A method for modifying the surface of a diamond and its use
Patent Information
- Application Number
- CN202611077335.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-20
- Publication Date
- 2026-09-11
AI Technical Summary
[0007]本发明针对现有电镀金刚石线锯上砂过程中金刚石颗粒易团聚、分散性差、上砂效率低的技术问题，提供一种用于电镀金刚石线锯的金刚石表面改性方法及其应用
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Abstract
Description
Technical Field
[0001] This invention relates to the field of diamond wire saw manufacturing technology, specifically to a method for modifying the diamond surface of an electroplated diamond wire saw, as well as diamond micro powder prepared by the method, an electroplating solution containing the diamond micro powder, and an electroplated diamond wire saw. Background Technology
[0002] Diamond wire saws are wire cutting tools that bond high-hardness, high-wear-resistant diamond abrasive grains to a metal wire. They are widely used for cutting hard and brittle materials such as monocrystalline silicon, polycrystalline silicon, sapphire, and silicon carbide. The preparation of electroplated diamond wire saws typically includes pre-plating, abrasive coating, and thickening steps. Among these, the abrasive coating process is the most critical, involving the deposition and bonding of diamond particles to the surface of the steel wire substrate through composite electroplating.
[0003] However, diamond microparticles are small and have high surface energy, making them prone to agglomeration in liquid systems. During the abrasive application process, agglomerated diamond particles can lead to uneven abrasive distribution on the wire saw surface, resulting in defects such as abrasive clumping, overlapping, uneven microparticle distribution, and uneven abrasive distribution, which seriously affect the cutting quality and yield of the wire saw.
[0004] To address the dispersion problem of diamond particles, existing technologies have reported the use of cationic surfactants to modify the surface of diamond. For example, diamond micropowder is placed in a cationic surfactant solution, and a positively charged film is formed on the diamond surface using electrophoresis; or chemically plated diamond micropowder is calcined, acid-washed, activated, and then dispersed using cationic surfactants. While these methods improve the dispersibility of diamond to some extent, they still have the following shortcomings: First, the modification effect of a single surfactant is limited. Although cationic surfactants can improve the dispersibility between particles through electrostatic repulsion, when the amount used is too large, the thickness of the charge layer formed on the particle surface decreases, the electrostatic repulsion weakens, and the dispersion stability deteriorates.
[0005] Secondly, the sand application efficiency of existing methods still needs to be improved. In traditional sand application processes, in order to achieve good particle distribution uniformity, a long sand application time and a high current density are often required, resulting in low production efficiency and high cost.
[0006] Third, existing technologies lack systematic research and optimization of surfactant compound systems, and fail to fully leverage the synergistic effects between different types of surfactants. Summary of the Invention
[0007] This invention addresses the technical problems of easy agglomeration, poor dispersibility, and low abrasion efficiency of diamond particles during the abrasion coating process of existing electroplated diamond wire saws. It provides a diamond surface modification method for electroplated diamond wire saws and its application. This invention significantly improves the dispersion stability and abrasion coating efficiency of nickel-plated diamond micropowder in aqueous solution through the synergistic combination of cationic and nonionic surfactants, resulting in high-quality electroplated diamond wire saws with uniform diamond particle distribution and no agglomeration.
[0008] Technical solution
[0009] In a first aspect, the present invention provides a method for modifying the surface of nickel-plated diamond for electroplated diamond wire saws, comprising the following steps: (1) Pretreatment: The nickel-plated diamond micro powder is ultrasonically cleaned with a metal cleaning agent and then rinsed with deionized water; (2) Pickling and activation: The nickel-plated diamond micro powder treated in step (1) is immersed in an acid solution and ultrasonically treated, then washed with deionized water until neutral, and dried for later use; (3) Surfactant modification: The nickel-plated diamond micro powder treated in step (2) is added to an activation solution containing cationic and nonionic surfactants for immersion and activation to obtain surface-modified nickel-plated diamond micro powder.
[0010] Preferably, the concentration of the metal cleaning agent in step (1) is 1% to 2%, and the ultrasonic cleaning time is 3 to 10 min.
[0011] Preferably, the acid solution in step (2) is a hydrochloric acid solution with a concentration of 3% to 5%, and the ultrasonic treatment time is 5 to 10 minutes.
[0012] Preferably, the temperature of the activation solution in step (3) is 50~70℃, the activation time is 20~40 min, and stirring is carried out during the activation process.
[0013] Preferably, the cationic surfactant in step (3) is a quaternary ammonium salt surfactant.
[0014] More preferably, the quaternary ammonium salt surfactant is dodecyltrimethylammonium bromide (DTAB).
[0015] Preferably, the nonionic surfactant in step (3) is a polyoxyethylene dehydrated sorbitan fatty acid ester surfactant.
[0016] More preferably, the polyoxyethylene dehydrated sorbitan fatty acid ester surfactant is Tween-80 (TW-80).
[0017] Preferably, in the activation solution of step (3), the concentration of cationic surfactant is 0.4~0.8 g / L and the concentration of nonionic surfactant is 0.1~5 ml / L.
[0018] More preferably, the concentration of the cationic surfactant is 0.5~0.7 g / L, and most preferably 0.6 g / L.
[0019] More preferably, the concentration of the nonionic surfactant is 0.2~0.5 ml / L, and most preferably 0.3 ml / L.
[0020] Preferably, the pH value of the activation solution in step (3) is 4 to 6.
[0021] Secondly, the present invention provides a surface-modified nickel-plated diamond micropowder prepared according to the above method.
[0022] The surface-modified nickel-plated diamond micropowder has an absolute zeta potential of 45~60 mV in aqueous solution.
[0023] Preferably, the surface-modified nickel-plated diamond micropowder has a Zeta potential of 50-56 mV in aqueous solution.
[0024] Thirdly, the present invention provides an electroplating solution for electroplating diamond wire saws, comprising the above-mentioned surface-modified nickel-plated diamond micro powder.
[0025] Preferably, the mass concentration of the surface-modified nickel-plated diamond micropowder in the electroplating solution is 0.2~0.5 g / L, more preferably 0.3 g / L.
[0026] Fourthly, the present invention provides a method for preparing an electroplated diamond wire saw, comprising the following steps: (1) Pretreatment of the substrate: The copper-plated steel wire substrate is successively polished, alkaline washed, acid-washed and dried; Preferably, the alkaline washing uses a metal cleaning agent solution with a concentration of 1% to 3% and is ultrasonically treated for 5 to 15 minutes; the acid washing uses a dilute hydrochloric acid solution with a concentration of 2% to 5% and is ultrasonically treated for 3 to 10 minutes.
[0027] (2) Pre-plating: The pre-treated copper-plated steel wire substrate is placed in an electroplating tank and a nickel plating layer is electroplated on its surface; Preferably, the pre-plating current density is 2~4 A / dm. 2 More preferably 3 A / dm 2 .
[0028] (3) Sand coating: The steel wire substrate after pre-plating in step (2) is placed in an electroplating solution containing nickel-plated diamond micro powder with the above-mentioned surface modification for composite electroplating and sand coating. Preferably, the current density during sand application is 1.5~3 A / dm³. 2 More preferably 2 A / dm 2 .
[0029] Preferably, the sanding time is 30~90 s, more preferably 30~60 s.
[0030] (4) Thickening: The steel wire substrate after sanding is thickened by electroplating to obtain an electroplated diamond wire saw.
[0031] Fifthly, the present invention provides an electroplated diamond wire saw prepared according to the above-described preparation method.
[0032] Preferably, the diamond particle output rate on the surface of the electroplated diamond wire saw is 150~190 particles / mm.
[0033] Preferably, the diamond particles on the surface of the electroplated diamond wire saw are evenly distributed and there is no agglomeration.
[0034] Beneficial effects
[0035] The present invention has the following beneficial effects: This invention significantly improves the dispersion stability of diamond micropowder. It employs a combination of cationic surfactant DTAB and nonionic surfactant TW-80 to synergistically modify the surface of nickel-plated diamond. DTAB, a cationic surfactant, ionizes in water to release cationic groups that adsorb onto the surface of diamond particles, increasing the surface charge density and forming a cationic layer. This layer repels the particles through electrostatic repulsion. TW-80, a nonionic surfactant, adsorbs onto the surface of diamond particles via hydrogen bonds. Its long hydrocarbon chains extend outward to form a hydrophobic protective film, reducing interparticle attraction and increasing steric hindrance. The synergistic effect of these two surfactants significantly increases the Zeta potential of the modified nickel-plated diamond from approximately 23 mV to approximately 56 mV, resulting in excellent suspension stability.
[0036] This invention significantly improves abrasive plating efficiency and shortens process time. The modified nickel-plated diamond, under the influence of an electric field, can rapidly move towards the cathode, significantly improving abrasive plating efficiency. This is achieved at a current density of 2 A / dm³. 2 Under the condition of a sand-coating time of 45 s, diamond wire saws with uniform particle distribution and no agglomeration can be prepared, compared with the traditional process without the use of surfactants (current density 3 A / dm³). 2 With a sanding time of 90 s, reduced current density, and half the sanding time, production costs are greatly reduced.
[0037] This invention improves the product quality of diamond wire saws. The electroplated diamond wire saw prepared by this invention has a uniform distribution of diamond particles on its surface, without agglomeration or stacking, and a cutting efficiency of approximately 170 particles / mm. This avoids the problems of insufficient chip space and reduced cutting quality caused by excessive abrasive agglomeration.
[0038] The process is simple and easy to industrialize. The surface modification method of this invention is easy to operate, requires little equipment, and is suitable for large-scale industrial production. Attached Figure Description
[0039] Figure 1 This is a comparison diagram of the Zeta potentials of nickel-plated diamond modified with DTAB and TW-80 in Example 1 of the present invention and unmodified nickel-plated diamond.
[0040] Figure 2 These are scanning electron microscope (SEM) images of the surface morphology of diamond wire saws after activation with different DTAB concentrations in Example 2 of this invention.
[0041] Figure 3 This is a scanning electron microscope (SEM) image of the surface morphology of a diamond wire saw after activation by combining DTAB with different concentrations of TW-80 in Example 3 of the present invention.
[0042] Figure 4 This is a graph showing the effect of different DTAB concentrations on the cutting edge rate and envelope wire diameter of a diamond wire saw in Example 2 of the present invention.
[0043] Figure 5 This is a graph showing the effect of different TW-80 concentrations on the cutting edge rate and envelope wire diameter of a diamond wire saw in Example 3 of the present invention. Detailed Implementation
[0044] The present invention will be further described below through specific embodiments, but the present invention is not limited to the following embodiments. Example
[0045] This embodiment provides a method for surface modification of nickel-plated diamond.
[0046] (1) Pretreatment: The nickel-plated diamond micro powder was ultrasonically cleaned for 3 min with 1% metal cleaning agent and then rinsed with deionized water.
[0047] (2) Pickling and activation: The nickel-plated diamond micro powder treated in step (1) is immersed in 5% HCl solution and ultrasonically treated for 5 min. After being washed with deionized water until neutral, it is dried for later use.
[0048] (3) Surfactant modification: Prepare an activation solution by adding DTAB and TW-80 to deionized water to make the concentration of DTAB 0.6 g / L and the concentration of TW-80 0.3 ml / L, and adjust the pH value to about 5. Add the nickel-plated diamond micro powder treated in step (2) to the activation solution, place it in a 60℃ constant temperature water bath and stir and soak for 30 min to obtain surface-modified nickel-plated diamond micro powder.
[0049] The Zeta potential of nickel-plated diamond before and after modification was measured using a Malvern Zetasizer Nano ZS90 particle size potentiometer. The results showed that the average Zeta potential of untreated nickel-plated diamond was approximately 23 mV; the Zeta potential of nickel-plated diamond modified with DTAB alone increased to approximately 45 mV; and the Zeta potential of nickel-plated diamond modified with a combination of DTAB and TW-80 further increased to approximately 56 mV. This indicates that the method of the present invention significantly improves the charge density and dispersion stability of the nickel-plated diamond surface. Example
[0050] This embodiment provides an experiment on the effect of different DTAB concentrations on the abrasive application effect of diamond wire saws.
[0051] Nickel-plated diamond was activated by immersing in DTAB aqueous solutions of different concentrations (0.4 g / L, 0.6 g / L, 0.8 g / L) in a 60℃ water bath for 30 min with stirring before being added to the plating solution. Copper-plated steel wire with a diameter of 42 μm was used as the substrate, and pretreatment, pre-plating (current density 3 A / dm²), and abrasive coating were performed sequentially. The abrasive coating current density was 2 A / dm², the coating time was 45 s, and the diamond powder concentration in the plating solution was 0.3 g / L.
[0052] Scanning electron microscopy (SEM) results showed that when the DTAB concentration was 0.4 g / L, very few diamond particles were deposited on the wire saw surface, with a cutting edge rate of approximately 60 particles / mm. When the DTAB concentration increased to 0.6 g / L, significantly more diamond particles were deposited on the wire saw surface, and they were evenly distributed without agglomeration, resulting in a cutting edge rate of approximately 165 particles / mm. When the DTAB concentration increased to 0.8 g / L, excessive diamond deposition occurred on the base steel wire surface, leading to agglomeration, and the cutting edge rate was approximately 260 particles / mm. Therefore, the optimal DTAB concentration is 0.6 g / L.
[0053] Example
[0054] This embodiment provides an experiment on the effect of DTAB combined with different concentrations of TW-80 on the abrasive application of diamond wire saws.
[0055] Based on the addition of 0.6 g / L DTAB to the activation solution, different concentrations of TW-80 (0.1 ml / L, 0.3 ml / L, 0.5 ml / L) were added, along with nickel-plated diamond particles. The solution was then immersed and stirred in a 60℃ constant temperature water bath for 30 min for activation. The sand-coating current density was 2 A / dm³. 2 The sanding time is 45 seconds.
[0056] Scanning electron microscopy (SEM) results showed that when the TW-80 concentration was 0.1 ml / L, the number of diamond particles deposited on the substrate steel wire surface was relatively small, with a cutting edge rate of approximately 62 particles / mm. When the TW-80 concentration increased to 0.3 ml / L, the number of diamond particles deposited on the wire saw surface increased significantly, with uniform distribution and no agglomeration, resulting in a cutting edge rate of approximately 170 particles / mm. When the TW-80 concentration increased to 0.5 ml / L, agglomeration of diamond particles deposited on the substrate steel wire surface occurred, with a cutting edge rate of approximately 270 particles / mm. Therefore, when DTAB is combined with TW-80, the optimal concentration of TW-80 is 0.3 ml / L. Example
[0057] This embodiment provides a complete preparation method for an electroplated diamond wire saw.
[0058] Substrate pretreatment: Take a 42 μm diameter copper-plated steel wire, sand it until the surface is smooth, and remove surface rust and scratches. Then, ultrasonically clean it with a 2% metal cleaning solution for 10 min, and rinse it with deionized water. Next, soak it in 3% dilute hydrochloric acid and ultrasonically clean it for 5 min, rinse it with deionized water, and dry it for later use.
[0059] Pre-plating: The pre-treated copper-plated steel wire substrate is placed in an electroplating bath at 3 A / dm. 2 The current density is used to electroplate a nickel layer on its surface.
[0060] Surfactant modification: Following the method in Example 1, the nickel-plated diamond was surface modified with an activation solution containing 0.6 g / L DTAB and 0.3 ml / L TW-80.
[0061] Sanding: Modified nickel-plated diamond micropowder is added to the electroplating solution at a concentration of 0.3 g / L. The pre-plated steel wire substrate is then placed in the electroplating solution at a concentration of 2 A / dm³. 2 The current density is 45 s.
[0062] Thickening: The steel wire substrate after sanding is thickened by electroplating to obtain an electroplated diamond wire saw.
[0063] The resulting electroplated diamond wire saw has a uniform distribution of diamond particles on its surface, with no agglomeration, a cutting edge rate of approximately 170 particles / mm, and a suitable envelope wire diameter.
[0064] Industrial applicability
[0065] The diamond surface modification method for electroplated diamond wire saws provided by this invention and its application can be widely used in the processing of hard and brittle materials such as photovoltaic silicon wafer cutting, sapphire cutting, and silicon carbide cutting. The method of this invention is simple to operate, low in cost, and has high abrasive application efficiency. The diamond wire saw products prepared are of excellent quality and have broad industrial application prospects and good economic benefits.
Claims
1. A method for preparing an electroplated diamond wire saw, characterized in that, Includes the following steps: (1) The copper-plated steel wire substrate is successively polished, alkaline washed, acid-washed and dried; (2) Place the pretreated copper-plated steel wire substrate in an electroplating tank and electroplat a nickel plating layer on its surface; (3) The steel wire substrate pre-plated in step (2) is placed in an electroplating solution containing nickel-plated diamond micro powder with surface modification as described in claim 5 for composite electroplating and sanding. (4) Thicken the steel wire substrate after sanding by electroplating to obtain electroplated diamond wire saw.
2. The preparation method according to claim 1, characterized in that, The current density for pre-plating in step (2) is 2-4 A / dm. 2 In step (3), the current density for sand application is 1.5–3 A / dm³. 2 The sanding time is 30-90 seconds.
3. A method for modifying the surface of nickel-plated diamond for use in electroplated diamond wire saws, characterized in that, Includes the following steps: (1) The nickel-plated diamond micro powder was ultrasonically cleaned with a metal cleaning agent and then rinsed with deionized water. (2) The nickel-plated diamond micro powder treated in step (1) is immersed in an acid solution and ultrasonically treated, then washed with deionized water until neutral, and dried for later use. (3) The nickel-plated diamond micro powder treated in step (2) is added to an activation solution containing cationic surfactant and nonionic surfactant for immersion and activation to obtain surface-modified nickel-plated diamond micro powder.
4. The method according to claim 3, characterized in that, The cationic surfactant mentioned in step (3) is a quaternary ammonium salt surfactant, and the nonionic surfactant is a polyoxyethylene dehydrated sorbitan fatty acid ester surfactant.
5. The method according to claim 4, characterized in that, The quaternary ammonium salt surfactant is dodecyltrimethylammonium bromide, and the polyoxyethylene dehydrated sorbitan fatty acid ester surfactant is Tween-80.
6. The method according to any one of claims 3 to 5, characterized in that, In step (3), the concentration of cationic surfactant in the activation solution is 0.4-0.8 g / L, the concentration of nonionic surfactant is 0.1-5 ml / L, the temperature of the activation solution is 50-70℃, and the activation time is 20-40 min.
7. A surface-modified nickel-plated diamond micropowder prepared by the method according to any one of claims 3 to 6, characterized in that, The surface-modified nickel-plated diamond micropowder has an absolute zeta potential of 45–60 mV in aqueous solution.