell, may be used. Preferably, step C is performed by means of a fastening member of the chamber, in particular an adhesive or a magnet or a weight.

[0025] It should be noted that steps F and G may be performed once or repeated multiple times. Advantageously, steps F and G are performed simultaneously, such that plating fluid is continuously supplied to and discharged from chamber volume V.

[0026] 3, the method may further comprise a step D of supplying a cleaning fluid into the volume V through an inlet of the chamber (see block 340 of FIG. 3) and a step E of draining the cleaning fluid from the volume V through an outlet of the chamber (see block 350 of FIG. 3). Advantageously, steps D and E are performed before step F to prepare the part of the metal component before the supply of the plating fluid, e.g. to clean and / or activate the surface of the part.

[0027] It should be noted that steps D and E may be performed once or may be repeated multiple times. Advantageously, steps D and E are performed simultaneously, so that the cleaning fluid is continuously supplied to and continuously drained from the chamber volume V. Also, in some cases, the repetitions of steps D and E are performed with different cleaning fluids. For example, a first time step D and E may be performed with an alkaline fluid, a second time step D and E may be performed with water, and a third time step D and E may be performed with an acidic fluid.

[0028] Furthermore, steps D, E, F, and G may be performed sequentially, i.e. without removing the chamber from the metal part, so that the treated portion of the metal part is not exposed to air between one step of the method and the next, thus avoiding oxidation of said portion, which could result in, for example, defects.

[0029] With non-limiting reference to Figure 3, the method may further comprise a step A (see block 310 in Figure 3) of treating said portion of the metal part with a chemical and / or mechanical treatment. In particular, step A may achieve cleaning of said portion of the metal part 1000, for example by supplying a suitable solvent or alkaline detergent into the volume V, resulting in degreasing. Alternatively, cleaning may be achieved by grit blasting. Typically, step A is performed before step B.

[0030] With non-limiting reference to FIG. 3, the method may further include a step I (see block 390 in FIG. 3) of heating the portion of the metal part. In particular, step I starts before or during step F and ends during or after step G, so that, at least during steps F and G, the portion is heated to at least 80° C., preferably to 85° C.-95° C., more preferably to 88° C.-92° C. Note that the portion of the metal part may be heated, for example, by induction, using resistance, using infrared lamps, or using an oxyacetylene flame. In particular, when a flame is used, heat is preferably applied to the other side of the metal part to be plated. Advantageously, one or more of the tanks 62, 63, 64, and / or one or more of the fluids 52, 53, 54, and / or the recirculation circuit 50 may also be heated.

[0031] It should also be noted that heating step I (see block 390 in FIG. 3 ) can be conceptually divided into three steps: a first step of initiating heating (see block 390-1 in FIG. 3 ), a second step of maintaining the heating specifically to maintain that portion of the metal part at the desired temperature (see block 390-2 in FIG. 3 ), and a step of stopping the heating (see block 390-3 in FIG. 3 ).

Claims

1. 1. A system (100, 200) for electroless nickel plating of a portion of a metal component (1000), comprising: a chamber (10, 20) having an inlet (11, 21) and an outlet (12, 22), the chamber (10, 20) being adapted to be fixedly connected to the metal part (1000) such that the part of the metal part (1000) and the chamber (10, 20) together define a closed volume (V), the inlet (11, 21) is configured to supply at least a first fluid (52) to the volume (V); the first fluid is a plating fluid (52), and the portion of the metal component (1000) is exposed to the plating fluid (52) for plating; the outlet (12, 22) is configured to discharge the first fluid (52) from the volume (V); The system (100, 200), wherein the first fluid (52) is continuously supplied and discharged.

2. The system (100) according to claim 1, wherein the chamber (10) is rigid, in particular in the form of a bowl or a jar.

3. The system (200) according to claim 1, wherein the chamber (20) is flexible, in particular in the form of a sheet or shell.

4. The system (100) of claim 1, wherein at least a portion of the chamber (10) is made of glass or a metal or metal alloy.

5. The system (200) of claim 1, wherein at least a portion of the chamber (20) is made of a silicone or fluoroelastomer or polymer capable of withstanding a temperature of at least 80°C, preferably a temperature between 85°C and 95°C, and more preferably a temperature between 88°C and 92°C.

6. The system (100, 200) of claim 1, wherein at least a portion of the chamber (10, 20) is made of a transparent or translucent material.

7. The system (100, 200) of claim 1, further comprising a fastening member (15, 25), in particular an adhesive or a magnet or a weight, configured to fastenably couple the chamber (10, 20) to the portion of the metal part (1000).

8. The system (100, 200) of claim 1, further comprising a sealing member attached to the chamber (10, 20) and configured to surround the portion of the metal component (1000).

9. 2. The system (100) of claim 1, further comprising a recirculation circuit (50) fluidly coupled to the inlet (11) and the outlet (12) and configured to recirculate at least the first fluid (52) from the volume (V) back to the volume (V).

10. The recirculation circuit (50) comprises: a pump (51) for pumping at least said plating fluid (52) in said recirculation circuit (50); The system (100, 200) of claim 9, comprising at least a first tank (62) for storing said plating fluid (52).

11. a recirculation circuit (50) configured to recirculate at least one second fluid (53, 54) from said volume (V) back to said volume (V); the at least one second fluid is an alkaline fluid (53) or an acidic fluid (54); The system (100) of claim 9, wherein the chamber (10) is resistant to the at least one second fluid (53, 54).

12. The system (100, 200) of claim 11, wherein the recirculation circuit (50) further comprises at least a second tank (63, 64) for storing the at least one second fluid (53, 54).

13. 1. A method for electroless nickel plating a portion of a metal component (1000), comprising: B) covering (320) said portion of said metal part (1000) with a chamber (10, 20) so as to define a closed volume (V); C) bonding (330) said chamber (10, 20) to said metal part (1000); F) supplying (360) a plating fluid (52) into said volume (V) through an inlet of said chamber (10, 20); G) discharging (370) said plating fluid (52) from said volume (V) through an outlet of said chamber (10, 20); H) removing (380) the chamber (10, 20) from the metal part (1000), A method wherein steps F and G are performed simultaneously.

14. a step D (340) of supplying a washing fluid (53, 54) into said volume (V) through an inlet of said chamber (10, 20) and a step E (350) (53, 54) of discharging said washing fluid from said volume (V) through an outlet of said chamber (10, 20), 14. The method of claim 13, wherein said step D (340) and said step E (350) are performed before said step F (360).

15. The method further comprises a step A (310) of treating the portion of the metal part (1000) with a chemical and / or mechanical treatment, Step A (310) is performed before step B (320); The method of claim 13, wherein the chemical and / or mechanical treatment provides cleaning of the portion of the metal component (1000).

16. The method further comprises a step I (390) of heating the portion of the metal part (1000); Step I (390) begins before or during step F (360) and ends during or after step G (370); 14. The method of claim 13, wherein during step I (390), the portion of the metal component (1000) is heated to at least 80°C, preferably to 85°C to 95°C, more preferably to 88°C to 92°C.

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