Multi-layer composite electroplating grinding wheel and preparation method thereof

Abstract

The invention discloses a multi-layer composite electroplating grinding wheel and a preparation method thereof, and belongs to the technical field of super-hard grinding tool manufacturing. The grinding wheel comprises a metal matrix, a transition coating and a composite working coating, and the transition coating is a nickel-phosphorus alloy coating and is tightly attached to the outer circumferential surface of the metal matrix; the composite working coating is divided into a coarse grinding layer and a fine grinding layer in the radial direction, the coarse grinding layer adopts 50-80 [mu] m diamond abrasive (the volume ratio is 35-45%), the fine grinding layer adopts 10-30 [mu] m diamond / cubic boron nitride mixed abrasive (the volume ratio is 20-30%), and an annular laser groove is formed in the surface of the fine grinding layer. The preparation method comprises the steps of substrate pretreatment, pulse electroplating of the transition layer, preparation of the coarse grinding layer through ultrasonic-mechanical synergistic dispersion, preparation of the fine grinding layer through parameter adjustment and laser groove machining. Coarse grinding and fine grinding are integrated, the bonding strength of a plating layer is improved by 40% or above, the surface roughness of a workpiece after fine grinding is smaller than or equal to Ra 0.1 micron, the service life of a grinding wheel is prolonged by 1.5-2 times, and the method is suitable for efficient and precise machining of hard and brittle materials.

Description

Technical Field

[0001] This invention relates to the field of cutting equipment technology, specifically to a multi-layer composite electroplated grinding wheel and its preparation method. Background Technology

[0002] Electroplated grinding wheels are widely used in precision grinding due to their strong abrasive holding power and high machining accuracy. In existing technologies, most electroplated grinding wheels employ a single-layer abrasive coating structure. Although some technologies have improved abrasive uniformity to some extent by optimizing the electroplating system, they still have significant shortcomings in balancing grinding efficiency and machining quality. A single abrasive particle size cannot simultaneously meet the high-efficiency material removal requirements of the roughing stage and the low surface roughness requirements of the finishing stage. This leads to frequent wheel replacements when machining high-precision workpieces, significantly reducing production efficiency.

[0003] Meanwhile, traditional electroplated grinding wheels often suffer from insufficient bonding between the metal substrate and the abrasive coating. During high-speed rotary grinding, the alternating stress and thermal shock can easily lead to coating delamination and peeling, affecting machining accuracy and posing safety hazards. Furthermore, current electroplating processes rely on a single mechanical stirring method for abrasive dispersion, resulting in poor stability and localized abrasive agglomeration. This leads to uneven wear on the grinding wheel's working surface and shortens its service life. With the increasing demands for workpiece machining accuracy and efficiency in fields such as semiconductors and optics, developing a multi-layered composite electroplated grinding wheel that combines high-efficiency grinding, precision machining, and long service life has significant practical and industrial application value. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a multi-layer composite electroplated grinding wheel and a method for preparing the same, in order to solve the problem.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A multi-layer composite electroplated grinding wheel includes a metal substrate, a transition coating, and a composite working coating. The transition coating is tightly attached to the outer circumferential surface of the metal substrate, and the composite working coating covers the outer side of the transition coating. The composite working coating is radially divided into a coarse grinding layer and a fine grinding layer from the inside to the outside. The abrasive volume ratio in the coarse grinding layer is 35-45%, and the abrasive volume ratio in the fine grinding layer is 20-30%. The abrasive particle size in the coarse grinding layer is larger than that in the fine grinding layer. The transition coating is a nickel-phosphorus alloy coating with a thickness of 5-15 μm.

[0007] Preferably, the abrasive of the coarse grinding layer is diamond particles with a particle size of 50-80 μm, and the abrasive of the fine grinding layer is a mixture of diamond and cubic boron nitride particles with a mixing mass ratio of 3:1, and the abrasive particle size of the fine grinding layer is 10-30 μm.

[0008] Preferably, the metal substrate is 45 steel or aluminum alloy with a surface roughness Ra≤0.4μm.

[0009] Preferably, the total thickness of the composite working coating is 100-200 μm, wherein the thickness of the coarse grinding layer accounts for 60-70% and the thickness of the fine grinding layer accounts for 30-40%; the phosphorus content in the transition coating is 8-12%.

[0010] Preferably, the surface of the polished layer is provided with laser-processed grooves, which are distributed in a ring shape, with a groove width of 50-100μm, a groove depth of 20-40μm, and a spacing of 200-300μm between adjacent grooves.

[0011] The preparation method of the above-mentioned multi-layer composite electroplated grinding wheel includes the following steps:

[0012] Step 1: Substrate pretreatment, the metal substrate is subjected to degreasing, pickling and activation treatment in sequence to remove the surface oxide layer and impurities;

[0013] Step 2: Preparation of transition coating. The pretreated metal substrate is placed in a nickel-phosphorus alloy electroplating solution, and a transition coating is deposited using a pulse electroplating process.

[0014] Step 3: Preparation of coarse abrasive layer. Replace the electroplating solution and add coarse abrasive. Use ultrasonic-mechanical synergistic dispersion to make the abrasive uniformly suspended and continuously electroplating to form a coarse abrasive layer on the outside of the transition coating.

[0015] Step 4: Preparation of the fine grinding layer. Adjust the composition of the electroplating solution and the type of abrasive, control the abrasive suspension concentration, and continue electroplating to form a fine grinding layer on the outside of the coarse grinding layer.

[0016] Step 5: Grooving. The finely ground layer of the composite working coating is subjected to laser grooving, cleaning, and drying to obtain the finished product.

[0017] Preferably, in step 1, the pickling uses a 10-15% sulfuric acid solution at a temperature of 40-50°C for 3-5 minutes; the activation treatment uses a 5-8% hydrochloric acid solution for 1-2 minutes.

[0018] Preferably, the pulse electroplating parameters in step 2 are: current density 3-5 A / dm³. 2 The pulse frequency is 500-800Hz, the duty cycle is 40-60%, the electroplating temperature is 55-65℃, the pH value is 4.0-4.5, and the electroplating time is 10-20min.

[0019] Preferably, the electroplating solution for the coarse abrasive layer in step 3 comprises: 250-300 g / L nickel sulfate, 30-40 g / L nickel chloride, 35-45 g / L boric acid, 0.1-0.3 g / L sodium dodecyl sulfate, and 1-3 g / L saccharin; the amount of abrasive added is 80-120 g / L, the ultrasonic power is 200-300 W, and the mechanical stirring speed is 300-500 r / min.

[0020] Preferably, in step 4, the electroplating solution for the fine grinding layer is prepared by adding 0.5-1.5 g / L of 1,4-butynediol to the electroplating solution for the coarse grinding layer, the abrasive addition is 40-60 g / L, and the current density is reduced to 2-3 A / dm³. 2 The electroplating temperature is maintained at 50-60℃.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. Significantly improved adhesion: The nickel-phosphorus alloy transition coating increases the adhesion strength between the substrate and the working coating by more than 60%, solving the problem of coating peeling. The adhesion of this invention can reach more than 25 MPa.

[0023] 2. Balancing processing efficiency and precision: The coarse grinding layer efficiently removes material, while the fine grinding layer achieves precision machining, reducing the surface roughness of the workpiece to Ra≤0.1μm. At the same time, the grinding efficiency is increased by 40% compared to single-layer grinding wheels, making it suitable for composite processing needs such as semiconductor wafer thinning.

[0024] 3. Extended lifespan: The uniform distribution of abrasive and the groove chip removal design extend the service life of the grinding wheel by more than 2 times, reducing processing costs.

[0025] 4. Stable process: The combination of ultrasonic-mechanical synergistic dispersion and pulse electroplating process improves the uniformity of abrasive distribution by 50%, with D90 / D10≤1.5, ensuring consistency in mass production.

[0026] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings.

[0027] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0029] Figure 1 This is a schematic diagram of the structure of the present invention;

[0030] Figure 2 This is a cross-sectional view of the composite working coating in this invention;

[0031] Figure 3 This is a flowchart of the method of the present invention.

[0032] In the diagram: 1. Metal substrate; 2. Transition coating; 3. Composite working coating; 4. Fine grinding layer; 5. Coarse grinding layer; 6. Groove. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. In the following description, specific details such as specific configurations and components are provided merely to help fully understand the embodiments of this application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. In addition, for clarity and brevity, descriptions of known functions and structures are omitted in the embodiments.

[0034] Furthermore, reference numerals and / or letters may be repeated in different examples within this application. Such repetition is for the purpose of simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or settings discussed.

[0035] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" in this article describes another type of relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the related objects before and after it are in an "or" relationship.

[0036] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion.

[0037] Please see Figure 1-3 This invention provides a technical solution for a multi-layer composite electroplated grinding wheel and its preparation method:

[0038] Example 1: Preparation of multilayer composite electroplating grinding wheel for semiconductor wafer processing

[0039] Substrate pretreatment: Select a φ100mm No. 45 steel substrate and proceed as follows:

[0040] ①Alkaline degreasing (sodium hydroxide 50g / L, sodium carbonate 30g / L, temperature 60℃, 10min);

[0041] ② Sulfuric acid pickling (12% sulfuric acid solution, 45℃, 4min);

[0042] ③ Activation with hydrochloric acid (6% hydrochloric acid solution, 1.5 min), the surface Ra of the substrate after treatment is ≤0.4 μm.

[0043] Transition plating layer preparation: Prepare a nickel-phosphorus alloy electroplating solution (nickel sulfate 280 g / L, sodium hypophosphite 30 g / L, sodium citrate 50 g / L), adjust the pH to 4.2, set the temperature to 60℃, and use pulse electroplating parameters: current density 4 A / dm³. 2 The frequency was 600 Hz, the duty cycle was 50%, and the electroplating time was 15 minutes to form a 10 μm thick transition coating. The phosphorus content was detected to be 10%.

[0044] Preparation of coarse abrasive layer: Replace the electroplating solution (nickel sulfate 280g / L, nickel chloride 35g / L, boric acid 40g / L, sodium dodecyl sulfate 0.2g / L, saccharin 2g / L), add 100g / L of 50-80μm diamond abrasive, turn on ultrasonic (250W) and mechanical stirring (400r / min), current density 4A / dm2, electroplating for 40min to form a 100μm coarse abrasive layer.

[0045] Preparation of the fine grinding layer: Add 1 g / L of 1,4-butynediol to the electroplating solution of the coarse grinding layer, replace with 50 g / L of a mixed abrasive of 20-30 μm diamond and cubic boron nitride (mass ratio 3:1), and reduce the current density to 2.5 A / dm². 2 Electroplating for 25 minutes forms a 50μm fine polished layer.

[0046] Post-processing: Grooves were machined on the surface of the finely ground layer using a fiber laser processing machine. The grooves were 80μm wide, 30μm deep, and 250μm apart. After ultrasonic cleaning, the surface was dried at 80℃ to obtain the finished product.

[0047] Finished product inspection: The bonding strength of the transition coating is 28MPa, the abrasive volume ratio of the coarse grinding layer is 40%, the abrasive volume ratio of the fine grinding layer is 25%, the abrasive distribution D90 / D10 = 1.4, when used for wafer thinning, the grinding efficiency reaches 15μm / min, the workpiece surface roughness Ra = 0.08μm, and the service life reaches 800 pieces / wheel, which is 2.2 times higher than the existing single-layer grinding wheel.

[0048] Example 2: Preparation of multilayer composite electroplated grinding wheel for optical glass processing

[0049] The difference from Example 1 is that the metal substrate is made of aluminum alloy, the abrasive in the fine grinding layer is a single 10-20μm cubic boron nitride abrasive, and the groove spacing is 200μm. When the finished product is used for optical glass grinding, the surface roughness reaches Ra=0.05μm, making it suitable for high-precision optical component processing.

[0050] The core innovation of this invention lies in the multi-layer composite structure design and synergistic preparation process. The phosphorus content of the transition coating, the abrasive ratio of the working coating, and the electroplating parameters can be adjusted according to the processing object. For example, when processing cemented carbide, the abrasive particle size of the coarse grinding layer can be increased to 80 μm, and the current density can be increased to 5 A / dm. 2 All implementation methods must ensure that the thickness of the transition coating is not less than 5μm to ensure bonding strength. The abrasive dispersion adopts an ultrasonic-mechanical synergistic method to avoid agglomeration problems caused by single dispersion.

[0051] The above description is merely a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. A multi-layer composite electroplated abrasive wheel, characterized by, It comprises a metal base (1), a transition plating layer (2) and a composite working plating layer (3), the transition plating layer (2) is closely attached to the outer circumferential surface of the metal base (1), and the composite working plating layer (3) covers the outside of the transition plating layer (2); the composite working plating layer (3) is sequentially divided into a coarse grinding layer (5) and a fine grinding layer (4) from inside to outside along the radial direction, the abrasive volume ratio in the coarse grinding layer (5) is 35-45%, the abrasive volume ratio in the fine grinding layer (4) is 20-30%, and the abrasive particle size of the coarse grinding layer (5) is larger than that of the fine grinding layer (4); the transition plating layer (2) is a nickel-phosphorus alloy plating layer with a thickness of 5-15 μm.

2. The multi-layer composite electroplated abrasive wheel of claim 1, wherein, The abrasive of the coarse grinding layer (5) is diamond particles with a particle size of 50-80 μm, and the abrasive of the fine grinding layer (4) is mixed particles of diamond and cubic boron nitride with a mixing mass ratio of 3:1, and the abrasive particle size of the fine grinding layer (4) is 10-30 μm.

3. The multi-layer composite electroplated abrasive wheel of claim 1, wherein, The metal base (1) is 45 steel or aluminum alloy, and the surface roughness Ra is ≤0.4 μm.

4. The multi-layer composite electroplated abrasive wheel of claim 1, wherein, The total thickness of the composite working plating layer (3) is 100-200 μm, wherein the thickness ratio of the coarse grinding layer (5) is 60-70%, and the thickness ratio of the fine grinding layer (4) is 30-40%; the content of phosphorus in the transition plating layer (2) is 8-12%.

5. The multi-layer composite electroplated abrasive wheel of claim 1, wherein, The surface of the fine grinding layer (4) is provided with laser-processed grooves (6), the grooves (6) are annularly distributed, the groove width is 50-100 μm, the groove depth is 20-40 μm, and the distance between adjacent grooves (6) is 200-300 μm.

6. A method for producing a multi-layer composite electroplated abrasive wheel for producing an abrasive wheel according to any one of claims 1 to 5, characterized in that It comprises the following steps: Step 1: base pretreatment, sequentially performing oil removal, pickling, and activation treatment on the metal base (1) to remove the surface oxide layer and impurities; Step 2: transition plating layer preparation, placing the pretreated metal base (1) in a nickel-phosphorus alloy electroplating solution, and depositing the transition plating layer (2) by using pulse electroplating process; Step 3: coarse grinding layer preparation, replacing the electroplating solution and adding coarse grinding abrasive, uniformly suspending the abrasive by ultrasonic-mechanical synergistic dispersion, and continuously electroplating on the outside of the transition plating layer (2) to form the coarse grinding layer (5); Step 4: fine grinding layer preparation, adjusting the composition of the electroplating solution and the type of abrasive, controlling the suspended concentration of the abrasive, and continuously electroplating on the outside of the coarse grinding layer (5) to form the fine grinding layer (4); Step 5: groove processing, laser groove (6) processing, cleaning, and drying on the fine grinding layer (4) of the composite working plating layer (3) to obtain the finished product.

7. The preparation method according to claim 6, characterized in that, In step 1, the pickling adopts 10-15% sulfuric acid solution with a temperature of 40-50 ℃ and a treatment time of 3-5 min; the activation treatment adopts 5-8% hydrochloric acid solution with a treatment time of 1-2 min.

8. The preparation method according to claim 6, characterized in that, The pulse plating parameters in step 2 are: current density 3-5 A / dm 2 , pulse frequency 500-800 Hz, duty cycle 40-60%, plating temperature 55-65°C, pH value 4.0-4.5, plating time 10-20 min.

9. The preparation method according to claim 6, characterized in that, In step 3, the coarse grinding layer electroplating solution comprises: 250-300 g / L nickel sulfate, 30-40 g / L nickel chloride, 35-45 g / L boric acid, 0.1-0.3 g / L sodium dodecyl sulfate, and 1-3 g / L saccharin; the abrasive addition amount is 80-120 g / L, the ultrasonic power is 200-300 W, and the mechanical stirring speed is 300-500 r / min.

10. The method of claim 6, wherein, The fine polishing layer plating solution in Step 4 is based on the coarse polishing layer plating solution, 1,4-butynediol is added at 0.5-1.5 g / L, the abrasive is added at 40-60 g / L, and the current density is reduced to 2-3 A / dm 2 , and the plating temperature is maintained at 50-60 °C.

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