A chemical nano-grinding method based on ceramic resin composite grinding wheel

Abstract

The present invention discloses a chemical nano-grinding method based on a ceramic resin composite grinding wheel, which relates to the field of super-hard abrasive tool manufacturing and ultra-precision machining. The chemical nano-grinding method of the present invention comprises the following steps: synthesizing ultra-fine abrasive into micro-edge polymer abrasive by a spray granulation method; mixing micro-edge polymer abrasive, active metal powder, grinding wheel binder, dispersant, wetting agent and pore-forming agent to prepare a ceramic resin composite grinding wheel; and performing chemical nano-grinding on hard and brittle material workpieces by using the ceramic resin composite grinding wheel. The chemical nano-grinding method based on a ceramic resin composite grinding wheel of the present invention adopts a two-step method to prepare a ceramic resin composite grinding wheel for chemical mechanical grinding, organically combines solid-phase chemical reaction with ductile domain grinding, realizes ductile domain grinding of hard and brittle materials under large feed conditions, quickly obtains nano-level smooth surfaces with smaller machining allowances, and reduces material loss and machining costs of the machining object.

Description

Technical Field

[0001] The invention relates to the fields of superhard abrasive tool manufacturing and ultra-precision machining, and in particular to a chemical nano-grinding method based on a ceramic resin composite grinding wheel. Background Art

[0002] With the rapid development of materials science, hard and brittle materials have evolved into the third generation of wide bandgap materials. These third-generation hard and brittle materials, represented by SiC and GaN, possess properties such as high hardness, high brittleness, and high chemical stability. They play an irreplaceable role in extreme applications and can address the shortcomings of traditional silicon-based substrate materials. However, their extreme hardness and brittleness also pose significant challenges to ultra-precision machining technology. During the ultra-precision machining of substrate materials, grinding is a crucial step for efficiently flattening and thinning the workpiece surface, as well as rapidly reducing surface roughness. The quality of the ground surface is closely linked to the efficiency of the subsequent polishing process.

[0003] In conventional grinding, the workpiece is typically processed by rough grinding followed by fine grinding. During the rough grinding process, a grinding wheel made of large-grain, high-hardness abrasives is used to flatten the workpiece to obtain a smooth surface. At this stage, the workpiece surface roughness is generally high, with numerous scratches and severe surface damage. Subsequently, in the fine grinding process, a grinding wheel made of ultrafine abrasives is used to obtain a machined surface with lower surface roughness and a lower damage layer. Due to the use of both rough and fine grinding processes, the grinding wheel needs to be replaced frequently, and the dressing time is long. This prolongs the grinding process, which is contrary to the principle of efficient grinding. Furthermore, the grinding wheel is one of the most important consumables in the grinding process, and its performance directly affects the quality of the grinding process.

[0004] Currently, grinding wheels can be divided into vitrified bond grinding wheels, metal bond grinding wheels, and resin bond grinding wheels. The performance of grinding wheels made with different bonds varies greatly and are suitable for different applications or processes. Vitrified bond grinding wheels have good wear resistance, high hardness, and are not prone to heat and clogging during the grinding process. They have high grinding efficiency and stable performance and are generally used for rough grinding and semi-finishing grinding, but are relatively difficult to manufacture. Metal bond grinding wheels have good wear resistance, less wear, and a long service life, but have poor self-sharpening properties, are prone to clogging, heat, and are difficult to dress. Resin bond grinding wheels have good abrasive self-sharpening properties, low grinding forces, and low grinding temperatures. Since the resin bond has certain elasticity and polishing effects, it is suitable for occasions with low surface roughness, but has poor wear resistance. It can be seen that resin bond grinding wheels have good overall performance and can achieve the requirements of efficient and low-loss grinding and polishing of hard and brittle materials. However, they are limited by their own shortcomings such as low strength and poor wear resistance, and cannot achieve ideal processing effects.

[0005] Chinese invention patent publication number CN104690654A uses a novel pore forming method in the preparation of resin-bonded grinding wheels, obtaining uniform pores within the resin-bonded grinding wheel. The high porosity improves the chip-holding capacity of the grinding wheel. Chinese invention patent publication number CN111347354A also uses a special method to obtain a porous structure, namely a resin-bonded grinding wheel with high porosity and good self-sharpening properties. However, the wear resistance and strength of the above two resin-bonded grinding wheels are still relatively low. When processing hard and brittle materials, the grinding wheels still wear significantly and require frequent dressing. Chinese invention patent publication number CN117020980A uses a special quenching process to quench the prepared resin-bonded grinding wheels, retaining the high grinding efficiency and good self-sharpening properties of the resin-bonded grinding wheels while improving their rigidity and hardness. However, the cooling gas temperature is between -185°C and -60°C, requiring specialized gas storage equipment. Chinese invention patent publication number CN111906701A utilizes a metal / resin composite bond to produce a grinding wheel. The resulting grinding wheel combines the characteristics of both metal-bonded and resin-bonded grinding wheels. However, the hot pressing temperature during the production process reaches as high as 600°C, which hinders the resin component and other components from maintaining stable performance during the production process. In summary, existing resin-bonded grinding wheels still struggle to achieve both high strength, high wear resistance, and high-efficiency, low-damage grinding performance. Consequently, using existing resin-bonded grinding wheels to grind hard and brittle materials with high efficiency and low damage is difficult. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to propose a chemical nano-grinding method based on a ceramic resin composite grinding wheel. The ceramic resin composite grinding wheel is prepared by a two-step method, and the ductile domain grinding process under large feed conditions is realized under the dual effects of the solid-phase chemical reaction of the active metal and the nano-grinding of the ultrafine abrasive. The quasi-smooth surface is quickly obtained with a smaller machining allowance. The grinding process can be dynamically adjusted to control the solid-phase chemical reaction rate and mechanical removal efficiency, and high-efficiency and low-damage flattening grinding of single-crystal SiC can be achieved under the coupling effect.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A chemical nano-grinding method based on a ceramic resin composite grinding wheel is characterized by comprising the following steps:

[0009] S1: The ultrafine abrasive with nano-micro-edges is synthesized into large-particle micro-edge polymer abrasive by spray granulation method;

[0010] S2: Micro-edge polymer abrasive is used as grinding wheel abrasive grains and mixed with active metal, grinding wheel bond, dispersant, wetting agent and pore-forming agent to prepare a ceramic resin composite grinding wheel;

[0011] S3: Chemical nano-grinding of hard and brittle material workpieces using a ceramic resin composite grinding wheel;

[0012] S4: Dressing the dull grinding wheel with a dressing pad adsorbed with resin solvent.

[0013] Preferably, the particle size of the micro-blade polymer abrasive is 20 to 40 μm;

[0014] Preferably, the ultrafine abrasive comprises any one or more combinations of diamond, silicon carbide, aluminum oxide and boron carbide;

[0015] The particle size of the ultrafine abrasive is 0.1-5 μm.

[0016] Preferably, the active metal powder includes any one or more combinations of iron powder, aluminum powder, chromium powder, titanium powder, cobalt powder, nickel powder and zinc powder;

[0017] The particle size of the active metal powder is 0.5 to 3 μm.

[0018] The grinding wheel bond comprises the following raw materials in parts by mass: 50 to 75 parts of carbon fiber and 25 to 50 parts of resin bond; the carbon fiber has a diameter of 5 to 10 μm and a length of 20 to 200 μm;

[0019] Preferably, the resin binder is any one of phenolic resin, epoxy resin and polyimide resin.

[0020] The ceramic resin composite grinding wheel comprises the following raw materials in parts by mass: 30-70 parts of micro-edge polymer abrasive, 20-50 parts of active metal powder, 5-20 parts of grinding wheel bond, 1-10 parts of pore former, 1-5 parts of dispersant and 1-5 parts of wetting agent.

[0021] Preferably, the preparation method of the ceramic resin composite grinding wheel comprises the following steps:

[0022] (1) uniformly mixing the formulated ultrafine abrasive and the ceramic binder, smelting them at 800-1200° C. in an inert gas environment, and then spray granulating them to obtain a micro-edge polymer abrasive;

[0023] (2) After the carbon fiber and the resin binder are mixed, they are heated and stirred in a water bath to obtain a grinding wheel binder;

[0024] (3) After uniformly mixing the micro-edge polymer abrasive and active metal powder in the formula amount, a dispersant, a wetting agent and a pore-forming agent are added, and the mixture is stirred and mixed to obtain a mixed powder;

[0025] (4) mixing the grinding wheel bond obtained in step (2) and the mixed powder obtained in step (3), heating and stirring at 50 to 75° C. for 1 to 4 hours to obtain a grinding wheel mixture;

[0026] (5) pouring the grinding wheel mixture into a grinding wheel block mold, curing and demoulding to obtain a grinding wheel block;

[0027] (6) The grinding wheel block is bonded to the grinding wheel base to obtain a ceramic resin composite grinding wheel.

[0028] Preferably, in step (2), the carbon fiber and the resin binder in the formulated amounts are mixed, and then heated and stirred in a water bath at 50 to 75° C. for 5 to 120 minutes to obtain a grinding wheel binder.

[0029] Preferably, in step (5), the grinding wheel mixture is poured into a grinding wheel block mold, solidified at 25-180° C., and demoulded to obtain a grinding wheel block.

[0030] Preferably, the dressing method of the ceramic resin composite grinding wheel comprises the following grinding wheel dressing steps:

[0031] (1) Determine the dressing process according to the degree of passivation of the grinding wheel;

[0032] (2) Adding resin solvent to the grinding wheel dressing pad;

[0033] (3) Using the grinding wheel dressing pad in step (2) to perform surface micro-dissolution dressing on the ceramic resin composite grinding wheel.

[0034] Preferably, the resin dissolving agent is a mixed solution of one or more of ethanol, acetic acid, glycerol, citric acid, hydrochloric acid, sulfuric acid, and hydrogen peroxide.

[0035] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0036] 1. This technical solution can obtain a ceramic resin composite grinding wheel with high strength, high rigidity and high wear resistance. The ceramic resin composite grinding wheel of this technical solution can reduce the surface hardness of the hard and brittle workpiece to be processed through the solid-phase chemical reaction of the active metal powder. Combined with the nano-grinding characteristics of the micro-edge polymer abrasive in the ceramic resin composite grinding wheel, it can effectively increase the theoretical cutting depth of the abrasive grains, realize ductile domain grinding processing of hard and brittle materials under large feed conditions, quickly obtain nano-level smooth surface with smaller processing allowance, and reduce the material loss and processing cost of the processing object.

[0037] 2. The preparation method of the ceramic resin composite grinding wheel provided by the present technical solution adopts the spray granulation method to combine the ceramic binder and the ultrafine abrasive with micro-cutting edges to form spherical ultrafine micro-edge polymer abrasive, which can enhance the fixation of the ultrafine abrasive in the resin bond grinding wheel. At the same time, the micro-cutting edges on the surface of the ultrafine abrasive can realize nano-grinding of hard and brittle materials; by adding active metal powder to react with hard and brittle materials in a solid-phase chemical reaction, the surface hardness of the workpiece is reduced, and chemical-mechanical synergy is produced with the micro-edge polymer abrasive to increase the theoretical cutting depth of the abrasive, thereby realizing high-efficiency, low-damage, and ductile-domain grinding of hard and brittle materials; the strength, wear resistance and service life of the resin bonded grinding wheel are enhanced by carbon fiber reinforcement. At the same time, the low-temperature consolidation characteristics of the carbon fiber resin binder can ensure that the active metal powder maintains excellent solid-phase chemical reaction activity during the preparation process.

[0038] 3. The surface of the ceramic resin composite grinding wheel of the present technical solution can be softened by resin solvents such as acids, alkalis or organic reagents that can dissolve the resin bond. The softened layer can be removed under the action of external force, thereby realizing the dressing of the ceramic resin composite grinding wheel. The softened layer thickness and softening rate are controlled by the type, concentration and contact time of the resin solvent, achieving controllable quantitative removal, and realizing fast and low-loss dressing of the ceramic resin composite grinding wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the preparation process of the ceramic resin composite grinding wheel in Example 1 of the present invention;

[0040] Figure 2 The SEM and EDS images of the micro-edge polymer abrasive prepared using ultrafine diamond powder as abrasive in Example 1;

[0041] Figure 3 This is a schematic diagram of the chemical nano-grinding process based on a ceramic resin composite grinding wheel according to Application Example 1;

[0042] Figure 4 Schematic diagram of the dressing process of the ceramic resin composite grinding wheel prepared in Example 1;

[0043] In the accompanying drawings: 1-ultrafine abrasive; 2-ceramic bond; 3-micro-edge polymer abrasive; 4-active metal powder; 5-mixture of pore former, dispersant and wetting agent; 6-mixed powder; 7-carbon fiber powder; 8-resin bond; 9-grinding wheel mixture; 10-grinding wheel block; 11-ceramic resin composite grinding wheel; 12-solid-phase chemical reaction; 13-corrosion layer; 14-mechanical removal; 15-soft dressing pad; 16-specific solution; 17-softening layer; 18-hard dressing pad. DETAILED DESCRIPTION

[0044] For ease of understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0045] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in this field or the product instructions were used. Raw materials used without manufacturer specified are all commercially available conventional products.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0048] A chemical nano-grinding method based on a ceramic resin composite grinding wheel for grinding hard and brittle material workpieces comprises the following steps:

[0049] S1: The ultrafine abrasive with nano-micro-edges is synthesized into large-particle micro-edge polymer abrasive by spray granulation method;

[0050] S2: Micro-edge polymer abrasive is used as grinding wheel abrasive grains, mixed with active metal powder, grinding wheel bond, dispersant, wetting agent and pore-forming agent to prepare a ceramic resin composite grinding wheel;

[0051] S3: Chemical nano-grinding of hard and brittle material workpieces using a ceramic resin composite grinding wheel;

[0052] S4: Dressing the dull grinding wheel with a dressing pad adsorbed with resin solvent.

[0053] This technical solution uses a spray granulation method to combine a ceramic binder and an ultrafine abrasive with a micro-cutting edge to form a spherical ultrafine fine-edge polymer abrasive, which can enhance the fixation of the ultrafine abrasive in the resin-bonded grinding wheel. At the same time, the micro-cutting edge on the surface of the ultrafine abrasive can realize nano-grinding of hard and brittle materials. By adding active metal powder to react with the hard and brittle material in a solid-phase chemical reaction, the surface hardness of the workpiece is reduced, and a chemical-mechanical synergistic effect is produced with the ultrafine fine-edge polymer abrasive to reduce the theoretical cutting depth of the abrasive particles, thereby realizing high-efficiency, low-damage, and ductile-domain grinding of hard and brittle materials. The strength, wear resistance, and service life of the resin-bonded grinding wheel are enhanced by carbon fiber. At the same time, the low-temperature consolidation characteristics of the carbon fiber resin binder can ensure that the active metal powder maintains excellent solid-phase chemical reaction activity during the preparation process.

[0054] The ceramic resin composite grinding wheel of the present technical solution includes a grinding wheel base and a grinding wheel block arranged on the grinding wheel base. The grinding wheel block includes the following raw materials in parts by weight: 30-70 parts of micro-edge polymer abrasive, 20-50 parts of active metal powder, 5-20 parts of grinding wheel bond, 1-10 parts of pore former, 1-5 parts of dispersant and 1-5 parts of wetting agent;

[0055] The micro-edge polymer abrasive comprises the following raw materials in parts by weight: 30 to 50 parts of ultrafine abrasive and 50 to 70 parts of vitrified binder;

[0056] The particle size of the micro-edge polymer abrasive is 20 to 40 μm;

[0057] The grinding wheel bond comprises carbon fiber and resin bond.

[0058] It is worth noting that, through prescription design, this technical solution can obtain a ceramic resin composite grinding wheel with high strength, high rigidity and high wear resistance. The ceramic resin composite grinding wheel of this technical solution can reduce the surface hardness of the hard and brittle workpiece to be processed through the solid-phase chemical reaction of the active metal powder. Combined with the nano-grinding characteristics of the micro-blade polymer abrasive in the ceramic resin composite grinding wheel, it can effectively increase the theoretical cutting depth of the abrasive particles, realize the ductile domain grinding processing of hard and brittle materials under large feed conditions, quickly obtain nano-level smooth surface with smaller processing allowance, and reduce the material loss and processing cost of the processing object.

[0059] It is further explained that the combination of ultrafine abrasives and ceramic binders can form ultrafine micro-blade polymer abrasives with a diameter of 20 to 40 microns. The micro-blade polymer abrasives, carbon fibers and active metals are mixed and formed in a resin binder, thereby maintaining the activity of the active metal and preventing the active metal from oxidizing at high temperatures. The carbon fibers can enhance the structural strength of the resin binder. During high-speed scratching, the active metal can undergo chemical friction with materials such as single-crystal SiC to form a corrosion layer, which can effectively reduce the cutting depth of single-particle abrasives, thereby making it easier for the micro-blade polymer abrasive to achieve ductile domain nano-grinding.

[0060] The ceramic resin composite grinding wheel of the present invention adds active metal powder to the grinding wheel block. During grinding, the active metal powder can undergo a solid-phase chemical reaction with the hard and brittle workpiece to be processed, reducing the surface hardness of the workpiece. At the same time, the active metal powder and the micro-blade polymer abrasive produce a chemical-mechanical synergistic effect, which can increase the theoretical cutting depth of the abrasive particles and achieve high-efficiency, low-damage, ductile-domain grinding of the hard and brittle workpiece to be processed. In addition, this technical solution can significantly enhance the strength, wear resistance and service life of the ceramic resin composite grinding wheel through carbon fiber. At the same time, the grinding wheel bond of this technical solution has low-temperature consolidation characteristics. The low-temperature consolidation characteristics can ensure that the active metal powder maintains excellent solid-phase chemical reaction activity during the grinding wheel preparation process.

[0061] It should be pointed out that the surface of the ceramic resin composite grinding wheel of the present technical solution can be softened by a softening solution such as an acid, alkali or organic reagent (i.e., a resin dissolving agent) that can dissolve the resin binder. The softened layer obtained after softening can be removed under mechanical action, thereby realizing rapid dressing of the ceramic resin composite grinding wheel.

[0062] Preferably, the ceramic resin composite grinding wheel of the present technical solution is used for grinding workpieces made of hard and brittle materials, including single crystal silicon, sapphire, carbide, gallium nitride and diamond.

[0063] Preferably, the ceramic bond is an Al2O3-SiO2-B2O3-Na2O ceramic bond.

[0064] Specifically, the pore-forming agent, dispersant and wetting agent of the present technical solution are well-known, and the pore-forming agent, dispersant and wetting agent commonly used in the field of grinding wheel preparation can be used.

[0065] Preferably, the pore-forming agent is any one of hollow glass balls, plastic balls, and hollow ceramic balls;

[0066] Preferably, the dispersant is any one of sodium lauryl sulfate, polyethylene glycol, and oleic acid;

[0067] Preferably, the wetting agent is any one of paraffin and phenolic resin.

[0068] Further explanation, the ultrafine abrasive includes any one or more combinations of diamond, silicon carbide, aluminum oxide and boron carbide;

[0069] The particle size of the ultrafine abrasive is 0.1-5 μm.

[0070] It is worth noting that the ultrafine abrasives of this technical solution include any one or more combinations of diamond, silicon carbide, aluminum oxide and boron carbide with a particle size of 0.1 to 5 μm. The selection of these ultrafine abrasives can enhance the grinding efficiency and grinding quality of the grinding wheel and realize nano-grinding of hard and brittle materials.

[0071] More preferably, the particle size of the ultrafine abrasive is 0.5-3 μm.

[0072] Further explanation, the active metal powder includes any one or more combinations of iron powder, aluminum powder, chromium powder, titanium powder, cobalt powder, nickel powder and zinc powder;

[0073] The particle size of the active metal powder is 0.5 to 3 μm.

[0074] Specifically, active metal powders such as iron powder, aluminum powder, chromium powder, titanium powder, cobalt powder, nickel powder and zinc powder are conducive to obtaining high-efficiency solid-phase chemical reactions. Active metal powders such as iron powder, aluminum powder, chromium powder, titanium powder, cobalt powder, nickel powder and zinc powder can undergo solid-phase chemical reactions with the surface of the hard and brittle workpiece to be processed, oxidizing the workpiece surface material to form a corrosion layer with lower hardness. The formation of the corrosion layer can reduce the difficulty of grinding processing and is conducive to achieving greater abrasive cutting depth processing, that is, achieving ductile domain processing. At the same time, the particle size of the active metal powder of the present technical solution is 0.5 to 3 μm. By selecting active metal powder with a smaller particle size, the reactivity of the active metal powder can be increased, making it easier for the active metal powder to react with the hard and brittle workpiece to be processed.

[0075] Further explanation, calculated by mass, the grinding wheel binder includes 50 to 75 parts of carbon fiber and 25 to 50 parts of resin binder;

[0076] The carbon fiber has a diameter of 5 to 10 μm and a length of 20 to 200 μm.

[0077] Specifically, this technical solution selects carbon fibers with a diameter of 5 to 10 μm and a length of 20 to 200 μm. At the same time, the carbon fibers have a certain arrangement direction in the grinding wheel binder, which is one of 0°, 45°, and 90°. By arranging the carbon fibers in a directional manner, the strength, stiffness, and wear resistance of the ceramic resin composite grinding wheel can be further improved.

[0078] Further explanation: the resin binder is any one of phenolic resin, epoxy resin and polyimide resin.

[0079] A method for preparing a ceramic resin composite grinding wheel, for preparing the above-mentioned ceramic resin composite grinding wheel, comprises the following steps:

[0080] (1) uniformly mixing the formulated ultrafine abrasive and the ceramic binder, smelting them at 800-1200° C. in an inert gas environment, and then spray granulating them to obtain a micro-edge polymer abrasive;

[0081] (2) mixing the carbon fiber and the resin binder and heating and stirring them in a water bath to obtain a grinding wheel binder;

[0082] (3) After uniformly mixing the micro-edge polymer abrasive and active metal powder in the formula amount, a dispersant, a wetting agent and a pore-forming agent are added, and the mixture is stirred and mixed to obtain a mixed powder;

[0083] (4) mixing the grinding wheel bond obtained in step (2) and the mixed powder obtained in step (3), heating and stirring at 50 to 75° C. for 1 to 4 hours to obtain a grinding wheel mixture;

[0084] (5) pouring the grinding wheel mixture into a grinding wheel block mold, curing and demoulding to obtain a grinding wheel block;

[0085] (6) The grinding wheel block is bonded to the grinding wheel base to obtain a ceramic resin composite grinding wheel.

[0086] It is worth noting that in step (1), the ceramic binder and the ultrafine abrasive with micro-cutting edges are combined by the spray granulation method to form a spherical micro-edge polymer abrasive, which can enhance the fixation of the ultrafine abrasive in the grinding wheel. At the same time, the micro-cutting edges on the surface of the ultrafine abrasive can realize nano-grinding of hard and brittle materials.

[0087] Specifically, in step (3), the micro-edge polymer abrasive and active metal powder are mixed uniformly, and then a dispersant, a wetting agent and a pore-forming agent are added in sequence, and mechanical stirring is performed for 5-120 minutes to obtain a mixed powder;

[0088] In step (6), epoxy resin can be used to bond the grinding wheel block to the grinding wheel matrix to obtain a ceramic resin composite grinding wheel.

[0089] Further explanation: in step (2), the carbon fiber and the resin binder in the formulated amount are mixed, and then heated and stirred in a water bath at 50 to 75° C. for 5 to 120 minutes to obtain a grinding wheel binder.

[0090] Further explanation: in step (5), the grinding wheel mixture is poured into a grinding wheel block mold, solidified at 25-180° C., and demoulded to obtain a grinding wheel block.

[0091] A method for grinding a hard and brittle workpiece using the ceramic resin composite grinding wheel comprises the following steps:

[0092] Determine the machining process parameters (such as grinding wheel speed, feed rate and total feed rate) based on the initial surface topography and machining requirements of the hard and brittle workpiece to be machined;

[0093] The ceramic resin composite grinding wheel is used to grind hard and brittle workpieces to be processed.

[0094] It is worth noting that the ceramic resin composite grinding wheel of this technical solution is used to grind hard and brittle workpieces, which can provide a new chemical nano-grinding technology. The surface hardness of the hard and brittle workpiece to be processed can be reduced through the solid-phase chemical reaction of the active metal powder. Combined with the nano-grinding characteristics of the micro-blade polymer abrasive, the theoretical cutting depth of the abrasive can be effectively improved, and the one-step processing of rough grinding and fine grinding can be achieved, thereby realizing high-efficiency, low-damage, and ductile domain grinding of hard and brittle materials. The disadvantage of using conventional grinding wheels for grinding, which requires frequent replacement and dressing of grinding wheels, is improved, thereby improving the overall processing efficiency.

[0095] Specifically, according to the material properties of the hard and brittle workpiece to be processed, a grinding wheel made of suitable active metal powder and micro-edge polymer abrasive can be selected for grinding, thereby improving the efficiency and quality of the grinding process.

[0096] Specifically, the micro-blade polymer abrasive in the ceramic resin composite grinding wheel mechanically removes the corrosion layer at a lower theoretical cutting depth of the abrasive grains. By changing the processing parameters, the solid-phase chemical reaction rate and the mechanical removal rate are regulated, and a dynamic balance is achieved between the two. This can achieve high-efficiency, low-damage, ductile domain grinding processing, realize one-step rough grinding and fine grinding, improve the disadvantage of the grinding wheel needing to be replaced and dressed, and improve overall processing efficiency.

[0097] To further illustrate, the hard and brittle workpiece to be processed is a workpiece made of a hard and brittle material, and the hard and brittle material includes any one or more combinations of single crystal silicon, sapphire, silicon carbide, gallium nitride and diamond.

[0098] Specifically, single crystal silicon, sapphire, silicon carbide, gallium nitride, and diamond are all hard and brittle materials with high hardness, brittleness, and chemical stability. Grinding workpieces made of these materials using conventional grinding wheels is difficult. The ceramic-resin composite grinding wheel of this technical solution can perform both rough and fine grinding in one step, achieving high-efficiency, low-damage, and ductile-domain grinding of hard and brittle materials.

[0099] It should be pointed out that the surface of the ceramic resin composite grinding wheel of the present technical solution can be softened by resin dissolving agents such as acids, alkalis or organic reagents that can dissolve the resin binder. The softened layer obtained after softening can be removed under the action of external force, thereby realizing the dressing of the ceramic resin composite grinding wheel. The softening layer thickness and softening rate are controlled by the type, concentration and contact time of the softening solution, achieving controllable quantitative removal, and realizing rapid and low-loss dressing of the ceramic resin composite grinding wheel.

[0100] Specifically, the dressing method of the ceramic resin composite grinding wheel of the present technical solution includes the following steps:

[0101] (1) According to the degree of passivation of the grinding wheel, the dressing process is determined, and a resin solvent is added to the grinding wheel dressing pad; the ceramic resin composite grinding wheel is brought into contact with the dressing pad absorbed with the resin solvent, and the grinding wheel surface softens;

[0102] (2) setting the grinding wheel rotation speed according to the required dressing amount, and regulating the contact time between the grinding wheel and the soft dressing pad that absorbs the softening solution to control the thickness of the single softening layer of the grinding wheel;

[0103] (3) As the grinding wheel rotates, the grinding wheel with a softened surface rotates out of the soft dressing pad and contacts the hard dressing pad that does not contain a softening solution;

[0104] (4) The hard dressing pad removes the softened layer on the surface of the grinding wheel through mechanical action and removes the residual softening solution. This process is repeated over and over again. When the target dressing amount is reached, the grinding wheel is sharpened.

[0105] It should be noted that the resin dissolving agent can be any acid, base or organic reagent that can dissolve the resin binder. As an embodiment of the present invention, the resin dissolving agent is one or more of ethanol, acetic acid, glycerol, citric acid, hydrochloric acid, sulfuric acid and hydrogen peroxide.

[0106] Furthermore, the softening solution can be absorbed and soaked by a soft finishing pad, the soft finishing pad has corrosion and oxidation resistance, and the soft finishing pad can be one of a polyurethane pad, felt or a plush pad.

[0107] Furthermore, the thickness and softening rate of the softening layer are controlled by the type, concentration and contact time of the softening solution. The soft layer formed after the grinding wheel surface is softened can be separated from the unsoftened part and removed under the action of external force.

[0108] Furthermore, the external force may be generated by grinding wheel dressing consumables such as hard dressing pads and grinding wheel dressing oilstones that can produce a mechanical removal effect.

[0109] In a preferred technical solution of the present invention, the dressing method of the ceramic resin composite grinding wheel comprises the following steps:

[0110] (1) The ceramic resin composite grinding wheel is brought into contact with a soft dressing pad that has absorbed citric acid, and the surface of the grinding wheel softens.

[0111] (2) The grinding wheel dressing amount was set to 0.1 mm, the grinding wheel rotation speed was 1000 rpm, and the contact time between the grinding wheel and the soft dressing pad absorbed with citric acid was adjusted to 30 min to control the thickness of the single softening layer of the grinding wheel;

[0112] (3) As the grinding wheel rotates, the grinding wheel with a softened surface rotates out of the soft dressing pad and contacts the hard dressing pad that does not contain citric acid;

[0113] (4) The hard dressing pad removes the softened layer and removes the residual citric acid through mechanical action, and this process is repeated over and over again until the target dressing amount is reached to achieve the grinding wheel dressing and sharpening.

[0114] Example 1

[0115] The ceramic resin composite grinding wheel of this embodiment includes a grinding wheel base and a grinding wheel block arranged on the grinding wheel base. The grinding wheel block includes the following raw materials in parts by mass: 45 parts of micro-edge polymer abrasive, 30 parts of active metal powder (W3 aluminum powder), 15 parts of grinding wheel bond, 3 parts of pore-forming agent (hollow glass spheres), 4 parts of dispersant (sodium lauryl sulfate), and 3 parts of wetting agent (phenolic resin);

[0116] The micro-edge polymer abrasive is composed of the following raw materials by weight: 40 parts of ultrafine abrasive (W0.5 diamond powder) and 60 parts of vitrified bond (Al2O3-SiO2-B2O3-Na2O vitrified bond), where W0.5 diamond powder refers to artificial diamond powder with a particle size of 0.5 μm; the particle size of the micro-edge polymer abrasive is about 25 μm;

[0117] The grinding wheel bond is a mixture of 60 parts of carbon fiber and 40 parts of resin bond (phenolic resin). The diameter of the carbon fiber is 5 μm, the length is 40 μm, and the arrangement direction of the carbon fiber is 90°.

[0118] The preparation method of the ceramic resin composite grinding wheel of the present technical solution comprises the following steps:

[0119] (1) ball-milling the formulated ultrafine abrasive and ceramic binder, mixing them uniformly, smelting them at 1000° C. in a nitrogen environment, and then spray-granulating them using a spray granulation device. After screening, spherical micro-edge polymer abrasives with a particle size of about 25 μm are obtained;

[0120] (2) mixing the carbon fiber and the resin binder in a formulated amount and heating and stirring the mixture in a 50° C. water bath for 90 minutes to obtain a grinding wheel binder;

[0121] (3) After uniformly mixing the micro-edge polymer abrasive and active metal powder in the formula amount, a dispersant, a wetting agent, and a pore-forming agent are added in sequence, and mechanically stirred for 90 minutes to obtain a mixed powder;

[0122] (4) mixing the grinding wheel binder obtained in step (2) and the mixed powder obtained in step (3), heating and stirring at 75° C. for 3 h to obtain a grinding wheel mixture;

[0123] (5) pouring the grinding wheel mixture into a grinding wheel block mold, curing it at room temperature, and obtaining a grinding wheel block after demoulding;

[0124] (6) The grinding wheel block is bonded to the grinding wheel base through epoxy resin to obtain a ceramic resin composite grinding wheel.

[0125] Example 2

[0126] The formulation and preparation method of the vitrified resin composite grinding wheel of this embodiment are essentially the same as those of Example 1, except that the active metal powder of this embodiment is iron powder with a particle size of 1 μm; the ultrafine abrasive in the micro-edge polymer abrasive is W3 diamond powder, i.e., diamond powder with a particle size of 3 μm; and the particle size of the micro-edge polymer abrasive of this embodiment is approximately 35 μm. The vitrified resin composite grinding wheel produced in this embodiment combines a high solid-phase chemical reaction rate with high mechanical removal capacity.

[0127] Example 3

[0128] The formula composition of the ceramic resin composite grinding wheel of this embodiment is basically the same as that of Example 1, except that the active metal powder of this embodiment is aluminum powder with a particle size of 1 μm; the ultrafine abrasive in the micro-blade polymer abrasive is W0.1 diamond powder, that is, diamond powder with a particle size of 0.1 μm; and the particle size of the micro-blade polymer abrasive of this embodiment is approximately 20 microns.

[0129] The preparation method of the ceramic resin composite grinding wheel of the present embodiment comprises the following steps:

[0130] (1) ball-milling the formulated ultrafine abrasive and ceramic binder, mixing them uniformly, smelting them at 1000° C. in a nitrogen environment, and then spray-granulating them using a spray granulation device. After screening, spherical micro-edge polymer abrasives with a particle size of about 20 μm are obtained;

[0131] (2) mixing the carbon fiber and the resin binder in a formulated amount and heating and stirring the mixture in a 50° C. water bath for 120 min to obtain a grinding wheel binder;

[0132] (3) After uniformly mixing the formulated amount of micro-edge polymer abrasive and active metal powder (W1 aluminum powder), dispersant, wetting agent and pore-forming agent were added in sequence, and mechanical stirring was performed for 120 minutes to obtain a mixed powder;

[0133] (4) mixing the grinding wheel binder obtained in step (2) and the mixed powder obtained in step (3), heating and stirring at 75° C. for 4 h to obtain a grinding wheel mixture;

[0134] (5) pouring the grinding wheel mixture into a grinding wheel block mold, curing it at room temperature, and obtaining a grinding wheel block after demoulding;

[0135] (6) The grinding wheel block is bonded to the grinding wheel base through epoxy resin to obtain a ceramic resin composite grinding wheel.

[0136] Example 4

[0137] The formula composition of the ceramic resin composite grinding wheel of this embodiment is basically the same as that of Example 1, except that the active metal powder W3 zinc powder of this embodiment is zinc powder with a particle size of 3 μm; and the particle size of the micro-blade polymer abrasive of this embodiment is about 25 microns.

[0138] The preparation method of the ceramic resin composite grinding wheel of the present embodiment comprises the following steps:

[0139] (1) ball-milling the formulated ultrafine abrasive and ceramic binder, mixing them uniformly, smelting them at 800° C. in a nitrogen environment, and then spray-granulating them using a spray granulation device. After screening, spherical micro-edge polymer abrasives with a particle size of about 25 μm are obtained;

[0140] (2) mixing the carbon fiber and the resin binder in a formulated amount and heating and stirring the mixture in a 50° C. water bath for 90 minutes to obtain a grinding wheel binder;

[0141] (3) After uniformly mixing the formulated amount of micro-edge polymer abrasive and active metal powder (W3 zinc powder), dispersant, wetting agent and pore-forming agent were added in sequence, and mechanical stirring was performed for 90 minutes to obtain a mixed powder;

[0142] (4) mixing the grinding wheel binder obtained in step (2) and the mixed powder obtained in step (3), heating and stirring at 75° C. for 3 h to obtain a grinding wheel mixture;

[0143] (5) pouring the grinding wheel mixture into a grinding wheel block mold, curing it at room temperature, and obtaining a grinding wheel block after demoulding;

[0144] (6) The grinding wheel block is bonded to the grinding wheel base through epoxy resin to obtain a ceramic resin composite grinding wheel.

[0145] Application Example 1

[0146] A chemical nano-grinding method based on a ceramic resin composite grinding wheel is used for grinding a single-crystal SiC workpiece, wherein the initial roughness of the single-crystal SiC workpiece is about 100 nm, and the surface roughness after grinding is required to be about 4 nm. Based on the material properties of the single-crystal SiC workpiece, the ceramic resin composite grinding wheel prepared in Example 1 is used for grinding, comprising the following steps:

[0147] S1: According to the initial surface morphology and processing requirements of the single crystal SiC workpiece to be processed, the processing parameters are determined as follows: the grinding wheel speed is 1400 rpm, the feed rate is 0.1 μm / s, and the total feed amount is 50 μm;

[0148] S2: Using the ceramic resin composite grinding wheel of Example 1 to perform chemical nano-grinding on the single-crystal SiC workpiece to be machined, the aluminum powder in the ceramic resin composite grinding wheel reacts with the SiC in a solid-phase chemical reaction, corroding and oxidizing the high-hardness SiC surface into SiO2, thereby forming a corrosion layer on the surface of the workpiece, reducing the surface hardness of the workpiece;

[0149] S3: The micro-edge polymer abrasive in the ceramic resin composite grinding wheel mechanically removes the corrosion layer at a lower theoretical cutting depth of the abrasive grains to complete the grinding process.

[0150] Application Example 2

[0151] This application embodiment is based on a chemical nano-grinding method using a ceramic resin composite grinding wheel, and is used to grind a single crystal diamond sheet. The initial surface roughness of the single crystal diamond sheet is 50 nm, and the surface roughness after grinding is required to be about 3 nm. The single crystal diamond sheet has high hardness and high chemical stability, and the grinding wheel needs to have both a high solid-phase chemical reaction rate and a high mechanical removal ability. Therefore, the ceramic resin composite grinding wheel prepared in Example 2 is used for grinding. The active metal powder of the ceramic resin composite grinding wheel in Example 2 is W1 iron powder. W1 iron powder has a higher solid-phase chemical reaction activity with single crystal diamond, and the ceramic resin composite grinding wheel prepared with W3 diamond powder of a larger particle size has a higher mechanical removal ability. The method for chemical nano-grinding of a single crystal diamond sheet in this application embodiment includes the following steps:

[0152] S1: According to the initial surface morphology of the single crystal diamond sheet to be processed and the processing requirements, the processing parameters are determined as follows: the grinding wheel speed is 2400 rpm, the feed rate is 0.1 μm / s, and the total feed amount is 40 μm;

[0153] S2: Grinding the single-crystal SiC workpiece using the ceramic resin composite grinding wheel of Example 2. The iron powder in the ceramic resin composite grinding wheel reacts with the diamond in a solid phase, corroding and oxidizing the surface of the high-hardness single-crystal diamond sheet to form a corrosion layer, thereby reducing the surface hardness of the workpiece.

[0154] S3: The micro-edge polymer abrasive in the ceramic resin composite grinding wheel mechanically removes the corrosion layer at a lower theoretical cutting depth of the abrasive grains to complete the grinding process.

[0155] Application Example 3

[0156] This application embodiment is based on a chemical nano-grinding method using a ceramic resin composite grinding wheel, and is used to grind a single-crystal SiC workpiece. The initial surface roughness of the single-crystal SiC workpiece in this application embodiment is 50 nm, and the surface roughness after grinding is required to be approximately 2 nm. The ceramic resin composite grinding wheel prepared in Example 3 is selected for grinding. The ceramic resin composite grinding wheel prepared in Example 3 uses W1 aluminum powder with a smaller particle size that has higher solid-phase chemical reaction activity with single-crystal SiC as the active metal powder, and W0.1 diamond powder with a smaller particle size is used to prepare a micro-blade polymer abrasive.

[0157] This application embodiment is based on a chemical nano-grinding method of a ceramic resin composite grinding wheel, comprising the following steps:

[0158] S1: According to the initial surface morphology and processing requirements of the single crystal SiC workpiece to be processed, the processing parameters are determined as follows: the grinding wheel speed is 2000 rpm, the feed rate is 0.05 μm / s, and the total feed amount is 50 μm;

[0159] S2: The ceramic resin composite grinding wheel of Example 3 is used to grind the single crystal SiC workpiece to be processed. The aluminum powder in the ceramic resin composite grinding wheel reacts with the SiC in a solid phase chemical reaction, corroding and oxidizing the SiC surface into SiO2, forming a corrosion layer, and reducing the surface hardness of the workpiece;

[0160] S3: The micro-edge polymer abrasive in the ceramic resin composite grinding wheel mechanically removes the corrosion layer at a lower theoretical cutting depth of the abrasive grains. By regulating the solid-phase chemical reaction rate in step S2 and the mechanical removal rate in step S3, a dynamic balance is achieved to achieve high-efficiency, low-damage, ductile-domain grinding of single-crystal SiC.

[0161] Application Example 4

[0162] This application embodiment is based on a chemical nano-grinding method using a ceramic resin composite grinding wheel, and is used to grind a single-crystal GaN workpiece. The initial surface roughness of the single-crystal GaN workpiece in this application embodiment is 50 nm, and the surface roughness after grinding is required to be approximately 5 nm. The ceramic resin composite grinding wheel prepared in Example 4 is selected for grinding. The ceramic resin composite grinding wheel prepared in Example 4 uses W3 zinc powder, which has higher solid-phase chemical reaction activity with single-crystal GaN, as the active metal powder.

[0163] This application embodiment is based on a chemical nano-grinding method of a ceramic resin composite grinding wheel, comprising the following steps:

[0164] S1: Based on the initial surface morphology and machining requirements of the single-crystal SiC workpiece to be machined, the machining process parameters are determined as follows: grinding wheel speed of 1400 rpm, feed rate of 0.15 μm / s, and total feed of 50 μm. Since GaN has a lower hardness than SiC and diamond abrasives, a faster feed rate is used to improve grinding efficiency.

[0165] S2: The ceramic resin composite grinding wheel of Example 4 is used to grind the single crystal GaN workpiece to be machined. The W3 zinc powder in the ceramic resin composite grinding wheel reacts with the GaN in a solid phase chemical reaction, corroding and oxidizing the GaN surface into Ga2O3, forming a corrosion layer, and reducing the surface hardness of the workpiece;

[0166] S3: The micro-edge polymer abrasive in the ceramic resin composite grinding wheel mechanically removes the corrosion layer at a lower theoretical cutting depth of the abrasive grains;

[0167] S4: By regulating the solid-phase chemical reaction rate of step S2 and the mechanical removal rate of step S3 to achieve a dynamic balance, high-efficiency, low-damage, ductile-domain grinding of single-crystal SiC is achieved.

[0168] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A chemical nano-grinding method based on a ceramic resin composite grinding wheel for grinding hard and brittle material workpieces, characterized in that: The following steps are involved: S1: The ultrafine abrasive with nano-micro-edges is synthesized into large-particle micro-edge polymer abrasive by spray granulation method; S2: Micro-edge polymer abrasive is used as grinding wheel abrasive grains, mixed with active metal powder, grinding wheel bond, dispersant, wetting agent and pore-forming agent to prepare a ceramic resin composite grinding wheel; S3: Chemical nano-grinding of hard and brittle material workpieces using a ceramic resin composite grinding wheel; S4: Dressing the passivated grinding wheel using a dressing pad adsorbed with a resin solvent; in, The ceramic resin composite grinding wheel comprises the following raw materials in parts by mass: 30-70 parts of micro-edge polymer abrasive, 20-50 parts of active metal powder, 5-20 parts of grinding wheel bond, 1-10 parts of pore former, 1-5 parts of dispersant and 1-5 parts of wetting agent; The preparation method of the ceramic resin composite grinding wheel comprises the following steps: (1) The ultrafine abrasive and the ceramic binder are mixed uniformly, smelted in an inert gas environment at 800-1200°C, and then spray granulated to obtain a micro-edge polymer abrasive; (2) The carbon fiber and resin binder are mixed and heated and stirred in a water bath to obtain a grinding wheel binder; (3) Add the formulated amount of micro-edge polymer abrasive and active metal pink After the powder is evenly mixed, dispersant, wetting agent and pore-forming agent are added, and stirred and mixed to obtain mixed powder; (4) mixing the grinding wheel binder obtained in step (2) and the mixed powder obtained in step (3), heating and stirring at 50-75° C. for 1-4 h to obtain a grinding wheel mixture; (5) Pour the grinding wheel mixture into the grinding wheel block mold, solidify and demould to obtain the grinding wheel block; (6) The grinding wheel block is bonded to the grinding wheel base to obtain a ceramic resin composite grinding wheel.

2. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 1, characterized in that: The micro-edge polymer abrasive comprises the following raw materials in parts by weight: 30-50 parts of ultrafine abrasive and 50-70 parts of vitrified binder; the particle size of the micro-edge polymer abrasive is 20-40 μm; The ultrafine abrasive includes any one or more combinations of diamond, silicon carbide, aluminum oxide and boron carbide; the particle size of the ultrafine abrasive is 0.1-5 μm.

3. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 1, characterized in that: The active metal powder includes any one or more combinations of iron powder, aluminum powder, chromium powder, titanium powder, cobalt powder, nickel powder and zinc powder; the particle size of the active metal powder is 0.5-3 μm.

4. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 1, characterized in that: The grinding wheel bond comprises the following raw materials in parts by mass: 50-75 parts of carbon fiber and 25-50 parts of resin bond; the carbon fiber has a diameter of 5-10 μm and a length of 20-200 μm; The resin binder is any one of phenolic resin, epoxy resin and polyimide resin.

5. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 1, characterized in that: In step (2), the carbon fiber and the resin binder in the formulated amount are mixed, and then heated and stirred in a water bath at 50-75° C. for 5-120 min to obtain a grinding wheel binder.

6. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 1, characterized in that: In step (5), the grinding wheel mixture is poured into a grinding wheel block mold, solidified at 25-180° C., and demolded to obtain a grinding wheel block.

7. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 1, characterized in that: Step S4 uses a dressing pad adsorbed with a resin dissolving agent to dress the passivated grinding wheel, including the following dressing steps: (1) Determine the dressing process according to the degree of passivation of the grinding wheel; (2) Adding resin solvent to the grinding wheel dressing pad; (3) Using the grinding wheel dressing pad of step (2), the surface of the ceramic resin composite grinding wheel is slightly dissolved and dressed.

8. The chemical nano-grinding method based on a ceramic resin composite grinding wheel according to claim 7, characterized in that: The resin dissolving agent is a mixed solution of one or more of ethanol, acetic acid, glycerol, citric acid, hydrochloric acid, sulfuric acid and hydrogen peroxide.

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