Plane-grinding electroplated diamond brushed sheet and preparation method thereof

Abstract

The invention discloses an electroplated diamond napping piece which comprises a diamond grinding layer, a base body and a cloth base and further comprises a middle nickel-plated layer, a microscopic concave-convex structure is formed on the surface of the base body through high-speed sand blasting grinding, direct current is adopted for electroplating, the middle nickel-plated layer is attached to the base body, and the middle nickel-plated layer is arranged on the base body. And then electroplating is conducted through pulse current, the diamond grinding layer is attached to the surface of the middle nickel plating layer, the base body is bonded to the front face of the cloth base, and fluff is planted on the back face of the cloth base. The invention further discloses a preparation method. The bonding strength of the diamond particles and the base material is enhanced through the middle plating layer, and the diamond particles can be uniformly distributed through electroplating by adopting pulse current, so that the durability and hardness of the product are effectively improved. The method is suitable for the technical field of grinding preparation.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding preparation, and particularly to an electroplated diamond flocking sheet for surface grinding and a preparation method thereof. Background Art

[0002] After years of development, the flocking sheet in coated abrasives has evolved from a simple grinding tool to an efficient and precise processing tool. Traditional flocking sheets mainly use common abrasives such as alumina and silicon carbide, which are fixed on the substrate through a resin binder and applied to the surface treatment of materials such as metals and woods. However, with the progress of industrial technology and the diversification of market demands, the deficiencies of traditional flocking sheets in terms of durability and grinding efficiency have gradually emerged. In recent years, high-performance abrasives such as ceramic particles and diamonds have been gradually introduced, significantly improving the hardness, wear resistance, and lifespan of the flocking sheet. The traditional electroplating process is to put the cleaned substrate into an electroplating solution containing metal ions and diamond particles, and use direct current for electroplating to deposit the metal ions and diamond particles on the surface of the substrate. However, due to the inability to control the unevenness of the substrate surface and the diffusion of diamond particles, deposition defects such as coarse grains, uneven coatings, and cracking and peeling of the coatings often occur, affecting the service life and usage effect of the flocking sheet. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an electroplated diamond flocking sheet for surface grinding and a preparation method thereof, which enhance the bonding strength between diamond particles and the substrate through an intermediate coating and use pulsed current for electroplating to control the uniform distribution of diamond particles, thereby effectively improving the durability and hardness of the product.

[0004] The technical solution adopted by the present invention is as follows: The present invention discloses an electroplated diamond flocking sheet for surface grinding, which includes a diamond grinding layer, a substrate, and a cloth base, and also includes an intermediate nickel plating layer. The substrate forms a microscopic uneven structure on the surface through high-speed sandblasting and grinding, and the intermediate nickel plating layer is attached to the substrate by electroplating using direct current, and then the diamond grinding layer is attached to the surface of the intermediate nickel plating layer by electroplating using pulsed current. The substrate is bonded to the front surface of the cloth base, and the back surface of the cloth base is planted with fluff.

[0005] Further, the thickness of the coating on the substrate is 115 - 150 μm.

[0006] Further, the coating includes an intermediate nickel plating layer and a diamond grinding layer, wherein the thickness of the diamond grinding layer is 30 - 50 μm, and the thickness of the intermediate nickel plating layer is 65 - 120 μm.

[0007] Further, the substrate is a metal wire mesh, and the cloth base is a man-made fiber.

[0008] Also disclosed is a preparation method of an electroplated diamond flocking sheet for surface grinding, and the steps are as follows:

[0009] S1. Substrate treatment: Place the substrate in a sandblasting machine, and treat the surface of the substrate by high-speed jetting of abrasives to form a microscopic uneven structure on the surface of the substrate;

[0010] S2. Cleaning the substrate: Ultrasonically clean and chemically clean the substrate obtained in S1 in sequence to remove oil stains, oxides and other impurities on the surface;

[0011] S3. Attachment of the intermediate nickel plating layer: Place the substrate obtained in S2 in an electroplating solution containing nickel ions for electroplating to form an intermediate nickel plating layer, and the intermediate nickel plating layer adheres to the substrate;

[0012] S4. Pulse electroplating: Place the substrate obtained in S4 in an electroplating solution containing diamond for electroplating, and use pulse current to control the electroplating process to form a diamond grinding layer, and the diamond grinding layer adheres to the substrate;

[0013] S5. Adhesion: Adhere the substrate obtained in S4 to the front side of the cloth base through an adhesive, and then dry and cure;

[0014] S6. Shaping: After implanting fluff on the back of the cloth base obtained in S5, blank and shape it.

[0015] Further, the abrasives used in S1 are alumina or quartz sand or glass beads or silicon carbide or steel sand or a mixture thereof, and the grinding treatment is carried out in a sandblasting machine at a speed of 50-70 m / s for 0.5-1 min. Among them, the diameter range of the abrasives is 0.2-0.5 mm for alumina, 0.5-1.2 mm for quartz sand, 0.1-0.3 mm for glass beads, 0.1-0.7 mm for silicon carbide, and 0.4-1.2 mm for steel sand.

[0016] Further, the electroplating solution used in S3 is a mixed solution of 280 g / L nickel sulfate (NiSO 4 ·6H 2 O), 50 g / L nickel chloride (NiCl 2 ·6H 2 O), 40 g / L boric acid (H 3 BO 3 ), 0.1 g / L wetting agent (such as sodium dodecyl sulfate), 0.3 g / L brightening agent and 0.5-1.0 g / L leveling agent (polyethylene glycol PEG or other organic additives). Direct current electroplating is carried out with a current density of 2-6 A / dm 2 , the electroplating temperature is controlled at 50-60 °C, the pH value is controlled at 4.2±0.2, and the electroplating duration can be adjusted according to the actual coating thickness, generally between 20-60 min.

[0017] Further, the electroplating solution used in S4 is a mixed liquid of nickel sulfate (NiSO 4 ), nickel chloride (NiCl 2 ), boric acid (H 3 BO 3 ) and diamond particles suspended in the solution. The pulsed current density is a peak current density of 9.5 A / dm 2 and a valley current density of 0 - 2 A / dm 2 . The pulse frequency is 800 Hz and the duty ratio is 70%.

[0018] Further, after steps S3 and S4, post - heat treatment is required. After obtaining the substrate with an intermediate nickel plating layer attached to its surface in S3, the substrate is placed in a heating device for post - heat treatment to cure the plating layer, and the heating temperature is 200 - 450 °C; after obtaining the substrate with a diamond grinding layer attached in S4, the substrate is placed in a heating device for post - heat treatment, and the heating temperature is 250 - 300 °C. The heating rate of the above post - heat treatment is controlled at 5 - 10 °C / min.

[0019] Finally, after the post - heat treatment in step S4, heat preservation treatment is also required for the substrate. The heat preservation time is adjusted according to the actual coating thickness, generally controlled at 1 - 2 hours.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: Before the coating process, the surface of the substrate is treated by the method of high - speed jet abrasives to form microscopic uneven structures on the surface of the substrate, enhancing the mechanical locking force between the surface of the substrate and nickel ions, making the intermediate nickel plating layer more firm; through electroplating, a uniform nickel layer is formed on the surface of the substrate, enhancing the bonding strength between diamond particles and the substrate, improving the overall wear resistance and corrosion resistance; the process of electroplating the diamond grinding layer is controlled by pulsed current, and by adjusting the pulse parameters, the internal stress generated during electroplating can be reduced, the porosity in the coating layer can be lowered, the compactness and flatness of the coating layer can be improved, the embedding rate of diamond particles can be increased, effectively controlling that the diamond particles can be evenly embedded into the intermediate nickel plating layer, enhancing the wear resistance and service life of the coating layer; at the same time, pulsed electroplating can effectively reduce common coating defects such as pinholes and cracks, improving the consistency and reliability of the product. Therefore, the present invention enhances the bonding strength between diamond particles and the substrate through the intermediate coating layer, and uses pulsed current for electroplating control to make the diamond particles evenly distributed, thereby effectively improving the durability and hardness of the product. Description of the Drawings

[0021] Figure 1 is the test data table of the flocked sheet of the present invention in the tensile testing machine;

[0022] Figure 2This is the comparison of the surface after the simulation of actual grinding by the flocked sheet grinding test machine of the present invention. Specific embodiments

[0023] The present invention discloses an electroplated diamond flocked sheet for surface grinding, which includes a diamond grinding layer, a substrate, and a cloth base, and further includes an intermediate nickel plating layer. The substrate forms a microscopic concave-convex structure on the surface by high-speed sandblasting, and the intermediate nickel plating layer is attached to the substrate by electroplating with direct current. Then, the diamond grinding layer is attached to the surface of the intermediate nickel plating layer by electroplating with pulsed current. The substrate is bonded to the front of the cloth base, and fluff is planted on the back of the cloth base. The thickness of the plating layer on the substrate is 115-150 μm. The plating layer includes an intermediate nickel plating layer and a diamond grinding layer. Among them, the thickness of the diamond grinding layer is 30-50 μm, and the thickness of the intermediate nickel plating layer is 65-120 μm. The substrate is a metal wire mesh, and the cloth base is a synthetic fiber. Before the coating process of the present invention, the surface of the substrate is first treated by the method of high-speed jetting abrasive, and a microscopic concave-convex structure is formed on the surface of the substrate, which enhances the mechanical locking force between the surface of the substrate and nickel ions, making the intermediate nickel plating layer more firm; the electroplating method is used to form a uniform nickel layer on the surface of the substrate, enhancing the bonding strength between diamond particles and the substrate, improving the overall wear resistance and corrosion resistance; the process of electroplating the diamond grinding layer is controlled by pulsed current, and the pulsed parameters are adjusted, which can reduce the internal stress generated during electroplating, reduce the porosity in the plating layer, improve the density and flatness of the plating layer, increase the embedding rate of diamond particles, effectively control the diamond particles to be evenly embedded in the intermediate nickel plating layer, and enhance the wear resistance and service life of the plating layer; at the same time, pulsed electroplating can effectively reduce common plating layer defects such as pinholes and cracks, improving the consistency and reliability of the product.

[0024] The present invention also discloses a preparation method, and the specific steps are as follows:

[0025] S1. Substrate treatment: Place the substrate in a sandblasting machine, and treat the surface of the substrate by high-speed jetting abrasive. The abrasive used is alumina or quartz sand or glass beads or silicon carbide or steel sand or a mixture thereof. Grind in the sandblasting machine at a speed of 50-70 m / s for 0.5-1 min. Among them, the diameter range of the abrasive, for alumina is 0.2-0.5 mm, for quartz sand is 0.5-1.2 mm, for glass beads is 0.1-0.3 mm, for silicon carbide is 0.1-0.7 mm, for steel sand is 0.4-1.2 mm, and a microscopic concave-convex structure is formed on the surface of the substrate to enhance the mechanical locking force and make the plating layer more firm;

[0026] S2. Clean the substrate: Clean the substrate obtained in S1 by ultrasonic cleaning and chemical cleaning in sequence to remove oil, oxides and other impurities on the surface;

[0027] S3. Intermediate nickel plating layer adhesion: Place the substrate obtained in S2 in an electroplating solution containing nickel ions for electroplating to form an intermediate nickel plating layer, which adheres to the substrate. The electroplating solution used is a mixed solution of nickel sulfate (NiSO 4 ·6H 2 O), nickel chloride (NiCl 2 ·6H 2 O), boric acid (H 3 BO 3 ), wetting agent, brightening agent and leveling agent. Electroplate with direct current at a current density of 2 - 6 A / dm 2 . Control the electroplating temperature at 50 - 60 °C. The electroplating duration can be adjusted according to the actual coating thickness, generally between 20 - 60 min.

[0028] S4. Pulse electroplating: Place the substrate obtained in S4 in an electroplating solution containing diamond for electroplating, and use pulsed current to control the electroplating process to form a diamond grinding layer, which adheres to the substrate;

[0029] S5. Adhesion: Adhere the substrate obtained in S4 to the front side of the cloth base through an adhesive, and then dry and cure it;

[0030] S6. Shaping: After implanting fluff on the back of the cloth base obtained in S5, blank and shape it.

[0031] In steps S3 and S4, the concentration of nickel sulfate (NiSO 4 ·6H 2 O) is usually 240 - 300 g / L, which is the main nickel source for the intermediate nickel plating layer; the concentration of nickel chloride (NiCl 2 ·6H 2 O) is usually 30 - 60 g / L, which increases the conductivity of the solution and helps improve the coating quality and coating uniformity; boric acid (H 2 BO 3) The concentration is usually 30 - 45 g / L, which plays a buffering role, stabilizes the pH value of the solution between 4 - 4.5, and improves the brightness and smoothness of the coating; The wetting agent is usually sodium dodecyl sulfate with a concentration of 0.05 - 0.1 g / L, which reduces the pinholes and bubbles on the surface of the coating and improves the smoothness of the coating; The brightening agent is usually benzene sulfonamide and propargyl alcohol, which can increase the gloss of the coating, while the leveling agent is usually o-toluenesulfonamide and 1,4-butanediol, which can fill the microscopic defects on the surface of the substrate and make the coating more flat. The concentration is adjusted according to the specific formula and requirements, usually between a few milliliters and dozens of milliliters. The electroplating duration is generally 20 - 60 min, and the specific time is adjusted according to the required coating thickness. If a thicker coating is needed, the time can be appropriately extended, but attention should be paid to preventing the stress generated during electroplating from causing the coating to crack or peel off. The electroplating temperature is generally controlled at 50 - 60 °C. Too high or too low temperature will affect the coating quality and current efficiency.

[0032] Pulse electroplating operation process;

[0033] 1. After cleaning the substrate with the intermediate nickel plating layer, connect it to the cathode in the electroplating tank. The anode is usually pure nickel to ensure that the diamond particles are evenly suspended so that they can be evenly distributed in the coating; 2. Start the pulse power supply, set the pulse parameters (such as peak current, pulse frequency, duty cycle, etc.), apply the pulse current, and start the electroplating process; 3. Continuously monitor the temperature, pH value, and metal ion concentration of the electroplating solution, and adjust if necessary to ensure the uniform distribution of diamond particles in the electroplating solution and avoid particle deposition at the bottom of the electroplating tank; 4. The electroplating time depends on the required coating thickness. The coating thickness is generally 50 - 200 microns and usually lasts for 30 minutes to 2 hours; 5. After electroplating, take the workpiece out of the electroplating tank, clean it to remove the residual plating solution on the surface, and perform drying and subsequent treatments such as heat treatment or further surface treatment to enhance the adhesion and hardness of the coating.

[0034] Pulse electroplating current parameter setting,

[0035] Pulse current density: Peak current density: Usually at 9.5 A / dm 2 , which is the maximum value of the pulse current; Valley current density: Can be set to 0 - 2 A / dm 2 , and can even be set to zero (i.e., there is no current at all for some time).

[0036] Pulse frequency:

[0037] Usually 800 Hz, that is, the number of pulses per second (the higher the frequency, the finer the deposited metal layer and the higher the coating quality)

[0038] Duty cycle:

[0039] The duty cycle refers to the proportion of the time when the current is on in the entire cycle, usually set at around 70%. (For example, if the duty cycle is 50%, the current on-time and off-time each account for half.)

[0040] Pulse time and rest time:

[0041] Pulse time: The time when the current is applied, usually from a few milliseconds to several hundred milliseconds; Rest time: The time when the current stops, usually from a few milliseconds to several hundred milliseconds, allowing the metal ions in the solution to diffuse and homogenize.

[0042] After steps S3 and S4, post-heat treatment is also required. After obtaining the substrate with the intermediate nickel plating layer attached to its surface in S3, the substrate is placed in a heating device for post-heat treatment to cure the plating layer, and the heating temperature is 200 - 450 °C; after obtaining the substrate with the diamond grinding layer attached in S4, the substrate is placed in a heating device for post-heat treatment, and the heating temperature is 250 - 300 °C. The heating rate of the above post-heat treatment is controlled at 5 - 10 °C / min. After the post-heat treatment in step S4, heat preservation treatment is also required for the substrate, and the heat preservation time is adjusted according to the actual coating thickness, generally controlled at 1 - 2 hours.

[0043] Final product inspection is as follows in the table:

[0044]

[0045] Combined with the above table and Figure 1 and Figure 2 as shown, the conclusions are as follows:

[0046] Appearance inspection mainly checks surface uniformity, particle distribution, and coating integrity. Through visual and microscopic observation, it is ensured that there are no obvious defects on the surface of the electroplated diamond honing sheet. Uniformly distributed diamond particles can ensure uniform force during the grinding process, improve the grinding efficiency and service life, and have no defects such as cracks and spalling, indicating good coating quality; Thickness measurement, the thickness gauge measures the coating thickness at multiple points, and the average thickness is obtained as 120 μm. The coating meets the design requirements, with a standard deviation of 5 μm, and the thickness is relatively uniform; Hardness test. The microhardness of the coating measured by the microhardness tester is 900 HV (Vickers hardness), indicating that the coating has good wear resistance and scratch resistance and is suitable for high-intensity grinding tasks; Adhesion test, the tensile testing machine tests the bonding strength between the coating and the substrate, and the result is 35 N / cm 2, it shows that the adhesion between the coating and the substrate is strong and there is no peeling phenomenon; for the grinding performance test, the grinding testing machine simulates the actual grinding process to test the grinding efficiency and life of the flocking sheet. A grinding efficiency of 0.5 g / min indicates that the flocking sheet can quickly remove materials, which is confirmed by SEM scanning electron microscopy. At the same time, the grinding life of 2000 cycles shows its high durability and suitability for high-frequency use; for the surface roughness test, a roughness meter measures the surface roughness of the coating, and the Ra value is 0.8 μm, indicating that the coating surface is smooth. In actual use, the surface can reduce friction and heat accumulation during the grinding process, improving the machining accuracy and surface quality; chemical composition analysis. An X-ray fluorescence spectrometer analyzes the chemical composition of the coating, showing that the coating is mainly composed of nickel (85%) and carbon (15%). Nickel provides good corrosion resistance and mechanical strength, while carbon comes from diamond particles, providing ultra-high hardness and wear resistance. The chemical composition meets the design requirements, ensuring excellent comprehensive performance of the coating.

[0047] The present invention introduces pulse electroplating technology. By periodically adjusting the frequency and intensity of the current, the distribution and bonding force of diamond particles on the substrate are optimized. This method can reduce coating defects, improve the uniformity and durability of the coating, achieve uniform distribution of diamond particles on the substrate, reduce pores and defects during electroplating, and improve the overall quality and performance of the product; a nickel-plated metal intermediate layer is newly added to improve the bonding strength between diamond particles and the substrate, enhance the overall wear resistance and durability, and ensure the stability and service life of the product in high-strength applications; the surface of the substrate of the flocking sheet is sandblasted. The surface of the substrate is cleaned and roughened by high-speed jetting of abrasives. It effectively removes surface oxides and impurities, increases surface roughness, enhances the mechanical locking force between the coating and the substrate during electroplating, and improves the bonding strength and durability of the electroplated diamond flocking sheet.

[0048] Finally, it should be emphasized that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electroplated diamond brushed sheet for surface grinding, comprising a diamond grinding layer, a matrix and a cloth base, characterized in that: It also includes an intermediate nickel-plated layer. The substrate is polished by high-speed sandblasting to form a microscopic concave-convex structure on the surface. The intermediate nickel-plated layer is attached to the substrate by electroplating using direct current, and then the diamond grinding layer is attached to the surface of the intermediate nickel-plated layer by electroplating using pulse current. The substrate is bonded to the front side of the cloth base, and the back side of the cloth base is planted with fluff.

2. The electroplated diamond brushed sheet for surface grinding according to claim 1, characterized in that: The thickness of the coating on the substrate is 115-150 μm.

3. The electroplated diamond brushed sheet for surface grinding according to claim 2, characterized in that: The plating layer comprises an intermediate nickel plating layer and a diamond grinding layer, wherein the thickness of the diamond grinding layer is 30-50 μm, and the thickness of the intermediate nickel plating layer is 65-120 μm.

4. The electroplated diamond brushed sheet for surface grinding according to claim 1, characterized in that: The substrate is a metal wire mesh, and the cloth base is artificial fiber.

5. The method for preparing a surface grinding electroplated diamond brushed sheet according to any one of claims 1 to 4, characterized in that: The following steps are included: S1, substrate treatment, placing the substrate in a sandblasting machine, treating the substrate surface by high-speed jetting of abrasives, and forming a microscopic concave-convex structure on the substrate surface; S2, cleaning the substrate, subjecting the substrate obtained in S1 to ultrasonic cleaning and chemical cleaning in sequence to remove oil stains, oxides and other impurities on the surface; S3, intermediate nickel plating layer attachment, placing the substrate obtained in S2 in an electroplating solution containing nickel ions to electroplate to form an intermediate nickel plating layer, and the intermediate nickel plating layer is attached to the substrate; S4, pulse electroplating, placing the substrate obtained in S4 into an electroplating solution containing diamond for electroplating, using a pulse current to control the electroplating process to form a diamond grinding layer, and the diamond grinding layer is attached to the substrate; S5, bonding, bonding the matrix obtained in S4 to the front side of the cloth base by means of an adhesive, and then drying and curing; S6, forming, after the back side of the cloth base obtained in S5 is implanted with pile, it is punched out and formed.

6. The preparation method according to claim 5, characterized in that: The abrasive used in S1 is aluminum oxide, quartz sand, glass beads, silicon carbide, steel sand or a mixture thereof, which is ground in a sandblasting machine at a speed of 50-70 m / s for 0.5-1 min. The diameter range of the abrasive is 0.2-0.5 mm for aluminum oxide, 0.5-1.2 mm for quartz sand, 0.1-0.3 mm for glass beads, 0.1-0.7 mm for silicon carbide and 0.4-1.2 mm for steel sand.

7. The preparation method according to claim 5, characterized in that: The plating solution used in S3 is a mixed solution of 280g / L nickel sulfate (NiSO4·6H2O), 50g / L nickel chloride (NiCl2·6H2O), 40g / L boric acid (H3BO3), 0.1g / L wetting agent (such as sodium dodecyl sulfate), 0.3g / L brightener and 0.5-1.0g / L leveler (polyethylene glycol PEG or other organic additives). The current density is 2-6A / dm 2 For direct current electroplating, the electroplating temperature is controlled at 50-60℃, the pH value is controlled at 4.2±0.2, and the electroplating time can be adjusted according to the actual coating thickness, generally between 20-60min.

8. The preparation method according to claim 5, characterized in that: The electroplating solution used in S4 is a mixture of nickel sulfate (NiSO4), nickel chloride (NiCl2), boric acid (H3BO3) and diamond particles suspended in the solution. The pulse current density is a high peak current density of 9.5A / dm 2 , low valley current density 0-2A / dm 2 , the pulse frequency is 800Hz and the duty cycle is 70%.

9. The preparation method according to claim 5, characterized in that: After step S3 and step S4, post-heat treatment is required. After obtaining a substrate with an intermediate nickel plating layer attached to the surface after S3, the substrate is placed in a heating device for post-heat treatment to solidify the coating, and the heating temperature is 200-450°C; after obtaining a substrate with a diamond grinding layer attached in S4, the substrate is placed in a heating device for post-heat treatment, and the heating temperature is 250-300°C. The heating rate of the above post-heat treatment is controlled at 5-10°C / min.

10. The preparation method according to claim 9, characterized in that: After the post-heat treatment in step S4, the substrate needs to be kept warm. The warm-keeping time is adjusted according to the actual coating thickness and is generally controlled within 1-2 hours.

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