Electroplated tungsten wire diamond wire and preparation method thereof

Abstract

The present application relates to an electroplated tungsten wire diamond wire and a preparation method thereof. The preparation method performs a thermal diffusion treatment after the pre-plating treatment step and before the sanding step, wherein the electroplating solution used in the pre-plating treatment includes at least hydrogen ions and nickel ions, and the hydrogen ion concentration is 2mol / L-3mol / L, and the nickel ion concentration is 0.4mol / L-0.5mol / L; the thermal diffusion treatment includes: under protective gas conditions, a single DC current is applied to the pre-plated wire body, and the wire body is heated to 1100℃-1300℃ for thermal diffusion. The preparation method described in the present application can form a metal bond structure between the interface of the nickel coating and the tungsten wire substrate, improve the bonding force, and ensure that the coating bonding force is greater than the external shear force, thereby significantly reducing the risk of coating peeling.

Description

Technical Field

[0001] The present application relates to the field of electroplating technology, and in particular to an electroplated tungsten diamond wire and a preparation method thereof. Background Art

[0002] The most widely used process at present is the electroplated carbon steel wire diamond wire process. By consolidating diamond powder on the carbon steel wire, the coating has good diamond consolidation ability and excellent matrix bonding ability, ensuring that the carbon steel wire diamond wire coating has good cutting ability during the silicon wafer wire cutting process.

[0003] The production process of electroplated carbon steel wire diamond wire includes pre-treatment, pre-plating, sanding, thickening and post-treatment. Among them, pre-plating is to immerse the steel wire substrate after the first process into the pre-plating tank, and electro-deposit a thin layer of matrix nickel metal coating on the steel wire. Since the steel wire substrate and the nickel coating can form a metal bond and mechanical interlocking force, the bonding force between the carbon steel wire and the nickel coating is excellent. On the one hand, it can prevent the mechanical properties of the steel wire substrate from being damaged and avoid hydrogen embrittlement of the steel wire substrate; on the other hand, the composite coating and the bottom coating are bonded to the substrate through the matrix nickel metal, so that the subsequent diamond abrasive grains of sanding are more firmly bonded to the steel wire substrate.

[0004] However, as the process of thinning is progressing, the tensile strength of carbon steel wires gradually cannot meet the requirements of thinning, so tungsten wires have become the main trend of future industrial development. However, since the atomic numbers of nickel and tungsten are 28 and 74 respectively, and the crystal structures are face-centered cubic and body-centered cubic respectively, the tungsten wire and nickel coating only have the mechanical force generated by embedding, and the bonding force is reduced, resulting in problems such as coating peeling after the nickel coating on the surface of the tungsten wire is damaged. Summary of the invention

[0005] Based on this, it is necessary to provide a tungsten electroplated diamond wire and a preparation method thereof to address the above-mentioned problems; the preparation method can form a metal bond structure between the interface of the nickel plating and the tungsten wire substrate, thereby improving the bonding force and ensuring that the bonding force of the coating is greater than the external shear force, thereby significantly reducing the risk of coating peeling.

[0006] A method for preparing an electroplated tungsten diamond wire, comprising: pre-treatment, pre-plating treatment, sanding, and thickening, wherein a thermal diffusion treatment is performed after the pre-plating treatment step and before the sanding step;

[0007] The electroplating solution used in the pre-plating treatment includes at least hydrogen ions and nickel ions, the hydrogen ion concentration is 2mol / L-3mol / L, and the nickel ion concentration is 0.4mol / L-0.5mol / L;

[0008] The thermal diffusion treatment comprises: applying a single direct current to the pre-plated wire under protective gas conditions to heat the wire to 1100° C.-1300° C. for thermal diffusion.

[0009] In one embodiment, the chloride ion concentration in the electroplating solution is 0.03 mol / L-0.05 mol / L.

[0010] In one embodiment, the electroplating solution further includes aminosulfonate ions and / or rare earth ions.

[0011] In one embodiment, the components of the electroplating solution include 100mL / L-120mL / L sulfuric acid, 60g / L-110g / L nickel sulfamate, 20g / L-60g / L boric acid, 1g / L-10g / L nickel chloride and 5g / L-15g / L rare earth additives.

[0012] In one embodiment, the rare earth additive includes at least one of nano cerium chloride.

[0013] In one embodiment, the current of the pre-plating treatment is 4A-5A;

[0014] And / or, the line speed of the pre-plating treatment is 35m / min-45m / min;

[0015] And / or, after the pre-plating treatment, the thickness of the nickel plating layer is 0.5 μm-0.6 μm.

[0016] In one embodiment, the pre-plated anode is selected from an iridium-plated titanium plate, and the cathode is selected from a mercury slip ring.

[0017] In one embodiment, the pre-plating process further includes adding a nickel supplement agent, the nickel ion concentration in the nickel supplement agent is 0.28 mol / L-0.34 mol / L, and the addition rate of the nickel supplement agent is 0.5 L / min-0.6 L / min.

[0018] In one embodiment, in the thermal diffusion treatment step, the constant voltage is set to 20V-30V;

[0019] And / or, the routing speed of the thermal diffusion treatment is 35m / min-45m / min;

[0020] And / or, the thermal diffusion treatment time is 0.3s-0.6s.

[0021] A tungsten electroplated diamond wire is prepared by the method for preparing the tungsten electroplated diamond wire as described above.

[0022] Compared with the traditional electroplating carbon steel wire diamond wire process, the preparation method described in the present application, after the pretreatment step and before the sanding step, pre-plates the tungsten wire substrate in an electroplating solution with a special component content. Under the condition of a hydrogen ion concentration of 2mol / L-3mol / L, hydrogen ions form a double electric layer near the cathode, which increases the cathode overpotential, increases the nucleation rate of nickel atoms at the cathode, and limits the growth rate, thereby refining the grains of the nickel plating layer and increasing the contact area with the tungsten wire substrate, thereby improving the bonding strength between the tungsten wire substrate and the nickel plating layer. Then, a single DC current is used to rapidly heat the tungsten wire substrate, and nickel atoms diffuse in the electrodeposition interface layer to form a metal diffusion layer, so that the nickel atoms are solid dissolved in the tungsten wire substrate and form metal bonds with the nickel plating layer, further improving the bonding strength.

[0023] Therefore, based on the synergistic effect of the pre-plating treatment and thermal diffusion treatment provided in this application, a metal bond structure can be formed between the interface of the nickel coating and the tungsten wire substrate, thereby improving the bonding strength and ensuring that the coating bonding strength is greater than the external shear force, thereby significantly reducing the risk of coating peeling. DETAILED DESCRIPTION

[0024] In order to facilitate understanding of the present application, the present application will be described in more detail below. However, it should be understood that the present application can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art belonging to the technical field of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific implementation methods or embodiments, and are not intended to limit the present application. The optional range of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the any and all combinations include any combination of two related listed items, any more related listed items, or all related listed items.

[0026] The present application provides a method for preparing an electroplated tungsten diamond wire, comprising the following steps:

[0027] S1, pre-treatment;

[0028] S2, pre-plating treatment, wherein the electroplating solution used in the pre-plating treatment includes at least hydrogen ions and nickel ions, the hydrogen ion concentration is 2mol / L-3mol / L, and the nickel ion concentration is 0.4mol / L-0.5mol / L;

[0029] S3, thermal diffusion treatment: under protective gas conditions, a single DC current is applied to the pre-plated wire body to raise the temperature of the wire body to 1100℃-1300℃ for thermal diffusion;

[0030] S4, upper sand;

[0031] S5, thickened.

[0032] In step S1, the impurities and pollutants on the surface of the tungsten wire substrate can be removed by pretreatment, which is beneficial to improve the bonding strength between the tungsten wire substrate and the nickel plating layer. It is understandable that the pretreatment can adopt existing conventional processes, which are not limited in this application, such as chemical degreasing, water washing, acid washing, etc.

[0033] In step S2, the tungsten wire substrate is pre-plated in an electroplating solution with a special component content. Under the condition of a hydrogen ion concentration of 2mol / L-3mol / L, hydrogen ions form a double electric layer near the cathode, which increases the cathode overpotential, increases the nucleation rate of nickel atoms at the cathode, and limits the growth rate, thereby refining the grains of the nickel coating and increasing the contact area with the tungsten wire substrate, thereby improving the bonding strength between the tungsten wire substrate and the nickel coating.

[0034] It will be appreciated that the hydrogen ion concentration includes but is not limited to any point value among 2mol / L, 2.1mol / L, 2.2mol / L, 2.3mol / L, 2.4mol / L, 2.5mol / L, 2.6mol / L, 2.7mol / L, 2.8mol / L, 2.9mol / L, 3mol / L or a range between any two of them.

[0035] The nickel ion concentration includes but is not limited to any point value among 0.4mol / L, 0.41mol / L, 0.42mol / L, 0.45mol / L, 0.46mol / L, 0.47mol / L, 0.48mol / L, 0.5mol / L or any range value between two of them.

[0036] In one embodiment, the chloride ion concentration in the plating solution includes but is not limited to any point value among 0.02mol / L, 0.03mol / L, 0.04mol / L, 0.05mol / L, 0.06mol / L, 0.07mol / L or a range value between any two of them, preferably 0.03mol / L-0.05mol / L.

[0037] In one embodiment, the electroplating solution also includes aminosulfonate ions and / or rare earth ions, wherein the aminosulfonate ions can generate a large number of active hydrogen atoms during the electrodeposition process, and utilize the strong activity and strong reducing property of the active hydrogen atoms to destroy the residual oxide film to expose the surface lattice of the tungsten filament substrate, so that the electrodeposited nickel atoms can better combine with the tungsten filament substrate, thereby greatly improving the bonding strength between the nickel coating and the tungsten filament substrate; and the rare earth ions can provide crystallization nucleation sites, which is beneficial to make the nickel coating grains finer and increase the contact area with the tungsten filament substrate, thereby further improving the bonding strength between the tungsten filament substrate and the nickel coating.

[0038] Preferably, the rare earth ions include but are not limited to at least one of cerium ions, lanthanum ions and ruthenium ions, preferably cerium ions.

[0039] In one embodiment, the components of the electroplating solution include 100 mL / L-120 mL / L sulfuric acid, 60 g / L-110 g / L nickel sulfamate, 20 g / L-60 g / L boric acid, 1 g / L-10 g / L nickel chloride, and 5 g / L-15 g / L rare earth additives.

[0040] More preferably, the components of the electroplating solution include 100 mL / L-120 mL / L sulfuric acid, 60 g / L-80 g / L nickel sulfamate, 30 g / L-50 g / L boric acid, 3 g / L-8 g / L nickel chloride and 8 g / L-12 g / L rare earth additives.

[0041] Wherein, the rare earth additive includes but is not limited to at least one of nano cerium chloride, nano cerium oxide, and nano ruthenium oxide, preferably nano cerium chloride.

[0042] In one embodiment, the current of the pre-plating treatment includes but is not limited to any point value among 2A, 3A, 4A, 5A, 6A, 7A or a range value between any two of them, preferably 4A-5A.

[0043] In one embodiment, the line speed of the pre-plating treatment includes but is not limited to any point value among 20m / min, 30m / min, 40m / min, 50m / min, 60m / min, 70m / min or any range value between two of them, preferably 35m / min-45m / min.

[0044] In one embodiment, the pre-plating process further includes adding a nickel supplementing agent, which is beneficial to maintaining the dynamic balance of nickel ions in the electroplating solution, thereby ensuring the stability of the process production.

[0045] Specifically, the nickel ion concentration in the nickel supplement includes but is not limited to any point value among 0.1mol / L, 0.2mol / L, 0.3mol / L, 0.4mol / L, 0.5mol / L, 0.6mol / L or a range value between any two of them, preferably 0.28mol / L-0.34mol / L; the addition rate of the nickel supplement includes but is not limited to any point value among 0.2L / min, 0.3L / min, 0.4L / min, 0.5L / min, 0.6L / min, 0.7L / min or a range value between any two of them, preferably 0.5L / min-0.6L / min; the nickel supplement is preferably a nickel hydroxide suspension.

[0046] The present application does not limit the electrode materials used in the pre-plating treatment, wherein the anode includes but is not limited to sulfur-nickel beads or iridium-plated titanium plates, and the cathode is selected from a mercury slip ring. Preferably, the anode is selected from an iridium-plated titanium plate, and the cathode is selected from a mercury slip ring, which is beneficial to ensure the stability of the process production.

[0047] It should be noted that the thickness of the nickel coating obtained by the pre-plating treatment varies according to the production process requirements and the diameter of the tungsten wire substrate material. Usually, the nickel coating is about 0.5 μm-3 μm, and the preferred thickness in this application is 0.5 μm-0.6 μm.

[0048] In step S3, under the condition of protective gas, it is helpful to prevent the nickel coating from being oxidized to form nickel oxide under high temperature conditions, which makes the coating brittle. Under the impact of a single DC current, the tungsten wire substrate is rapidly heated and the nickel atoms diffuse in the electrodeposition interface layer to form a metal diffusion layer, so that the nickel atoms are dissolved in the tungsten wire substrate, thereby forming a metal bond with the nickel coating, further improving the bonding strength.

[0049] It is understandable that the present application does not limit the protective gas, and the protective gas can be selected from at least one of nitrogen, helium, and argon. Nitrogen is preferred in the present application.

[0050] In one embodiment, in the thermal diffusion treatment step, the constant voltage is set to include but is not limited to any point value among 10V, 15V, 20V, 25V, 30V, 35V or a range value between any two of them, preferably 20V-30V.

[0051] In one embodiment, the routing speed of the thermal diffusion treatment includes but is not limited to any point value among 20m / min, 30m / min, 40m / min, 50m / min, 60m / min, 70m / min or any range value between two of them, preferably 35m / min-45m / min.

[0052] In one embodiment, the time of the thermal diffusion treatment includes but is not limited to any point value among 0.1s, 0.3s, 0.5s, 0.7s, 0.9s, 1.1s or any range value between two of them, preferably 0.3s-0.6s.

[0053] In step S4, the diamond abrasive grains can be firmly bonded to the surface of the pre-plated tungsten wire substrate by sanding. This process is a key process that affects the arrangement of abrasive grains on the surface of the tungsten wire substrate and the performance of the electroplated tungsten wire diamond wire.

[0054] It is understandable that the plating process can be carried out by using the existing conventional process, which is not limited in the present application. For example, the plating solution used in the plating process includes 90 g / L nickel sulfamate, 30 g / L boric acid and 0.5 g / L nickel chloride hexahydrate, wherein the pH is 3.5-5.5, the temperature is 45°C-60°C, and the cathode current density is 1.0 A / dm 2 -5.5A / dm 2 , 700g / L corundum (0.5μm-6.5μm), and mechanically stirred.

[0055] In step S5, since the nickel coating covering the microparticles on the surface of the tungsten wire substrate during sanding is generally thin, the holding force of the nickel coating on the diamond abrasive can be improved by placing the sanded tungsten wire substrate into a plating tank without diamond abrasives for nickel coating thickening electroplating.

[0056] It is understandable that the thickening can adopt the existing conventional process, and the present application does not limit this. For example, the plating solution used for thickening includes 90g / L nickel sulfamate, 30g / L boric acid and 5g / L nickel chloride hexahydrate, wherein the pH is 3.5-5.5, the temperature is 45℃-60℃, and the cathode current density is 1.0A / dm 2 -5.5A / dm 2 , 700g / L corundum (0.5μm-6.5μm), and mechanically stirred.

[0057] In one embodiment, after the thickening step, post-processing is also included. The post-processing can adopt existing conventional processes, which are not limited in the present application. For example, post-processing can be performed by water washing, heating to remove hydrogen, etc.

[0058] The present application also provides an electroplated tungsten wire diamond wire, which is prepared by the preparation method of the electroplated tungsten wire diamond wire as described above. Compared with the tungsten wire wire produced by conventional electroplating, the electroplated tungsten wire diamond wire prepared by the preparation method provided by the present application has a breaking force increased by about 0.24N, a tensile strength increased by about 229MPa, and the bonding strength of the coating is effectively improved.

[0059] The electroplated tungsten diamond wire and the preparation method thereof will be further described by the following specific examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be considered to limit the scope of the present application. If no specific conditions are specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are followed. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0060] Example 1

[0061] (1) Pretreatment: A tungsten wire with a diameter of 32.5 μm was selected as the substrate and electrolytically washed with 4% sodium hydroxide to remove the surface graphite emulsion and oxide film.

[0062] (2) Pre-plating treatment: 100 mL / L sulfuric acid, 60 g / L nickel sulfamate, 20 g / L boric acid, 5 g / L nickel chloride, and 10 g / L nano-cerium chloride were used as the electroplating solution. In the electroplating solution, the hydrogen ion concentration was 2 mol / L, the nickel ion concentration was 0.4 mol / L, and the chloride ion concentration was 0.038 mol / L. The iridium-plated titanium plate was used as the anode and the mercury slip ring was used as the cathode. The electroplating was carried out under the condition of 4.23 A current. The wire speed of the tungsten wire was 40 m / min. At the same time, nickel hydroxide suspension was added at a flow rate of 0.6 L / min during the electroplating process. The nickel ion concentration in the nickel hydroxide suspension was 0.28 mol / L. The pre-plated wire was prepared. The thickness of the nickel plating layer on the surface of the pre-plated wire was about 0.59 μm.

[0063] (3) Thermal diffusion treatment: Under nitrogen conditions, a single DC current of 24 V is applied to the pre-plated wire to heat the wire to 1100°C for thermal diffusion. The wire speed of the tungsten wire is 40 m / min and the diffusion time is 0.5 s.

[0064] (4) Sand: 90 g / L nickel sulfamate, 30 g / L boric acid and 0.5 g / L nickel chloride hexahydrate, pH 4.5, temperature 45 °C, cathode current density 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0065] (5) Thickening: 90 g / L nickel sulfamate, 30 g / L boric acid, and 5 g / L nickel chloride hexahydrate, with a pH of 4.5, a temperature of 45 °C, and a cathode current density of 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0066] (6) Post-processing: After thickening is completed, continue with water washing, drying and air cutting to ensure that the surface of the wire remains dry.

[0067] Example 2

[0068] (1) Pretreatment: A tungsten wire with a diameter of 34.5 μm was selected as the substrate and electrolytically washed with 4% sodium hydroxide to remove the surface graphite emulsion and oxide film.

[0069] (2) Pre-plating treatment: 105 mL / L sulfuric acid, 65 g / L nickel sulfamate, 30 g / L boric acid, 10 g / L nickel chloride, and 15 g / L nano-cerium chloride were used as the electroplating solution. In the electroplating solution, the hydrogen ion concentration was 2.2 mol / L, the nickel ion concentration was 0.45 mol / L, and the chloride ion concentration was 0.04 mol / L. The iridium-plated titanium plate was used as the anode and the mercury slip ring was used as the cathode. The electroplating was carried out under the condition of 4.11 A current. The wire speed of the tungsten wire was 35 m / min. At the same time, nickel hydroxide suspension was added at a flow rate of 0.53 L / min during the electroplating process. The nickel ion concentration in the nickel hydroxide suspension was 0.30 mol / L. The pre-plated wire was prepared. The thickness of the nickel plating layer on the surface of the pre-plated wire was about 0.5 μm.

[0070] (3) Thermal diffusion treatment: Under nitrogen conditions, a single DC current of 25 V is applied to the pre-plated wire to heat the wire to 1200°C for thermal diffusion. The wire speed of the tungsten wire is 35 m / min and the diffusion time is 0.6 s.

[0071] (4) Sand: 90 g / L nickel sulfamate, 30 g / L boric acid and 0.5 g / L nickel chloride hexahydrate, pH 4.5, temperature 45 °C, cathode current density 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0072] (5) Thickening: 90 g / L nickel sulfamate, 30 g / L boric acid, and 5 g / L nickel chloride hexahydrate, with a pH of 4.5, a temperature of 45 °C, and a cathode current density of 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0073] (6) Post-processing: After thickening is completed, continue with water washing, drying and air cutting to ensure that the surface of the wire remains dry.

[0074] Example 3

[0075] (1) Pretreatment: A tungsten wire with a diameter of 36.5 μm was selected as the substrate and electrolytically washed with 4% sodium hydroxide to remove the surface graphite emulsion and oxide film.

[0076] (2) Pre-plating treatment: 110 mL / L sulfuric acid, 70 g / L nickel sulfamate, 25 g / L boric acid, 10 g / L nickel chloride, and 15 g / L nano-cerium chloride were used as the electroplating solution. In the electroplating solution, the hydrogen ion concentration was 2.5 mol / L, the nickel ion concentration was 0.42 mol / L, and the chloride ion concentration was 0.045 mol / L. The iridium-plated titanium plate was used as the anode and the mercury slip ring was used as the cathode. The electroplating was carried out under the condition of 4.56 A current. The line speed of the tungsten wire was 35 m / min. At the same time, during the electroplating process, nickel hydroxide suspension was added at a flow rate of 0.58 L / min. The nickel ion concentration in the nickel hydroxide suspension was 0.30 mol / L. The pre-plated wire was prepared. The thickness of the nickel plating layer on the surface of the pre-plated wire was about 0.51 μm.

[0077] (3) Thermal diffusion treatment: Under nitrogen conditions, a single DC current of 25 V is applied to the pre-plated wire to heat the wire to 1200°C for thermal diffusion. The wire speed of the tungsten wire is 35 m / min and the diffusion time is 0.6 s.

[0078] (4) Sand: 90 g / L nickel sulfamate, 30 g / L boric acid and 0.5 g / L nickel chloride hexahydrate, pH 4.5, temperature 45 °C, cathode current density 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0079] (5) Thickening: 90 g / L nickel sulfamate, 30 g / L boric acid, and 5 g / L nickel chloride hexahydrate, with a pH of 4.5, a temperature of 45 °C, and a cathode current density of 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0080] (6) Post-processing: After thickening is completed, continue with water washing, drying and air cutting to ensure that the surface of the wire remains dry.

[0081] Example 4

[0082] (1) Pretreatment: A tungsten wire with a diameter of 29.5 μm was selected as the substrate and electrolytically washed with 4% sodium hydroxide to remove the surface graphite emulsion and oxide film.

[0083] (2) Pre-plating treatment: 120 mL / L sulfuric acid, 80 g / L nickel sulfamate, 30 g / L boric acid, 15 g / L nickel chloride, and 5 g / L nano-cerium chloride were used as the electroplating solution. In the electroplating solution, the hydrogen ion concentration was 3 mol / L, the nickel ion concentration was 0.5 mol / L, and the chloride ion concentration was 0.048 mol / L. The iridium-plated titanium plate was used as the anode and the mercury slip ring was used as the cathode. The electroplating was carried out under the condition of 4.22 A current. The wire speed of the tungsten wire was 45 m / min. At the same time, nickel hydroxide suspension was added at a flow rate of 0.57 L / min during the electroplating process. The nickel ion concentration in the nickel hydroxide suspension was 0.34 mol / L. The pre-plated wire was prepared. The thickness of the nickel plating layer on the surface of the pre-plated wire was about 0.49 μm.

[0084] (3) Thermal diffusion treatment: Under nitrogen conditions, a single DC current of 26 V is applied to the pre-plated wire to heat the wire to 1300°C for thermal diffusion. The wire speed of the tungsten wire is 45 m / min and the diffusion time is 0.4 s.

[0085] (4) Sand: 90 g / L nickel sulfamate, 30 g / L boric acid and 0.5 g / L nickel chloride hexahydrate, pH 4.5, temperature 45 °C, cathode current density 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0086] (5) Thickening: 90 g / L nickel sulfamate, 30 g / L boric acid, and 5 g / L nickel chloride hexahydrate, with a pH of 4.5, a temperature of 45 °C, and a cathode current density of 5 A / dm 2 , 700 g / L of corundum (0.5 μm), and mechanically stirred.

[0087] (6) Post-processing: After thickening is completed, continue with water washing, drying and air cutting to ensure that the surface of the wire remains dry.

[0088] Comparative Example 1

[0089] The difference between Comparative Example 1 and Example 1 is that 60 g / L of nickel sulfamate, 20 g / L of boric acid, 5 g / L of nickel chloride, and 10 g / L of nano cerium chloride are used as the electroplating solution, and the hydrogen ion concentration in the electroplating solution is 10 -4 mol / L, nickel ion concentration is 0.24mol / L, and chloride ion concentration is 0.038mol / L.

[0090] Comparative Example 2

[0091] The difference between Comparative Example 2 and Example 1 is that 100 mL / L sulfuric acid, 60 g / L nickel sulfamate, 20 g / L boric acid, and 5 g / L nickel chloride are used as the plating solution, and in the plating solution, the hydrogen ion concentration is 2 mol / L, the nickel ion concentration is 0.24 mol / L, and the chloride ion concentration is 0.038 mol / L.

[0092] Comparative Example 3

[0093] The difference between Comparative Example 3 and Example 1 is that the electroplating solution in the thickening step is used as the electroplating solution for the pre-plating treatment.

[0094] Comparative Example 4

[0095] The difference between Comparative Example 4 and Example 1 is that sanding is performed directly after the pre-plating treatment without thermal diffusion treatment.

[0096] The pre-plated wires and electroplated tungsten diamond wires prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to performance tests, and the test results are shown in Table 1.

[0097] Among them, the test method for breaking tension is: use an electronic universal testing machine (QT-6203DS), use a clamp to fix both ends of the wire, turn on the equipment to measure the tension when the wire breaks; the test method for tensile strength is: use a laser wire diameter meter to measure the wire diameter, and calculate the strength according to the tension and wire diameter through the strength formula.

[0098] Table 1

[0099]

[0100] According to Table 1, the breaking tension and tensile strength of the pre-plated wire and the electroplated tungsten wire diamond wire obtained in Examples 1 to 4 are significantly improved. However, in Comparative Example 1, since there is no high concentration of hydrogen ions in the electroplating solution, the ability to form a double electric layer near the cathode is weak, resulting in a breaking tension and tensile strength lower than about 197MPa in Example 1; in Comparative Example 2, since there is no nano-cerium chloride in the electroplating solution to provide nucleation sites, the breaking tension and tensile strength are lower than about 355MPa in Example 1; in Comparative Example 3, since the electroplating solution used for pre-plating uses conventional electroplating solution components, the breaking tension and tensile strength are lower than about 453MPa in Example 1; in Comparative Example 4, since no heat treatment is performed, nickel atoms do not diffuse in the electrodeposition interface layer to form a metal diffusion layer, resulting in a breaking tension and tensile strength lower than about 150MPa in Example 1.

[0101] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for preparing an electroplated tungsten diamond wire, comprising: Pre-treatment, pre-plating treatment, sanding, and thickening, characterized in that a thermal diffusion treatment is performed after the pre-plating treatment step and before the sanding step; The components of the electroplating solution used in the pre-plating treatment include 100mL / L-120mL / L of sulfuric acid, 60g / L-110g / L of nickel sulfamate, 20g / L-60g / L of boric acid, 1g / L-10g / L of nickel chloride, and 5g / L-15g / L of rare earth additives, with a hydrogen ion concentration of 2mol / L-3mol / L and a nickel ion concentration of 0.4mol / L-0.5mol / L. The thermal diffusion treatment includes: applying a single direct current to the pre-plated wire under protective gas conditions, heating the wire to 1100° C.-1300° C. and performing thermal diffusion treatment for 0.3s-0.6s.

2. The method for preparing the electroplated tungsten diamond wire according to claim 1, wherein: The chloride ion concentration in the electroplating solution is 0.03 mol / L-0.05 mol / L.

3. The method for preparing the electroplated tungsten diamond wire according to claim 1, wherein: The components of the electroplating solution include 100mL / L-120mL / L of sulfuric acid, 60g / L-80g / L of nickel sulfamate, 30g / L-50g / L of boric acid, 3g / L-8g / L of nickel chloride and 8g / L-12g / L of a rare earth additive.

4. The method for preparing the electroplated tungsten diamond wire according to claim 3, wherein: The rare earth additive includes nano cerium chloride.

5. The method for preparing the electroplated tungsten diamond wire according to claim 1, wherein: The current of the pre-plating treatment is 4A-5A; And / or, the line speed of the pre-plating treatment is 35m / min-45m / min; And / or, after the pre-plating treatment, the thickness of the nickel plating layer is 0.5 μm-0.6 μm.

6. The method for preparing an electroplated tungsten diamond wire according to claim 1, wherein: The pre-plated anode is selected from an iridium-plated titanium plate, and the cathode is selected from a mercury slip ring.

7. The method for preparing electroplated tungsten diamond wire according to claim 1, characterized in that: The pre-plating treatment process also includes adding a nickel supplement agent, the nickel ion concentration in the nickel supplement agent is 0.28 mol / L-0.34 mol / L, and the addition rate of the nickel supplement agent is 0.5 L / min-0.6 L / min.

8. The method for preparing electroplated tungsten diamond wire according to claim 1, characterized in that: In the thermal diffusion treatment step, the constant voltage is set to 20V-30V; And / or, the line speed of the thermal diffusion treatment is 35m / min-45m / min.

9. An electroplated tungsten diamond wire, characterized in that: The diamond wire is prepared by the method for preparing the electroplated tungsten wire according to any one of claims 1 to 8.

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