Resin grinding wheel and preparation method thereof

Abstract

The invention relates to a resin grinding wheel and a preparation method thereof. During preparation of the resin grinding wheel, micro-powder grinding materials are combined into a material block through a ceramic bond, 8-10% of organic solvent is used for separating the material block, sintering is conducted through a sintering method, the organic solvent is volatilized, the ceramic bond and the micro-powder grinding materials are fully bonded, and a submicrostructure grinding material block is obtained. Due to the fact that the resin grinding wheel is provided with the submicrostructure abrasive material balls, each material ball is composed of a plurality of abrasives with smaller particle sizes, the resin grinding wheel is provided with more cutting edges, chip removal is not prone to blockage, and long-acting self-sharpening can be achieved by combining overheating self-sharpening of the resin grinding wheel and breaking self-sharpening of a ceramic bond. The resin grinding wheel is compatible with hard alloy, ceramic coating and high-speed steel micro drill machining, and adapts to dry type and wet type grinding environments.

Description

Technical Field

[0001] The present application belongs to the technical field of composite grinding wheels, and in particular relates to resin grinding wheels and a preparation method thereof. Background Art

[0002] Microdrills (diameter ≤1mm) are widely used in fields such as PCB drilling and microelectronics packaging. They are often made of cemented carbide (such as WC-Co) or tungsten steel (such as high-density tungsten alloy). These materials offer high hardness (HRA ≥90), high wear resistance, and impact resistance, but they also place extremely high demands on the machining tools. The machining accuracy of the microdrill chip flute directly impacts drilling quality and tool life. Key requirements include micron-level control of flute depth and width, a smooth and fluid flute profile to optimize chip removal efficiency, and long-term stability of the grinding wheel at high grinding speeds (≥20,000 rpm).

[0003] However, traditional grinding wheel technology has significant defects when processing superhard materials such as cemented carbide and tungsten steel:

[0004] Abrasives are passivated quickly: Ordinary abrasives (such as CBN and diamond) are easily passivated when processing high-hardness materials, requiring frequent dressing (dressing is required every 50 to 80 pieces), resulting in low efficiency;

[0005] Poor thermal stability: The resin bond has a low heat resistance threshold (≤150°C) and is prone to softening and deformation during high-speed grinding, resulting in groove accuracy deviation (tolerance ±3μm to 5μm) and increased surface roughness.

[0006] Traditional vitrified bond grinding wheels have significant defects:

[0007] Insufficient self-sharpening: The vitrified bond is hard and brittle, and the abrasive particles cannot fall off automatically after being passivated, resulting in increased grinding force and worsened surface roughness.

[0008] Risk of brittle fracture: When machining tungsten carbide, the hardness of the grinding wheel and the workpiece is overmatched, which can easily cause the abrasive or matrix to fracture, resulting in defects in the groove edge.

[0009] Traditional ceramic-resin composite grinding wheels cannot solve the problems of resin phase failure and interface stress concentration at high temperatures, and are difficult to meet the ultra-precision machining requirements of cemented carbide and tungsten steel micro-drills. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a resin grinding wheel and a preparation method thereof in order to solve one of the shortcomings of the conventional grinding wheel technology in the prior art when processing micro-drill chip grooves.

[0011] The technical solution adopted by the present invention to solve its technical problem is:

[0012] A method for preparing a resin grinding wheel comprises the following steps:

[0013] S1, abrasive is prepared by mixing 8% to 12% of vitrified binder, 75% to 90% of micro-powder abrasive, 0% to 5% of filler, and 8% to 10% of organic solvent;

[0014] S2, sintering to bond the ceramic binder and the micro-powder abrasive to form a submicrostructured abrasive mass;

[0015] S3, cooling and cleaning the submicrostructure abrasive material mass;

[0016] S4, mixing 89% to 91% of the submicrostructured abrasive material mass obtained in S3, 7.5% to 8.5% of a resin binder, and 1.5% to 2.5% of a filler, and filling the mixture into a mold for pre-pressing to form a grinding wheel blank;

[0017] S5, dressing the working surface of the grinding wheel blank.

[0018] Preferably, in the method for preparing the resin grinding wheel of the present invention, in step S2, the sintering temperature is 900°C to 1200°C.

[0019] Preferably, in the method for preparing the resin grinding wheel of the present invention, in step S4, the step of filling the mold into a pre-pressing molding step is: hot pressing and curing at 180° C. and 15 MPa for 2 hours.

[0020] Preferably, in the method for preparing the resin grinding wheel of the present invention, the micro-powder abrasive is one or more of cubic boron nitride abrasive, microcrystalline ceramic corundum abrasive, and green silicon carbide abrasive.

[0021] Preferably, in the method for preparing the resin grinding wheel of the present invention, in step S5, the working surface of the grinding wheel blank is sharpened by laser.

[0022] Preferably, in the method for preparing the resin grinding wheel of the present invention, the filler used in step S4 includes silicon carbide filler.

[0023] Preferably, in the method for preparing the resin grinding wheel of the present invention, in step S3, after cleaning the submicrostructure abrasive agglomerates, the submicrostructure abrasive agglomerates having a particle size of 5 μm to 20 μm are screened out.

[0024] Preferably, in the method for preparing a resin grinding wheel of the present invention, in step S4, the resin binder is a phenolic resin binder.

[0025] The present invention provides a resin grinding wheel, comprising:

[0026] The surface layer is formed by bonding a plurality of submicrostructured abrasive material groups with a resin binder; the submicrostructured abrasive material groups are formed by bonding a plurality of micro-powder abrasives with a ceramic binder;

[0027] The inner layer includes the filler.

[0028] The present invention provides a resin grinding wheel, which is prepared by the above-mentioned preparation method of the resin grinding wheel.

[0029] The beneficial effects of the present invention are as follows: in step S1, the micro-powder abrasive is combined into a mass by a vitrified bond, wherein 8% to 10% of an organic solvent is used to separate the mass; in step S2, the organic solvent is volatilized by sintering to fully bond the vitrified bond to the micro-powder abrasive to obtain a submicrostructured abrasive mass; then, after cooling and cleaning the mass in step S3, the resin bond and filler are mixed to obtain a grinding wheel blank; and finally, the resin grinding wheel is trimmed to obtain a finished resin grinding wheel. Since the resin grinding wheel has a submicrostructured abrasive mass, a single mass is composed of multiple smaller particle size abrasives, has more cutting edges, and chip removal is not easily blocked. The resin grinding wheel can combine the overheating self-sharpening of the resin grinding wheel with the crushing self-sharpening of the vitrified bond to achieve long-term self-sharpening. In the resin grinding wheel of the present invention, the resin bond has toughness, can absorb grinding vibration, and reduce the edge collapse rate of the carbide micro-drill. The submicrostructured abrasive mass is synthesized by mixing ceramic bond and micro-powder abrasive. Its dense structure can withstand the severe grinding load of high-hardness materials, and can effectively reduce the abrasive passivation rate compared to single particles. Each submicrostructured abrasive mass acts as an independent heat conduction unit, quickly conducting heat from the grinding area to the resin network, avoiding local temperature rise exceeding the resin heat resistance threshold (≤180°C), thereby inhibiting the softening and deformation of the bond. Therefore, the resin grinding wheel of the present invention is compatible with carbide, ceramic coating, and high-speed steel micro-drilling processing, and is adaptable to dry and wet grinding environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The technical solution of the present application is further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 Schematic diagram of the abrasive structure obtained by mixing in step S1 of the resin grinding wheel preparation method of the present application embodiment;

[0032] Figure 2 Schematic diagram of the structure of the submicrostructured abrasive mass obtained by sintering in step S2 of the resin grinding wheel preparation method according to an embodiment of the present application;

[0033] Figure 3 This is a schematic diagram of the microstructure of the grinding wheel blank obtained in step S4 of the resin grinding wheel preparation method of an embodiment of the present application.

[0034] The reference numerals in the figures are:

[0035] 1. Ceramic binder; 2. Micro-powder abrasive; 3. Organic solvent; 4. Submicrostructured abrasive agglomerate; 5. Resin binder; 6. Filler. DETAILED DESCRIPTION

[0036] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0039] In this embodiment, the percentages of components provided are by weight unless otherwise specified.

[0040] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0041] This embodiment provides a method for preparing a resin grinding wheel, comprising the following steps:

[0042] S1, such as Figure 1 As shown, 8% to 12% of ceramic binder 1, 75% to 90% of micro-powder abrasive 2, 0% to 5% of filler ( Figure 1 The figure shows the case of 0% filler), 8% to 10% organic solvent 3 is mixed to prepare the abrasive;

[0043] S2, sintering by sintering method to bond the ceramic binder 1 and the micro-powder abrasive 2 into a shape, such as Figure 2 As shown, a submicrostructured abrasive mass 4 is formed;

[0044] S3, cooling and cleaning the submicrostructure abrasive material mass 4;

[0045] S4, after mixing 89% to 91% of the submicrostructure abrasive material mass 4 obtained in S3, 7.5% to 8.5% of the resin binder 5 and 1.5% to 2.5% of the filler 6, fill it into a mold for pre-pressing to form a grinding wheel blank. The microstructure of the grinding wheel blank is as follows: Figure 3 As shown;

[0046] S5, dressing the working surface of the grinding wheel blank.

[0047] The resin grinding wheel preparation method provided in this embodiment comprises the following steps: in step S1, the micro-powder abrasive 2 is combined into a mass by a vitrified binder 1, wherein 8% to 10% of an organic solvent 3 is used to separate the mass; in step S2, the vitrified binder 1 is sintered to volatilize the organic solvent, thereby fully bonding the micro-powder abrasive 2 to the vitrified binder 1. Figure 2 As shown, a submicrostructure abrasive mass 4 is obtained, and then after cooling and cleaning the mass in step S3, a resin binder 5 and a filler 6 are mixed to prepare a grinding wheel blank, and finally a resin grinding wheel is sharpened. Because the resin grinding wheel has a submicrostructure abrasive mass 4, a single mass is composed of a plurality of smaller particle size abrasives, has more cutting edges, and the chip removal is not easily blocked. It can combine the overheating self-sharpening of the resin grinding wheel and the crushing self-sharpening of the ceramic binder to achieve long-term self-sharpening. In the resin grinding wheel of this embodiment, the resin binder 5 has toughness, wraps the submicrostructure abrasive mass 4 to form a three-dimensional elastic support layer, can absorb grinding vibration, and reduce the edge collapse rate of the cemented carbide micro-drill. The submicrostructure abrasive mass 4 is synthesized by mixing the ceramic binder 1 and the micro-powder abrasive 2. Its dense structure can withstand the severe grinding load of high-hardness materials and can effectively reduce the abrasive passivation rate compared to single particles. Each submicrostructured abrasive mass 4 acts as an independent heat transfer unit, rapidly transferring heat from the grinding zone to the resin network, preventing local temperature rise from exceeding the resin's heat resistance threshold (≤180°C), thereby inhibiting softening and deformation of the bond. Therefore, the resin grinding wheel of this embodiment is compatible with micro-drilling of cemented carbide, ceramic coatings, and high-speed steel, and is suitable for both dry and wet grinding environments.

[0048] Preferably, in the method for preparing the resin grinding wheel of this embodiment, in step S2, the sintering temperature is 900°C, 1000°C, 1100°C, or 1200°C, or can be another temperature between 900°C and 1200°C. At this temperature setting, the vitrified bond 1 and the micro-powder abrasive 2 can be fully bonded and formed, while the organic solvent 3 can be fully volatilized to facilitate subsequent cleaning.

[0049] Preferably, in the preparation method of the resin grinding wheel of this embodiment, in step S4, the step of filling the mold into the pre-pressing molding step is: hot pressing and curing for 2 hours under the conditions of 180° C. and 15 MPa to ensure that the grinding wheel blank has a dense structure.

[0050] Preferably, in the preparation method of the resin grinding wheel of this embodiment, the micro-powder abrasive 2 is one or more of cubic boron nitride abrasive, microcrystalline ceramic corundum abrasive, and green silicon carbide abrasive, which has a relatively high hardness so that the sub-microstructure abrasive mass 4 can withstand the severe grinding load of high-hardness materials.

[0051] Preferably, in the method for preparing the resin grinding wheel of this embodiment, in step S5, the working surface of the grinding wheel blank is sharpened by laser, which is beneficial to ensuring the accuracy of the processed groove profile, for example, ensuring that the error of the processed groove profile is ≤2μm.

[0052] Preferably, in the method for preparing the resin grinding wheel of this embodiment, the filler used in step S4 includes silicon carbide filler. Silicon carbide filler can enhance the rigidity of the resin grinding wheel, resist high-frequency impact loads during tungsten steel processing, and prevent cracking of the matrix.

[0053] Preferably, in the method for preparing the resin grinding wheel of this embodiment, in step S3, after cleaning the submicrostructured abrasive agglomerates 4, the submicrostructured abrasive agglomerates 4 having a particle size of 5 μm to 20 μm are screened to stabilize the grinding loss and workpiece removal of the resin grinding wheel. The submicrostructured abrasive agglomerates 4 can be manually produced and screened, and their particle size is more uniform than that of single-particle abrasives at the same particle size, making the maximum and minimum deviations of the particle size easier to control.

[0054] The screening method can be to use a 5μm pore size screen to screen out the submicrostructure abrasive agglomerates 4 with a particle size below 5μm, and then use a 20μm pore size screen to screen out the submicrostructure abrasive agglomerates 4 with a particle size above 20μm, and retain the submicrostructure abrasive agglomerates 4 of 5μm to 20μm.

[0055] Preferably, in the method for preparing the resin grinding wheel of this embodiment, in step S4, the resin binder 5 is a phenolic resin binder. The benzene ring structure of the phenolic resin binder gives it excellent high-temperature resistance, with a long-term operating temperature of up to 150°C and a short-term tolerance of up to 200°C. This allows the resin grinding wheel of this embodiment to operate continuously for 2 hours at a speed of 20,000 rpm with a temperature rise of ≤30°C, thus avoiding thermal deformation.

[0056] Preferably, in the method for preparing the resin grinding wheel of this embodiment, in step S4, 90% of the submicrostructure abrasive material mass 4 screened in step S3, 8% of the resin binder 5 and 2% of the filler 6 are mixed.

[0057] This embodiment provides a resin grinding wheel, comprising a surface layer and an inner layer. The surface layer is formed by bonding a plurality of submicrostructured abrasive agglomerates 4 with a resin binder 5; the submicrostructured abrasive agglomerates 4 are formed by bonding a plurality of micro-powder abrasives 2 with a vitrified binder 1; and the inner layer includes a filler 6.

[0058] This embodiment provides a comparative example of the resin grinding wheel of this embodiment and a traditional resin grinding wheel.

[0059] Application scenario: Processing of spiral chip grooves on a certain type of carbide micro-drill (0.8mm diameter, 5mm blade length).

[0060] Comparison group settings:

[0061] Traditional resin grinding wheel: the abrasive is ordinary CBN (particle size 20μm~30μm), and the resin bond content is 15%;

[0062] The resin grinding wheel of this embodiment has a gradient structure design with CBN submicrostructure abrasive material group 4 (particle size 10μm to 20μm), a resin binder content of 8%, a surface layer containing 95% high-density submicrostructure abrasive material group 4, and an inner layer containing 20% ​​silicon carbide filler.

[0063] Processing parameters: spindle speed: 20000rpm; feed speed: 0.5mm / s; cooling method: dry grinding.

[0064] index Traditional resin grinding wheel The resin grinding wheel of this embodiment Surface roughness Ra(um) 0.2～0.35 0.08～0.1 Repair cycle (pieces) 50～80 180～200 Grinding wheel temperature rise (℃) 45～50 25～28 Slot width tolerance (um) ±3.5 ±0.8 Processing chipping rate 12％ ＜2％

[0065] Based on the above-mentioned ideal embodiments of this application, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of this application. The technical scope of this application is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a resin grinding wheel, characterized in that: The following steps are involved: S1, abrasive is prepared by mixing 8% to 12% of vitrified binder, 75% to 90% of micro-powder abrasive, 0% to 5% of filler, and 8% to 10% of organic solvent; S2, sintering to bond the ceramic binder and the micro-powder abrasive to form a submicrostructured abrasive mass; S3, cooling and cleaning the submicrostructure abrasive material mass; S4, mixing 89% to 91% of the submicrostructured abrasive material mass obtained in S3, 7.5% to 8.5% of a resin binder, and 1.5% to 2.5% of a filler, and filling the mixture into a mold for pre-pressing to form a grinding wheel blank; S5, dressing the working surface of the grinding wheel blank.

2. The method for preparing a resin grinding wheel according to claim 1, wherein In step S2, the sintering temperature is 900°C to 1200°C.

3. The method for preparing a resin grinding wheel according to claim 2, wherein: In step S4, the step of filling the mold into a pre-pressing molding step is: hot pressing and curing at 180° C. and 15 MPa for 2 hours.

4. The method for preparing a resin grinding wheel according to any one of claims 1 to 3, wherein: The micro-powder abrasive is one or more of cubic boron nitride abrasive, microcrystalline ceramic corundum abrasive, and green silicon carbide abrasive.

5. The method for preparing a resin grinding wheel according to any one of claims 1 to 3, characterized in that: In step S5, the working surface of the grinding wheel blank is sharpened by laser.

6. The method for preparing a resin grinding wheel according to any one of claims 1 to 3, characterized in that: The filler used in step S4 includes silicon carbide filler.

7. The method for preparing a resin grinding wheel according to any one of claims 1 to 3, characterized in that: In step S3, after cleaning the submicrostructure abrasive agglomerates, the submicrostructure abrasive agglomerates with a particle size of 5 μm to 20 μm are screened out.

8. The method for preparing a resin grinding wheel according to any one of claims 1 to 3, characterized in that: In step S4, the resin binder is a phenolic resin binder.

9. A resin grinding wheel, characterized in that: include: The surface layer is formed by bonding and compounding several submicrostructured abrasive material groups with a resin binder; The submicrostructured abrasive material mass is formed by bonding a plurality of micro-powder abrasives through a ceramic binder; The inner layer includes the filler.

10. A resin grinding wheel, characterized in that: The resin grinding wheel is prepared by the preparation method of any one of claims 1 to 8.

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