Composite plating solution, preparation method of composite plating layer and electrical contact material

Abstract

This application discloses a composite plating solution, a method for preparing a composite coating, and an electrical contact material. The composite plating solution includes a water-soluble silver-containing compound, cyanide, graphene, a rare earth oxide, a dispersant, a wetting agent, and water. The rare earth oxide includes at least one of lanthanum oxide, yttrium oxide, and cerium oxide. This application aims to address the poor solder resistance of existing silver coatings.

Description

Technical Field

[0001] The present application relates to the field of electroplating solutions, and in particular to a composite plating solution, a method for preparing a composite coating, and an electrical contact material. Background Art

[0002] Electrical contact materials are the core components and key materials of electrical switches. They are responsible for connecting and disconnecting circuits and load currents. The material properties determine the breaking capacity and contact reliability of electrical switches.

[0003] To ensure good conductivity, electrical contact materials are typically plated with silver on the surface of their substrates. However, traditional silver plating has low hardness and poor resistance to welding, making it difficult to meet the practical needs of rapidly developing electrical equipment. Summary of the Invention

[0004] In view of this, the present application provides a composite plating solution, a method for preparing a composite plating layer, and an electrical contact material, aiming to solve the problem of poor resistance to fusion welding of existing silver plating layers.

[0005] The embodiment of the present application is implemented as follows:

[0006] The present application provides a composite plating solution, comprising a water-soluble silver-containing compound, cyanide, graphene, rare earth oxide, a dispersant, a wetting agent and water, wherein the rare earth oxide comprises at least one of lanthanum oxide, yttrium oxide and cerium oxide.

[0007] Optionally, in some embodiments of the present application, the rare earth oxides are yttrium oxide and lanthanum oxide, and the weight ratio of the yttrium oxide to the lanthanum oxide is 1:7-9; or,

[0008] The rare earth oxides are yttrium oxide and cerium oxide, and the weight ratio of the yttrium oxide to the cerium oxide is 1:6-8; or,

[0009] The rare earth oxides are yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of the yttrium oxide, the cerium oxide and the lanthanum oxide is 1:1-1.5:5-8.

[0010] Optionally, in some embodiments of the present application, the weight ratio of the graphene to the rare earth oxide is 1:1.2-3; and / or,

[0011] The particle size of the rare earth oxide is 10-120 nm.

[0012] Optionally, in some embodiments of the present application, the wetting agent includes at least two of 1,3,6-naphthalenetrisulfonic acid sodium salt, sodium dodecylbenzenesulfonate, lignin sulfonate, and alkyl sulfonic acid succinate; and / or,

[0013] The dispersant includes at least one of sodium salt of naphtholsulfonic acid formaldehyde condensate, sodium naphthalenesulfonate formaldehyde condensate, sodium salt of carboxylic acid and styrenesulfonic acid copolymer, sodium dialkylsulfosuccinate, sodium lauryl sulfate, and polyoxyethylene alkyl aryl ether.

[0014] Optionally, in some embodiments of the present application, the weight ratio of the wetting agent to the dispersant is 1:1-2; and / or,

[0015] The cyanide includes at least one of potassium cyanide and sodium cyanide.

[0016] Optionally, in some embodiments of the present application, in the composite plating solution:

[0017] The concentration of the silver ions is 5-10 g / L; and / or,

[0018] The concentration of the graphene is 0.3-0.8 g / L; and / or,

[0019] The wetting agent concentration is 0.3-2 g / L; and / or,

[0020] The dispersant concentration is 0.3-3.5 g / L; and / or,

[0021] The concentration of the cyanide is 90-210 g / L; and / or,

[0022] The pH value of the composite plating solution is 7.5-10.5.

[0023] Optionally, in some embodiments of the present application, the composite plating solution is composed of a water-soluble silver-containing compound, cyanide, graphene, a rare earth oxide, a dispersant, a wetting agent and water, and the rare earth oxide is composed of at least one of lanthanum oxide, yttrium oxide and cerium oxide.

[0024] In a second aspect, the present application proposes a composite coating, wherein the materials of the composite coating include rare earth oxide, graphene and silver, and the rare earth oxide includes at least one of lanthanum oxide, yttrium oxide and cerium oxide.

[0025] Optionally, in some embodiments of the present application, the thickness of the composite coating is 25-40 μm; and / or,

[0026] In the composite coating, the weight ratio of the graphene to the rare earth oxide is 1:1.2-3; and / or,

[0027] The rare earth oxide is a composition of yttrium oxide and lanthanum oxide in a weight ratio of 1:7-9, a composition of yttrium oxide and cerium oxide in a weight ratio of 1:6-8, or a composition of yttrium oxide, cerium oxide and lanthanum oxide in a weight ratio of 1:1-1.5:5-8.

[0028] In a third aspect, the present application proposes a method for preparing a composite coating, comprising the following steps:

[0029] Providing a substrate and the composite plating solution as described above;

[0030] The composite plating solution is used to electroplate the surface of the substrate to obtain a composite plating layer.

[0031] Optionally, in some embodiments of the present application, during the electroplating, the temperature of the composite plating solution is 16-24° C.; and / or,

[0032] During the electroplating, the current density is 0.3~0.7A / dm 2 .

[0033] In a fourth aspect, the present application further proposes an electrical contact material, comprising a substrate and a composite coating coated on the surface of the substrate, wherein the composite coating comprises the composite coating as described above, or the composite coating is prepared by the preparation method as described above.

[0034] The composite plating solution provided in the present application includes a water-soluble silver-containing compound, cyanide, graphene, rare earth oxides, a dispersant, a wetting agent and water. By adding graphene and rare earth oxides, the composite coating prepared by the composite plating solution not only has excellent electrical conductivity, wear resistance, hardness and anti-welding performance, but also reduces the amount of silver used and reduces costs accordingly; at the same time, the rare earth oxide includes at least one of lanthanum oxide, yttrium oxide and cerium oxide. By selecting rare earth oxides that match graphene and other components, the rare earth oxides can be stably present in the plating solution; by adding dispersants and wetting agents, the graphene and rare earth oxides are assisted to be stably and evenly dispersed in the plating solution, thereby giving full play to their respective excellent properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 It is a flow chart of a method for preparing a composite coating proposed in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of the present application, the term "including" means "including but not limited to". The various embodiments of the present application may be in the form of a range; it should be understood that the description in the form of a range is only for convenience and simplicity, and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, description of a range from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, such as 1, 2, 3, 4, 5, and 6. Furthermore, whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range.

[0038] In this application, "and / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0039] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can each be single or plural.

[0040] The present invention provides a composite plating solution for preparing a composite coating. The composite plating solution includes a water-soluble silver-containing compound, cyanide, graphene, a rare earth oxide, a dispersant, a wetting agent, and water, wherein the rare earth oxide includes at least one of lanthanum oxide, yttrium oxide, and cerium oxide.

[0041] The composite plating solution proposed in this application includes a water-soluble silver-containing compound, cyanide, graphene, rare earth oxides, a dispersant, a wetting agent, and water. Graphene exhibits excellent properties such as high electrical conductivity, high thermal conductivity, high strength, high flexibility, and strong chemical inertness. The addition of graphene to the composite plating solution can enhance the arc extinguishing, resistance to welding, wear resistance, and hardness of the composite coating. The addition of rare earth oxides can also help improve the material's resistance to welding and hardness. Overall, the composite plating solution combines excellent electrical conductivity, wear resistance, hardness, and resistance to welding. Furthermore, the addition of highly conductive graphene reduces the amount of silver used, thereby lowering costs.

[0042] Graphene has poor dispersibility and easily aggregates in water, making it difficult to fully exert its performance. At the same time, the composite plating solution has poor stability. Every time an additional component is introduced, the stability of the plating solution decreases, leading to decomposition and poisoning of the plating solution. In response to the above problems, the present application carefully selects rare earth oxides that match graphene and other components, so that both graphene and rare earth oxides can exist stably in the plating solution. On the other hand, by adding dispersants and wetting agents, graphene and rare earth oxides are assisted to be stably and evenly dispersed in the plating solution, and during electroplating, they can be smoothly deposited on the surface of the substrate to form a uniformly distributed coating, thereby giving full play to the excellent properties of the two materials and greatly improving the performance of the composite coating.

[0043] In some embodiments, the rare earth oxides are yttrium oxide and lanthanum oxide, and the weight ratio of the yttrium oxide to the lanthanum oxide is 1:7~9. For example, the weight ratio of the yttrium oxide to the lanthanum oxide can be 1:7, 1:7.2, 1:7.5, 1:8, 1:8.5, 1:8.7, 1:9, etc.; by controlling the mixing ratio of the rare earth oxides, the rare earth oxides, graphene and silver ions can be well matched, and while ensuring the stability of the composite plating solution, yttrium oxide and lanthanum oxide can give full play to their excellent performance, thereby improving the hardness and resistance to welding of the composite coating.

[0044] In other embodiments, the rare earth oxides are yttrium oxide and cerium oxide, and the weight ratio of the yttrium oxide to the cerium oxide is 1:6~8. For example, the weight ratio of the yttrium oxide to the lanthanum oxide can be 1:6, 1:6.5, 1:7, 1:7.2, 1:7.5, 1:8, etc.; by controlling the mixing ratio of the rare earth oxides, the rare earth oxides, graphene and silver ions can be well matched, and while ensuring the stability of the composite plating solution, yttrium oxide and cerium oxide can give full play to their excellent performance, thereby improving the hardness and resistance to welding of the composite coating.

[0045] In some other embodiments, the rare earth oxides are yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of the yttrium oxide, the cerium oxide and the lanthanum oxide is 1:1~1.5:5~8. For example, the weight ratio of the yttrium oxide, the cerium oxide and the lanthanum oxide can be 1:1:5, 1:1.2:5, 1:1.5:5, 1:1:6, 1:1:7, 1:1:8, 1:1.5:6, 1:1.5:7, 1:1.5:8 and the like; by controlling the mixing ratio of the rare earth oxides, the rare earth oxides, graphene and silver ions can be well matched, and while ensuring the stability of the composite plating solution, the yttrium oxide, cerium oxide and lanthanum oxide can give full play to their excellent performance, thereby improving the hardness and resistance to welding of the composite coating.

[0046] In some embodiments, the concentration of the graphene is 0.3-0.8 g / L. For example, the concentration of the graphene can be 0.3 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, etc. Within this range, it helps to increase the content of graphene in the composite coating, and helps to improve the conductivity, arc extinguishing, anti-welding, wear resistance and hardness of the coating.

[0047] In some embodiments, the weight ratio of the graphene and the rare earth oxide is 1:1.2~3. For example, the weight ratio of the graphene and the rare earth oxide can be 1:1.2, 1:1.3, 1:1.5, 1:1.7, 1:2, 1:2.2, 1:2.5, 1:2.8, 1:3, etc.; this embodiment helps to ensure the dispersibility of the graphene on the one hand, and on the other hand, ensures that the graphene and rare earth oxide are evenly distributed in the coating by combining the graphene and the rare earth oxide in an appropriate proportion. Furthermore, in some embodiments, the concentration of the rare earth oxide is 0.36~2.4g / L, for example, 0.36g / L, 0.4g / L, 0.5g / L, 0.8g / L, 1g / L, 1.5g / L, 2g / L, 2.2g / L, 2.4g / L, etc. At the same time, in the composite plating solution, the concentration of the graphene can be 0.3-0.8g / L. By controlling the ratio and concentration of graphene and rare earth oxide in the plating solution, it is helpful to improve the migration rate of graphene and rare earth oxide in the plating solution during electroplating, so that the graphene and rare earth oxide migrate to the area to be electroplated quickly and at a matching speed, ensuring that the graphene and rare earth oxide are evenly distributed in the coating. At the same time, it is ensured that the graphene and rare earth oxide in the coating fully exert their respective excellent properties. The balance point is reached, while ensuring conductivity, improving hardness, anti-welding, wear resistance and other properties.

[0048] In some embodiments, the particle size of the rare earth oxide is 10~120nm. For example, the particle size can be 10~20nm, 20~50nm, 40~60nm, 60~80nm, 80~100nm, 100~120nm, etc. Within this range, it helps to evenly distribute the particles in the coating.

[0049] The addition of a wetting agent helps reduce the surface tension of graphene, allowing it to bind with the dispersant, thereby improving the dispersibility of the graphene and preventing agglomeration. Furthermore, in some embodiments, the wetting agent includes at least two of 1,3,6-naphthalenetrisulfonic acid sodium salt, sodium dodecylbenzenesulfonate, lignin sulfonate, and alkyl sulfonic acid succinate salts. When any two or more of these are used in combination, they can synergistically enhance the effect of improving the dispersibility of graphene.

[0050] The dispersant includes at least one of the following: sodium salt of naphtholsulfonic acid formaldehyde condensate, sodium naphthalenesulfonate formaldehyde condensate, sodium salt of carboxylic acid and styrenesulfonic acid copolymer, sodium dialkyl sulfosuccinate, sodium lauryl sulfate, and polyoxyethylene alkyl aryl ether; by adding the dispersant and coordinating it with the wetting agent, it helps to improve the dispersion effect of graphene and rare earth oxides in the plating solution.

[0051] In some embodiments, the wetting agent concentration is 0.3-2 g / L, for example, 0.3 g / L, 0.4 g / L, 0.5 g / L, 1 g / L, 1.5 g / L, 1.8 g / L, 2 g / L, etc. In other embodiments, the dispersant concentration is 0.3-3.5 g / L, for example, 0.3 g / L, 0.4 g / L, 0.5 g / L, 1 g / L, 1.5 g / L, 1.8 g / L, 2 g / L, 3 g / L, 3.5 g / L, etc. By controlling the wetting agent and dispersant concentrations within this range, it is helpful to improve the dispersion of the components in the plating solution, thereby ensuring a high migration rate of silver ions, rare earth oxides, and graphene in the plating solution while ensuring the stability of the plating solution.

[0052] In addition, in some embodiments, the weight ratio of the wetting agent to the dispersant is 1:1~2. For example, the weight ratio can be 1:1, 1:1.2, 1:1.3, 1:1.5, 1:1.7, 1:2, etc. This helps the wetting agent and the dispersant to better cooperate and coordinate.

[0053] The cyanide can be selected from any common cyanide in the art, for example, at least one of potassium cyanide and sodium cyanide.

[0054] In some embodiments, the concentration of the cyanide is 90-210 g / L, for example, 90 g / L, 95 g / L, 100 g / L, 105 g / L, 110 g / L, 120 g / L, 130 g / L, 150 g / L, 160 g / L, 180 g / L, 200 g / L, 210 g / L, etc. Further, in some embodiments, the cyanide is potassium cyanide, and the concentration of potassium cyanide in the composite plating solution can be 100-210 g / L.

[0055] Furthermore, in some embodiments, the water-soluble silver-containing compound may include silver nitrate. In the composite plating solution, the concentration of the silver ions is 5 to 10 g / L, for example, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, and the like.

[0056] In some embodiments, the pH of the composite plating solution is 7.5-10.5, for example, 7.5, 8, 8.5, 9, 10, 10.5, etc.

[0057] In a specific embodiment, the composite plating solution consists of a water-soluble silver-containing compound, cyanide, graphene, rare earth oxide, a dispersant, a wetting agent and water, and the rare earth oxide consists of at least one of lanthanum oxide, yttrium oxide and cerium oxide.

[0058] Furthermore, in another embodiment, the composite plating solution is composed of 5~10 g / L of silver ions, 90~210 g / L of cyanide, 0.3~0.8 g / L of graphene, 0.36~2.4 g / L of rare earth oxide, 0.3~3.5 g / L of dispersant, 0.3~2 g / L of wetting agent and water, the rare earth oxide is composed of at least one of lanthanum oxide, yttrium oxide and cerium oxide, and the weight ratio of the graphene to the rare earth oxide is 1:1.2~3.

[0059] Based on the above embodiments, the present application further proposes a method for preparing the composite plating solution. Specifically, the preparation method includes dividing water into three parts; adding cyanide and a water-soluble silver-containing compound to a part of the water, stirring and mixing to form a plating solution; adding a wetting agent to a part of the water to form a wetting agent solution; adding a dispersant to the remaining water to form a dispersant solution; adding the wetting agent solution, the dispersant solution, the graphene and the rare earth oxide to the plating solution in sequence while stirring, adjusting the pH, and preparing the composite plating solution.

[0060] In addition, the present application also proposes a composite coating, wherein the material of the composite coating includes rare earth oxide, graphene and silver, and the rare earth oxide includes at least one of lanthanum oxide, yttrium oxide and cerium oxide.

[0061] The composite coating proposed in this application includes rare earth oxides, graphene, and silver. Graphene exhibits excellent properties such as high electrical conductivity, high thermal conductivity, high strength, high flexibility, and strong chemical inertness. The addition of graphene to the composite coating improves its arc extinguishing properties, resistance to welding, wear resistance, and hardness. Furthermore, the addition of rare earth oxides helps improve the resistance to welding and hardness of the composite coating. Overall, the composite coating exhibits excellent electrical conductivity, wear resistance, hardness, and resistance to welding. Furthermore, the addition of highly conductive graphene reduces the amount of silver used, thereby lowering costs.

[0062] In some embodiments, the thickness of the composite coating is 25-40 μm.

[0063] In some embodiments, in the composite coating, the weight ratio of the graphene to the rare earth oxide is 1:1.2-3.

[0064] In some embodiments, the rare earth oxide is a composition of yttrium oxide and lanthanum oxide in a weight ratio of 1:7-9; in other embodiments, the rare earth oxide is a composition of yttrium oxide and cerium oxide in a weight ratio of 1:6-8; in still other embodiments, the rare earth oxide is a composition of yttrium oxide, cerium oxide, and lanthanum oxide in a weight ratio of 1:1-1.5:5-8.

[0065] In addition, the present invention provides a method for preparing a composite coating, see Figure 1 , the preparation method comprises the following steps:

[0066] Step S10: providing a substrate and the composite plating solution as described above.

[0067] Step S20 , electroplating the surface of the substrate with the composite plating solution to obtain a composite coating.

[0068] The substrate may be any substrate to be coated, and the material of the substrate may include but is not limited to at least one of copper, silver, gold, platinum, or alloys thereof.

[0069] The composite plating solution includes a water-soluble silver-containing compound, cyanide, graphene, rare earth oxide, a dispersant, a wetting agent and water, wherein the rare earth oxide includes at least one of lanthanum oxide, yttrium oxide and cerium oxide.

[0070] In some embodiments, during the electroplating, the temperature of the composite plating solution is 16-24°C, for example, 16°C, 17°C, 18°C, 19°C, 20°C, 22°C, 24°C, etc. In other embodiments, during the electroplating, the current density is 0.3-0.7 A / dm 2 , for example, 0.3A / dm 2 , 0.4A / dm2 , 0.5A / dm 2 , 0.6A / dm 2 , 0.7A / dm 2 etc.

[0071] In addition, the present application also proposes an electrical contact material, comprising a substrate and a composite coating coated on the surface of the substrate, wherein the composite coating comprises the composite coating as described above, or the composite coating is prepared by the composite coating preparation method described above.

[0072] The technical solutions and technical effects of the present application are described in detail below through specific embodiments, comparative examples and experimental examples. The following embodiments are only some embodiments of the present application and do not specifically limit the present application.

[0073] Example 1

[0074] (1) A composite plating solution comprises silver nitrate, potassium cyanide, graphene, rare earth oxide, a dispersant, a wetting agent, and water, wherein: the concentration of silver ions is 8 g / L, the concentration of graphene is 0.6 g / L, the concentration of rare earth oxide is 1.2 g / L, the concentration of wetting agent is 0.3 g / L, the concentration of dispersant is 0.3 g / L, the concentration of potassium cyanide is 105 g / L, and the pH of the composite plating solution is 8.5. The rare earth oxides are yttrium oxide and lanthanum oxide, and the weight ratio of yttrium oxide to lanthanum oxide is 1:8, and the particle size of the rare earth oxide ranges from 10 to 50 nm; the dispersant is sodium salt of naphtholsulfonic acid formaldehyde condensate and sodium salt of carboxylic acid and styrenesulfonic acid copolymer, and the weight ratio is 1:6; the wetting agents are sodium salt of 1,3,6-naphthalenetrisulfonic acid, lignin sulfonate, and alkylsulfonic acid succinate, and the weight ratio is 7:2:1.

[0075] (2) Preparation of composite plating solution: Divide water into three parts; add potassium cyanide and silver nitrate to one part of the water and stir to make a plating solution; add a wetting agent to one part of the water to make a wetting agent solution; add a dispersant to the remaining water to make a dispersant solution; add the wetting agent solution, dispersant solution, graphene and rare earth oxide to the plating solution in sequence while stirring, adjust the pH to 8.5, and prepare a composite plating solution.

[0076] (3) Preparation of electrical contact material: Provide a copper sheet; place the copper sheet in the composite plating solution prepared above, and set the current density to 0.7A / dm 2 ; The electroplating temperature (temperature of the composite plating solution) is 20°C, and electrodeposition is performed to obtain a composite coating with a thickness of 30 μm.

[0077] Example 2

[0078] This embodiment is basically the same as the first embodiment, except that:

[0079] The rare earth oxides are changed to yttrium oxide and lanthanum oxide, and the weight ratio of yttrium oxide to lanthanum oxide is 1:7.

[0080] Example 3

[0081] This embodiment is basically the same as the first embodiment, except that:

[0082] The rare earth oxides are changed to yttrium oxide and lanthanum oxide, and the weight ratio of yttrium oxide to lanthanum oxide is 1:9.

[0083] Example 4

[0084] This embodiment is basically the same as the first embodiment, except that:

[0085] The rare earth oxides are changed to yttrium oxide and cerium oxide, and the weight ratio of yttrium oxide to cerium oxide is 1:6.

[0086] Example 5

[0087] This embodiment is basically the same as the first embodiment, except that:

[0088] The rare earth oxides are changed to yttrium oxide and cerium oxide, and the weight ratio of yttrium oxide to cerium oxide is 1:7.

[0089] Example 6

[0090] This embodiment is basically the same as the first embodiment, except that:

[0091] The rare earth oxides are changed to yttrium oxide and cerium oxide, and the weight ratio of yttrium oxide to cerium oxide is 1:8.

[0092] Example 7

[0093] This embodiment is basically the same as the first embodiment, except that:

[0094] The rare earth oxides are changed to yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of yttrium oxide, cerium oxide and lanthanum oxide is 1:1:5.

[0095] Example 8

[0096] This embodiment is basically the same as the first embodiment, except that:

[0097] The rare earth oxides are changed to yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of yttrium oxide, cerium oxide and lanthanum oxide is 1:1.2:6.

[0098] Example 9

[0099] This embodiment is basically the same as the first embodiment, except that:

[0100] The rare earth oxides are changed to yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of yttrium oxide, cerium oxide and lanthanum oxide is 1:1.5:8.

[0101] Example 10

[0102] This embodiment is basically the same as the first embodiment, except that:

[0103] The rare earth oxides are changed to cerium oxide and lanthanum oxide, and the weight ratio of cerium oxide to lanthanum oxide is 1:7.

[0104] Example 11

[0105] This embodiment is basically the same as the first embodiment, except that:

[0106] The graphene concentration was changed from 0.6g / L to 0.8g / L; the rare earth oxide concentration was changed from 1.2g / L to 2.4g / L.

[0107] Example 12

[0108] This embodiment is basically the same as the first embodiment, except that:

[0109] The graphene concentration was changed from 0.6g / L to 0.3g / L; the rare earth oxide concentration was changed from 1.2g / L to 0.36g / L.

[0110] Example 13

[0111] This embodiment is basically the same as the first embodiment, except that:

[0112] The wetting agent is changed to a combination of 1,3,6-naphthalenetrisulfonic acid sodium salt and sodium dodecylbenzenesulfonate, and the weight ratio of the two is 1:1.

[0113] Example 14

[0114] This embodiment is basically the same as the first embodiment, except that:

[0115] The wetting agent is changed to a combination of sodium dodecylbenzenesulfonate and ligninsulfonate, and the weight ratio of the two is 2:1; the dispersant is changed to sodium naphthalenesulfonate formaldehyde condensate.

[0116] Example 15

[0117] This embodiment is basically the same as the first embodiment, except that:

[0118] The concentration of the wetting agent was changed from 0.3 g / L to 1 g / L; the concentration of the dispersant was changed from 0.3 g / L to 2 g / L; and the dispersant was changed to a composition of sodium dialkyl sulfosuccinate, sodium lauryl sulfate, and polyoxyethylene alkyl aryl ether in a weight ratio of 1:1:1.

[0119] Example 16

[0120] This embodiment is basically the same as the first embodiment, except that:

[0121] The concentration of the wetting agent was changed from 0.3 g / L to 2 g / L; the concentration of the dispersant was changed from 0.3 g / L to 3.5 g / L.

[0122] Example 17

[0123] This embodiment is basically the same as the first embodiment, except that:

[0124] The concentration of silver ions was changed from 8g / L to 5g / L; the pH of the composite plating solution was changed from 8.5 to 7.5; when preparing electrical contact materials, the current density was changed from 0.7A / dm 2 Changed to 0.3A / dm 2 , the electroplating temperature (temperature of the composite plating solution) was changed from 20°C to 16°C, and the thickness of the composite coating was changed from 30μm to 25μm.

[0125] Example 18

[0126] This embodiment is basically the same as the first embodiment, except that:

[0127] The concentration of potassium cyanide was changed from 105 g / L to 210 g / L; the concentration of silver ions was changed from 8 g / L to 10 g / L; the pH of the composite plating solution was changed from 8.5 to 10.5; when preparing electrical contact materials, the electroplating temperature (the temperature of the composite plating solution) was changed from 20°C to 24°C, and the thickness of the composite coating was changed from 30 μm to 40 μm.

[0128] Example 19

[0129] This embodiment is basically the same as the first embodiment, except that:

[0130] (1) The composite plating solution comprises silver nitrate, potassium cyanide, graphene, rare earth oxide, dispersant, wetting agent and water, wherein: the concentration of silver ion is 7 g / L, the concentration of graphene is 0.3 g / L, the concentration of rare earth oxide is 0.8 g / L, the concentration of wetting agent is 0.3 g / L, the concentration of dispersant is 0.3 g / L, the concentration of potassium cyanide is 100 g / L, and the pH of the composite plating solution is 8.5. The rare earth oxide is lanthanum oxide, and the particle size of the rare earth oxide ranges from 100 to 120 nm; the dispersant is sodium salt of naphtholsulfonic acid formaldehyde condensate and sodium salt of carboxylic acid and styrenesulfonic acid copolymer, with a weight ratio of 1:6; the wetting agent is sodium salt of 1,3,6-naphthalenetrisulfonic acid, lignin sulfonate and alkylsulfonic acid succinate, with a weight ratio of 7:2:1.

[0131] (2) Preparation of composite plating solution: Divide water into three parts; add potassium cyanide and silver nitrate to one part of the water and stir to make a plating solution; add a wetting agent to one part of the water to make a wetting agent solution; add a dispersant to the remaining water to make a dispersant solution; add the wetting agent solution, dispersant solution, graphene and rare earth oxide to the plating solution in sequence while stirring, adjust the pH to 8.5, and prepare a composite plating solution.

[0132] (3) Preparation of electrical contact material: Provide a copper sheet; place the copper sheet in the composite plating solution prepared above, and set the current density to 0.6A / dm 2 ; The electroplating temperature (temperature of the composite plating solution) is 20°C, and electrodeposition is performed to obtain a composite coating with a thickness of 28 μm.

[0133] Comparative Example 1

[0134] This comparative example is basically the same as Example 1, except that:

[0135] Subtract rare earth oxides and other components remain unchanged.

[0136] Comparative Example 2

[0137] This comparative example is basically the same as Example 1, except that:

[0138] The rare earth oxides are changed to yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of yttrium oxide, cerium oxide and lanthanum oxide is 1:1:9.

[0139] Comparative Example 3

[0140] This comparative example is basically the same as Example 1, except that:

[0141] The rare earth oxides are changed to yttrium oxide, cerium oxide and lanthanum oxide, and the weight ratio of yttrium oxide, cerium oxide and lanthanum oxide is 1:2:4.

[0142] Comparative Example 4

[0143] This comparative example is basically the same as Example 1, except that:

[0144] The rare earth oxides are changed to yttrium oxide and cerium oxide, and the weight ratio of yttrium oxide to cerium oxide is 1:9.

[0145] Comparative Example 5

[0146] This comparative example is basically the same as Example 1, except that:

[0147] The rare earth oxides are changed to yttrium oxide, cerium oxide and scandium oxide, and the weight ratio of yttrium oxide, cerium oxide and lanthanum oxide is 1:1:5.

[0148] Comparative Example 6

[0149] This comparative example is basically the same as Example 1, except that:

[0150] Rare earth oxides were changed to scandium oxide.

[0151] Comparative Example 7

[0152] This comparative example is basically the same as Example 1, except that:

[0153] The dispersant was changed to sodium lauryl sulfate.

[0154] Comparative Example 8

[0155] This comparative example is basically the same as Example 1, except that:

[0156] The wetting agent was changed to 1,3,6-naphthalenetrisulfonic acid sodium salt.

[0157] Comparative Example 9

[0158] This comparative example is basically the same as Example 1, except that:

[0159] Subtract the wetting agent and keep the other components unchanged.

[0160] Comparative Example 10

[0161] This comparative example is basically the same as Example 1, except that:

[0162] Subtract the dispersant and keep the other components unchanged.

[0163] Comparative Example 11

[0164] This comparative example is basically the same as Example 1, except that:

[0165] The dispersant was changed to BYK-110, and the other components remained unchanged.

[0166] Comparative Example 12

[0167] This comparative example is basically the same as Example 1, except that:

[0168] The concentration of rare earth oxides was changed from 1.2 g / L to 3 g / L.

[0169] Comparative Example 13

[0170] This comparative example is basically the same as Example 1, except that:

[0171] Subtract graphene and keep other components unchanged.

[0172] Comparative Example 14

[0173] This comparative example is basically the same as Example 1, except that:

[0174] Minus graphene, rare earth oxides, dispersants and wetting agents.

[0175] Experimental Example 1

[0176] The zeta potentials of the composite plating solutions prepared in Examples 1-18 and Comparative Examples 2-11 were measured, and the absolute values ​​of the measured zeta potentials were recorded in Table 1.

[0177] Table 1

[0178]

[0179] From Table 1 we can see that:

[0180] Compared to Comparative Examples 2-6, each Example exhibited a higher absolute value of the zeta potential, demonstrating that the composite plating solution prepared in the Examples exhibited improved dispersibility and stability. This demonstrates that the use of at least one of yttrium oxide, cerium oxide, and lanthanum oxide as a rare earth oxide, added to the composite plating solution in a specific ratio, ensures the compatibility of all components in the plating solution and ensures plating solution stability. Furthermore, compared to Comparative Example 12, Example 1 exhibited higher dispersibility, demonstrating that the addition of rare earth oxides at a weight ratio of 1:1.2 to 3 of graphene to rare earth oxides helps improve the dispersibility of substances in the plating solution.

[0181] Compared with Comparative Examples 7-11, each embodiment has a higher absolute value of zeta potential, indicating that the composite plating solution prepared in the embodiment has better dispersibility and stability. It shows that by selecting a specific combination of dispersants and wetting agents, the present application can achieve good synergistic effects between different dispersants and between dispersants and wetting agents, which helps to improve the dispersibility and stability of the plating solution.

[0182] Experimental Example 2

[0183] The properties of the composite coatings prepared in Examples 1-19 and Comparative Examples 1, 12-14 were tested, including wear resistance, welding resistance, and hardness of the composite coatings. The results are recorded in Table 2.

[0184] Table 2

[0185]

[0186] From Table 2 we can see that:

[0187] Compared with Comparative Examples 1, 13, and 14, the composite coatings prepared in Examples 1-19 all exhibited higher hardness, wear resistance, and resistance to fusion welding, indicating that the composite plating solution proposed in this application, by simultaneously adding graphene and rare earth oxides, greatly improved the hardness, wear resistance, and resistance to fusion welding of the coating.

[0188] Comparing Examples 1-10 and 19, the composite coatings prepared in Examples 1 to 3 have higher hardness, wear resistance, and resistance to fusion welding, indicating that the use of yttrium oxide and lanthanum oxide as rare earth oxides added to the composite plating solution in this application can not only ensure that all components are compatible with the plating solution and ensure the stability of the plating solution, but also effectively improve the hardness, wear resistance, and resistance to fusion welding of the coating.

[0189] By comparing Example 1 and Comparative Example 12, it can be seen that the hardness, wear resistance and welding resistance of Example 1 are better than those of the comparative example, indicating that by controlling the rare earth oxide within the range of 0.36~2.4g / L, not only the stability of the plating solution can be improved, but also the comprehensive performance of the coating can be improved.

[0190] The above is a detailed introduction to the composite plating solution, the preparation method of the composite coating and the electrical contact material provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A composite plating solution, characterized in that The method comprises a water-soluble silver-containing compound, cyanide, graphene, rare earth oxide, a dispersant, a wetting agent and water, wherein the rare earth oxide is yttrium oxide and lanthanum oxide, or yttrium oxide and cerium oxide, or yttrium oxide, cerium oxide and lanthanum oxide; The concentration of the graphene is 0.3-0.8 g / L; the concentration of the rare earth oxide is 0.36-2.4 g / L; and the weight ratio of the graphene to the rare earth oxide is 1:1.2-3.

2. The composite plating solution according to claim 1, wherein When the rare earth oxides are yttrium oxide and lanthanum oxide, the weight ratio of the yttrium oxide to the lanthanum oxide is 1:7-9; or When the rare earth oxides are yttrium oxide and cerium oxide, the weight ratio of the yttrium oxide to the cerium oxide is 1:6-8; or When the rare earth oxides are yttrium oxide, cerium oxide and lanthanum oxide, the weight ratio of the yttrium oxide, the cerium oxide and the lanthanum oxide is 1:1-1.5:5-8.

3. The composite plating solution according to claim 1, wherein The particle size of the rare earth oxide is 10-120 nm.

4. The composite plating solution according to claim 1, wherein The wetting agent includes at least two of 1,3,6-naphthalenetrisulfonic acid sodium salt, sodium dodecylbenzenesulfonate, lignin sulfonate, and alkyl sulfonic acid succinate; and / or, The dispersant includes at least one of sodium salt of naphtholsulfonic acid formaldehyde condensate, sodium naphthalenesulfonate formaldehyde condensate, sodium salt of carboxylic acid and styrenesulfonic acid copolymer, sodium dialkylsulfosuccinate, sodium lauryl sulfate, and polyoxyethylene alkyl aryl ether.

5. The composite plating solution according to claim 1, wherein The weight ratio of the wetting agent to the dispersant is 1:1-2; and / or, The cyanide includes at least one of potassium cyanide and sodium cyanide.

6. The composite plating solution according to claim 1, characterized in that In the composite plating solution: The concentration of silver ions is 5-10 g / L; and / or, The wetting agent concentration is 0.3-2 g / L; and / or, The dispersant concentration is 0.3-3.5 g / L; and / or, The concentration of the cyanide is 90-210 g / L; and / or, The pH value of the composite plating solution is 7.5-10.

5.

7. The composite plating solution according to claim 1, characterized in that The composite plating solution consists of a water-soluble silver-containing compound, cyanide, graphene, rare earth oxide, a dispersant, a wetting agent and water, and the rare earth oxide consists of at least one of lanthanum oxide, yttrium oxide and cerium oxide.

8. A method for preparing a composite coating, characterized in that: The following steps are involved: Providing a substrate and the composite plating solution according to any one of claims 1 to 7; The composite plating solution is used to electroplate the surface of the substrate to obtain a composite plating layer.

9. The preparation method according to claim 8, characterized in that During the electroplating, the temperature of the composite plating solution is 16-24° C.; and / or, During the electroplating, the current density is 0.3~0.7A / dm 2 .

10. An electrical contact material, characterized in that: The invention comprises a substrate and a composite coating coated on the surface of the substrate, wherein the composite coating is prepared by the preparation method according to claim 8 or 9.

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