A composite grinding wheel based on ceramic material and a method for producing the same

Abstract

The application discloses a kind of composite grinding wheel based on ceramic material and preparation method thereof, belong to abrasive tool preparation technical field, for solving the technical problem that the structural stability and strength of composite grinding wheel in prior art need to be further improved;The application relates to a kind of composite grinding wheel, by introducing auxiliary glass phase, whisker toughening phase, yttrium stabilized zirconia ceramic crystal nucleus powder and particle reinforced phase in composite grinding wheel formula, make auxiliary glass phase participate in combination and interface transition, whisker toughening phase play bridging toughening effect, yttrium stabilized zirconia ceramic crystal nucleus powder and particle reinforced phase provide stable support and local reinforcement effect, to improve the internal organization uniformity and combination state of composite grinding wheel, inhibit crack propagation and local damage, improve the use reliability and service stability of composite grinding wheel.

Description

Technical Field

[0001] This invention relates to the field of abrasive preparation technology, specifically to a composite grinding wheel based on ceramic materials and its preparation method. Background Technology

[0002] In the prior art, grinding wheels, especially ceramic bonded grinding wheels and composite grinding wheels, are usually made of abrasives such as corundum, silicon carbide, cubic boron nitride or diamond as the main body, combined with glass binders, ceramic fillers, pore-forming materials and other inorganic additives. They are made by mixing, molding, drying and firing. These grinding wheels are widely used for grinding, dressing and surface treatment of metals, stone, glass, ceramics and composite materials. For different working conditions, the prior art also adjusts the binder composition, particle size distribution, pore structure and the type of filler to balance the formability, grinding effect and service life of the grinding wheel.

[0003] However, in existing composite grinding wheels, there is often a lack of matching between the bonding phase and the abrasive particles and reinforcing fillers. The continuity of the bonding bridge formed during the firing process is limited, and uneven coating, irregular pore boundaries, and insufficient interface transition are prone to occur in local areas. Especially when multiple inorganic components coexist, the differences in thermal shrinkage and rigidity between different components are more likely to lead to local stress concentration, causing relatively weak parts to form inside the grinding wheel. Although such structural defects may not be obvious in the forming stage, they are prone to induce local cracking, collapse, or structural instability during subsequent loading, impact, or high-speed rotation.

[0004] In addition, existing technologies often use single-particle fillers or ordinary short fibers and whiskers to reinforce or toughen grinding wheels. However, the dispersion, interfacial bonding, and synergistic load-bearing effect of these components in the matrix are often not ideal. Some reinforcing phases are more isolated and difficult to achieve effective support, crack deflection, and interfacial buffering at the same time. When the grinding wheel is subjected to high linear velocity, intermittent impact, or continuous surface erosion, microcracks may still propagate along the interface or the area near the pores, making it difficult to balance the overall load-bearing capacity, damage resistance, and service stability. Therefore, there is still room for further improvement.

[0005] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a composite grinding wheel based on ceramic materials and its preparation method, in order to solve the technical problem that the structural stability and strength of composite grinding wheels in the prior art need to be further improved.

[0007] The objective of this invention can be achieved through the following technical solutions: A composite grinding wheel based on ceramic materials, wherein the composite grinding wheel is a composite grinding wheel with an alumina matrix as the continuous phase, a particle-reinforcing phase and a whisker-toughening phase dispersed therein, and an auxiliary glass phase distributed among the components; The particle-reinforcing phase is yttrium-stabilized zirconia particles with an aluminum phosphate coating on their surface. The whisker toughening phase is an aluminoborate whisker bundle with a silica anchoring layer on the surface and at the nodes. The auxiliary glass phase is an oxyfluoroborosilicate auxiliary glass powder containing bismuth, zinc, fluorine, boron and silicon structural units.

[0008] Furthermore, the preparation method of the auxiliary glass phase is as follows: bismuth trioxide, zinc fluoride, silicon dioxide and boric acid are added to a mixer and stirred until uniformly mixed, then transferred to a crucible, and the crucible is placed in a high-temperature furnace and heated to 780-810℃, held for 25-35 minutes, and then post-processed to obtain the auxiliary glass phase.

[0009] Furthermore, in the preparation of the auxiliary glass phase, the molar ratio of bismuth trioxide, zinc fluoride, silicon dioxide and boric acid is 1:1.2-1.5:1.6-2.0:2.0-2.5. The post-processing includes: after heat preservation, the melt is poured onto a cooling plate to cool and obtain a block glass body, and then the block glass body is crushed, ground and passed through a 250-350 mesh sieve to obtain the auxiliary glass phase.

[0010] Furthermore, the particle-reinforcing phase is prepared by the following method: A1. Add deionized water, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and urea to the reaction vessel and stir. After mixing evenly, heat the reaction vessel to 185-195℃ and keep it at that temperature for 8-12 hours. Post-processing yields yttrium-stabilized zirconium oxide ceramic nucleus powder. A2. Add anhydrous ethanol, deionized water and yttrium-stabilized zirconia ceramic nuclei powder to the reactor and stir. After the mixture is evenly dispersed, add aluminum nitrate nonahydrate and continue stirring until evenly dispersed. Then add 85wt% phosphoric acid and heat the reactor to 165-175℃. Keep the temperature for 5-7 hours. The post-treatment yields the particle-reinforced phase.

[0011] Further, in step A1, the molar ratio of zirconium oxychloride octahydrate, yttrium nitrate hexahydrate, and urea is 1:0.048-0.058:4.8-6.2, and the amount of deionized water added is 11-14 mL / g based on zirconium oxychloride octahydrate. The post-treatment includes: after the reaction is completed, the solid is naturally cooled to room temperature, filtered and collected, the solid is washed with deionized water until the conductivity of the filtrate is less than 50 μS / cm, the solid is then placed in a drying oven at 90-110℃ and dried for 6-8 hours, and then placed in an air atmosphere and heated to 620-680℃ at 2-4℃ / min and held for 40-60 minutes. After cooling, it is passed through a 200-mesh sieve to obtain yttrium-stabilized zirconium oxide ceramic nucleus powder. Further, in step A2, the ratio of yttrium-stabilized zirconia ceramic nucleus powder to aluminum nitrate nonahydrate is 1g:0.48-0.60g, and the amounts of anhydrous ethanol, deionized water, and 85wt% phosphoric acid added are based on the yttrium-stabilized zirconia ceramic nucleus powder, which are 6.5-9.8mL / g, 2.4-3.7mL / g, and 0.08-0.13mL / g, respectively. The post-treatment includes: after the reaction is completed, the solid is naturally cooled to room temperature, filtered and collected, and the solid is washed once each with anhydrous ethanol and deionized water. The solid is then dried in a drying oven at 85-95℃ for 5-7h, and then heated to 730-770℃ at a rate of 1.5-2.5℃ / min under air atmosphere and held for 40-60min. After cooling, the solid is passed through a 200-mesh sieve to obtain the particulate-reinforced phase.

[0012] Furthermore, the preparation method of the whisker toughening phase is as follows: alumina, boric acid, silicon dioxide and anhydrous sodium sulfate are added to a mixer and stirred and mixed evenly, then transferred to a crucible, and the crucible is placed in a high-temperature furnace and heated to 1020-1060℃, held for 2.5-3.5h, and then post-processed to obtain the whisker toughening phase.

[0013] Furthermore, in the preparation of the whisker toughening phase, the molar ratio of alumina, boric acid, and silicon dioxide is 1:0.42-0.47:0.10-0.15, and the amount of anhydrous sodium sulfate added is 4.0-5.5 g / g based on alumina. The post-treatment includes: after the heat preservation is completed, the solid is cooled to below 300°C and taken out. The obtained solid is transferred to hot water at 75-85°C for washing, the solid is filtered and collected, and then the solid is placed in a drying oven at 100-110°C for drying for 5-7 hours. After cooling, it is slightly depolymerized and passed through a 150-mesh sieve to obtain the whisker toughening phase.

[0014] This invention also discloses a method for preparing a composite grinding wheel based on ceramic materials, comprising the following steps: S1. Weigh 200-240 parts of deionized water and 16-20 parts of polyvinyl alcohol by weight and add them to a mixing tank. Heat and stir until the polyvinyl alcohol is completely dissolved. Then cool down and add 1.6-2.2 parts of boric acid and stir evenly. Then add 720-840 parts of alumina, 80-100 parts of particle reinforcing phase, 26-34 parts of whisker toughening phase and 63-77 parts of auxiliary glass phase in sequence. Mix evenly and granulate. After post-treatment, alumina-based composite grinding wheel granules are obtained. S2. Add alumina-based composite grinding wheel granules into a mold and press them into shape. After demolding, transfer the molded blank to a sintering furnace and heat it to a set temperature for firing. After firing, cool it to room temperature with the furnace and trim the product to obtain a composite grinding wheel.

[0015] Further, in step S1, the post-processing includes: sizing the granulated wet particles through a 14-18 mesh sieve, then drying the particles in a drying oven at 75-85℃ for 3-5 hours, and after cooling, passing them through a 12-20 mesh sieve to obtain alumina-based composite grinding wheel granules. Furthermore, in step S2, the pressing pressure is 110-130 MPa, and the holding time is 20-40 s; the programmed temperature rise firing includes: heating to 280-320℃ at 1.5-2.5℃ / min and holding for 0.8-1.2 h, then heating to 480-520℃ at 1.5-2.5℃ / min and holding for 0.8-1.2 h, followed by heating to 870-890℃ at 2.5-3.5℃ / min and holding for 1.5-2.5 h.

[0016] The present invention has the following beneficial effects: In the final microstructure formed by firing, the auxiliary glass phase does not merely exist as a general binding medium, but is distributed among the abrasive particles, particle-reinforced phase, and whisker-toughened phase, forming a continuous transition region. The particle-reinforced phase, being within this continuous phase, is less likely to form abrupt interface voids around it, and the boundaries of the bonding bridges are less likely to show obvious interruptions. The whisker-toughened phase further penetrates into the adjacent areas of the interface, dispersing the minute defects that would easily accumulate locally during firing shrinkage. As a result, the spatial connection between the various components within the system is smoother, and the pore morphology, the distribution of the binding phase, and the state of the skeletal support correspond to each other. The microstructure of the fired body is closer to a balanced and stable configuration.

[0017] When a composite grinding wheel is subjected to bending stress and surface erosion, the particle-reinforcing phase is the primary component in the dominant response. This phase is located on the bonding bridge and stress transmission path, preventing the load from being directly concentrated on the auxiliary glass phase enrichment area. The auxiliary glass phase then stably connects the particle-reinforcing phase with the surrounding abrasive, maintaining the integrity during the stress transformation process and reducing localized detachment damage. In parallel, the whisker-toughening phase does not bear the main load, but it continuously affects the crack propagation mode, making the initial microcracks more likely to deflect, bifurcate, or be restrained locally. Thus, the material exhibits not a simple brittle response after hardening under external force, but a working state in which load-bearing, interface constraint, and damage propagation are coordinated. The macroscopic characterization also shows a relatively consistent trend of change.

[0018] Under high-speed rotation, the key challenge for the material system is not single-point bearing in the sense of static strength, but whether defects will evolve into rapid instability under continuous centrifugal stress. The whisker-toughening phase, arranged in the intersection region of the bonding phase and the particle-reinforcing phase, continuously intervenes in this evolution process: when local disturbances occur, it does not simply increase the rigidity of the system, but changes the ease with which cracks propagate along the interface; the particle-reinforcing phase maintains the continuity of the skeleton in the outer region, preventing stress from suddenly accumulating at local weak points; the auxiliary glass phase ensures that the abrasive, particles and whiskers remain completely interlocked, so that the interface transition under dynamic conditions does not lose control. Throughout the rotation process, the structural response exhibits strong integrity and continuity, which is significantly different from the local sudden failure path commonly seen in single-reinforcing systems. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a SEM image of the particle-reinforced phase prepared in Example 3 of the present invention; Figure 2 This is a SEM image of the auxiliary glass phase prepared in Example 6 of the present invention; Figure 3 This is a SEM image of the whisker-toughened phase prepared in Example 6 of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In this application, the alumina used was purchased from Shanghai Maclean Biotechnology Co., Ltd., with item number A664978; the silica used was purchased from Shanghai Maclean Biotechnology Co., Ltd., with item number S817558.

[0023] Example 1

[0024] This embodiment provides a method for preparing a particle-reinforced phase, including the following steps: Step I: Preparation of yttrium-stabilized zirconia ceramic nuclei powder Weigh out 110.0 mL of deionized water, 10.0 g of zirconium oxychloride octahydrate, 0.6 g of yttrium nitrate hexahydrate, and 8.9 g of urea and add them to the reaction vessel. Stir and mix thoroughly. Heat the reaction vessel to 185 °C and keep it at that temperature for 8 hours. After the reaction is complete, allow it to cool naturally to room temperature. Filter and collect the solid. Wash the solid with deionized water until the conductivity of the filtrate is less than 50 μS / cm. Then, place the solid in a drying oven at 90 °C and dry it for 6 hours. Subsequently, place it in an air atmosphere and heat it to 620 °C at a rate of 2 °C / min and keep it at that temperature for 40 minutes. After cooling, pass it through a 200-mesh sieve to obtain yttrium-stabilized zirconium oxide ceramic nucleus powder.

[0025] Step II: Preparation of particulate-reinforced phase Weigh out 65.0 mL of anhydrous ethanol, 24.0 mL of deionized water, and 10.0 g of yttrium-stabilized zirconia ceramic nucleus powder and add them to the reaction vessel. Stir and disperse evenly, then add 4.8 g of aluminum nitrate nonahydrate and continue stirring until evenly mixed. Add 0.8 mL of 85 wt% phosphoric acid, heat the reaction vessel to 165 °C, and keep it at that temperature for 5 h. After the reaction is complete, allow it to cool naturally to room temperature, filter and collect the solid. Wash the solid once with anhydrous ethanol and once with deionized water, then dry it in an 85 °C drying oven for 5 h. Subsequently, place it in an air atmosphere and heat it to 730 °C at a rate of 1.5 °C / min for 40 min. After cooling, pass it through a 200-mesh sieve to obtain the particulate-reinforced phase.

[0026] The reaction principle for preparing particulate-reinforced phases is as follows: In a hydrothermal system containing zirconium salts, yttrium salts, and urea, urea slowly decomposes upon heating, releasing alkaline components. This causes zirconium and yttrium ions to hydrolyze uniformly, forming a zirconium-yttrium precursor precipitate. After washing, drying, and calcination, this precipitate is transformed into yttrium-stabilized zirconia ceramic nuclei. Subsequently, in an ethanol-water mixed medium, aluminum nitrate provides the aluminum source, and 85 wt% phosphoric acid provides the phosphorus source. Under heating conditions, these two components coordinate, hydrolyze, and condense to form an aluminum-phosphorus oxygen structure. The introduced yttrium-stabilized zirconia nuclei serve as the inorganic solid-phase core, participating in the loading and composite of this structure. Subsequent heat treatment removes nitrate and volatile components from the precursor, completing the inorganicization of the system and yielding a particulate-reinforced phase.

[0027] The mechanism of action of particulate reinforcing phase in composite grinding wheels is as follows: In this process, the yttrium-stabilized zirconia ceramic nucleus powder obtained in step I provides a ceramic core source with high structural stability, rigid support capacity and interfacial activity for the subsequent composite system. After entering the final composite grinding wheel, it not only constitutes an important hard core in the particle reinforcement unit to bear local load and maintain structural stability, but also helps to reduce local mismatch caused by shrinkage differences, thermal stress fluctuations and interfacial disturbances during firing and service. The particle-reinforced phase obtained in step II further introduces an inorganic composite structure with interface transition characteristics around the aforementioned ceramic core. This makes the reinforcing unit no longer just an isolated and dispersed hard particle, but more inclined to participate in the construction of bonding bridges, the maintenance of interface connections, and the adjustment of local stress. As a result, a multi-layered organizational relationship is formed inside the composite grinding wheel, in which rigid support points, transition coating layers, and surrounding bonding phases cooperate with each other. Consequently, the pore boundaries, particle contact states, and interface continuity around the reinforcing phase are more easily coordinated, and the internal load transmission path is more dispersed. Microcracks are less likely to penetrate rapidly along a single weak area during initiation and propagation. This results in a more balanced and continuous performance response in terms of bulk density, apparent porosity, flexural load-bearing capacity, surface erosion resistance, and overall stability under high-speed rotation conditions.

[0028] Example 2

[0029] This embodiment provides a method for preparing a particle-reinforced phase, including the following steps: Step I: Preparation of yttrium-stabilized zirconia ceramic nuclei powder Weigh out 140.0 mL of deionized water, 10.0 g of zirconium oxychloride octahydrate, 0.6 g of yttrium nitrate hexahydrate, and 11.6 g of urea and add them to the reaction vessel. Stir and mix thoroughly. Heat the reaction vessel to 195 °C and keep it at that temperature for 12 h. After the reaction is complete, allow it to cool naturally to room temperature. Filter and collect the solid. Wash the solid with deionized water until the conductivity of the filtrate is less than 50 μS / cm. Then, place the solid in a drying oven at 110 °C and dry it for 8 h. Subsequently, place it in an air atmosphere and heat it to 680 °C at a rate of 4 °C / min and keep it at that temperature for 60 min. After cooling, pass it through a 200-mesh sieve to obtain yttrium-stabilized zirconium oxide ceramic nucleus powder.

[0030] Step II: Preparation of particulate-reinforced phase Weigh out 98.0 mL of anhydrous ethanol, 37.0 mL of deionized water, and 10.0 g of yttrium-stabilized zirconia ceramic nucleus powder and add them to the reaction vessel. Stir and disperse evenly, then add 6.0 g of aluminum nitrate nonahydrate and continue stirring until evenly mixed. Add 1.3 mL of 85 wt% phosphoric acid, heat the reaction vessel to 175 °C, and keep it at that temperature for 7 h. After the reaction is complete, allow it to cool naturally to room temperature, filter and collect the solid. Wash the solid once with anhydrous ethanol and once with deionized water, then dry it in a 95 °C drying oven for 7 h. Subsequently, place it in an air atmosphere and heat it to 770 °C at a rate of 2.5 °C / min for 60 min. After cooling, pass it through a 200-mesh sieve to obtain the particulate-reinforced phase.

[0031] Example 3

[0032] This embodiment provides a method for preparing a particle-reinforced phase, including the following steps: Step I: Preparation of yttrium-stabilized zirconia ceramic nuclei powder Weigh out 130.0 mL of deionized water, 10.0 g of zirconium oxychloride octahydrate, 0.6 g of yttrium nitrate hexahydrate, and 10.3 g of urea and add them to the reaction vessel. Stir and mix thoroughly. Heat the reaction vessel to 190 °C and keep it at that temperature for 10 h. After the reaction is complete, allow it to cool naturally to room temperature. Filter and collect the solid. Wash the solid with deionized water until the conductivity of the filtrate is less than 50 μS / cm. Then, place the solid in a drying oven at 100 °C and dry it for 7 h. Subsequently, place it in an air atmosphere and heat it to 650 °C at a rate of 3 °C / min and keep it at that temperature for 50 min. After cooling, pass it through a 200-mesh sieve to obtain yttrium-stabilized zirconium oxide ceramic nucleus powder.

[0033] Step II: Preparation of particulate-reinforced phase Weigh out 82.0 mL of anhydrous ethanol, 31.0 mL of deionized water, and 10.0 g of yttrium-stabilized zirconia ceramic nucleus powder and add them to the reaction vessel. Stir and disperse evenly, then add 5.4 g of aluminum nitrate nonahydrate and continue stirring until evenly mixed. Add 1.1 mL of 85 wt% phosphoric acid, heat the reaction vessel to 170 °C, and keep it at that temperature for 6 h. After the reaction is complete, allow it to cool naturally to room temperature, filter and collect the solid. Wash the solid once with anhydrous ethanol and once with deionized water, then dry it in a 90 °C drying oven for 6 h. Subsequently, heat it to 750 °C at 2.0 °C / min under an air atmosphere and keep it at that temperature for 50 min. After cooling, pass it through a 200-mesh sieve to obtain the particulate-reinforced phase.

[0034] Example 4

[0035] This embodiment provides a method for preparing a composite grinding wheel based on ceramic materials, including the following steps: Step 1: Preparation of the auxiliary glass phase Weigh out 10.0g of bismuth trioxide, 2.7g of zinc fluoride, 2.1g of silicon dioxide and 2.7g of boric acid, add them to a mixer and stir until evenly mixed. Transfer the mixture to a crucible and place it in a high-temperature furnace to heat to 780℃. Hold the temperature for 25 minutes. After holding, pour the melt onto a cooling plate to cool and obtain a block glass body. Then crush, grind and pass the block glass body through a 250-mesh sieve to obtain the auxiliary glass phase.

[0036] The reaction principle for preparing the auxiliary glass phase is as follows: In a mixed system composed of bismuth trioxide, zinc fluoride, silicon dioxide, and boric acid, the components melt at high temperature to form a homogeneous liquid phase. Elements such as Bi, Zn, Si, and B are redistributed in the form of oxygen coordination or fluorine-containing coordination. Silicon dioxide and boric acid provide silicon-oxygen network units and boron-oxygen network units, respectively. Bismuth trioxide and zinc fluoride participate in the construction and regulation of the glass network, transforming the system from the original crystalline or molecular raw materials into a continuous disordered glassy structure. After the melt is cooled, the atomic arrangement inside the system is fixed, forming a multi-element amorphous solid based on silicon-oxygen and boron-oxygen structural units and containing bismuth and zinc components. After crushing, grinding, and sieving, the auxiliary glass phase is obtained.

[0037] The mechanism of action of the auxiliary glass phase in composite grinding wheels is as follows: The anti-auxiliary glass phase obtained by this process is essentially a multi-element amorphous functional phase based on silicon-oxygen and boron-oxygen structural units and modified by the introduction of bismuth and zinc components. Its role in the final composite grinding wheel is not simply to increase the content of low-melting-point substances, but rather to comprehensively participate in the formation of liquid phase, interface wetting, particle containment and structural coordination during the firing process. After the auxiliary glass phase enters the system, it can provide a more adaptable transitional connecting medium between abrasive particles, particle reinforcement units and other inorganic phases, so as to alleviate the originally prominent interface rigidity differences between different components and promote the formation of bonding bridges to be more continuous and uniform. On the other hand, the network tunability of its amorphous structure makes it easier to spread, fill and cover at local pore boundaries, particle contact areas and near micro-defects, thereby improving the integrity of the structure and reducing the tendency of stress concentration. As a result, the internal structure of the composite grinding wheel after firing is more likely to form a combined state with both connectivity and coordination. This helps to maintain a suitable bulk density and apparent porosity, and also makes the load transfer path more continuous during loading. Microcracks are less likely to spread rapidly along the weak parts of the interface. As a result, the overall stability response of the final product under room temperature bending load, surface erosion resistance and high speed rotation conditions shows a more balanced tendency.

[0038] Step 2: Preparation of whisker-toughened phase Weigh out 10.0g of alumina, 2.6g of boric acid, 0.6g of silicon dioxide and 40.0g of anhydrous sodium sulfate and add them to a mixer. Stir and mix evenly, then transfer the mixture to a crucible. Place the crucible in a high-temperature furnace and heat it to 1020℃. Hold the temperature for 2.5h. After the holding time is over, cool the crucible to below 300℃ and remove it. Transfer the obtained solid to 75℃ hot water for washing, filter and collect the solid. Place the solid in a drying oven at 100℃ and dry it for 5h. After cooling, slightly depolymerize and pass it through a 150-mesh sieve to obtain the whisker toughening phase.

[0039] The reaction principle for preparing whisker-toughened phases is as follows: In a system composed of alumina, boric acid, silicon dioxide, and anhydrous sodium sulfate, boric acid dehydrates upon heating to form boron oxide, while anhydrous sodium sulfate forms a molten salt medium at high temperatures, allowing the aluminum, boron, and silicon components to be in a state of more complete contact and mass transfer. A solid-liquid coupling reaction occurs between alumina, boron oxide, and silicon dioxide, and structural units such as aluminum-oxygen tetrahedra, boron-oxygen trigonal bodies, and silicon-oxygen tetrahedra in the system rearrange and combine, gradually forming a stable inorganic crystalline phase. During furnace cooling, this crystalline phase precipitates from the high-temperature reaction system and maintains a certain crystal morphology. The subsequent hot water washing is essentially to remove residual anhydrous sodium sulfate and other soluble salts, thereby separating the target crystalline solid phase.

[0040] The mechanism of action of whisker toughening phase in composite grinding wheels is as follows: The whisker toughening phase obtained by this process can be regarded as a functional toughening component composed of inorganic structural units related to aluminum, boron, and silicon and having specific aspect ratio characteristics. Its role in the final composite grinding wheel is not simply filling, but participating in the internal structure regulation through the bridging, restraint, and energy dissipation effects given by its whisker morphology. After the whisker toughening phase enters the system, it can form multi-point contact and local overlap between abrasive particles, bonding phase, and particle reinforcement units, enhance the spatial connection between different structural units, and make the internal skeleton support relationship of the composite grinding wheel more complete. On the other hand, the whisker-like structure is more likely to deflect, bifurcate, bridge, and pull out energy of microcracks during the stress process, thereby reducing the tendency of cracks to quickly penetrate along a single weak interface and alleviating local stress concentration. At the same time, the interlocking effect formed between the toughening phase and the surrounding bonding phase also helps to maintain the structural stability of the pore boundary and the adjacent area of ​​the interface, so that the microstructure after firing can obtain better overall continuity while maintaining certain porosity characteristics. As a result, the composite grinding wheel's damage resistance and structural stability under room temperature bending load, surface erosion resistance, and high-speed rotation conditions are all improved, which means that the material can more easily achieve a coordinated unity between strength, toughness and service reliability.

[0041] Step 3: Preparation of alumina-based composite grinding wheel granules Weigh out 200 parts by weight of deionized water and 16 parts by weight of polyvinyl alcohol and add them to a mixing tank. Heat and stir until the polyvinyl alcohol is completely dissolved. Then cool down and add 1.6 parts by weight of boric acid and stir evenly. Then add 720 parts by weight of alumina, 80 parts by weight of the particle-reinforcing phase prepared in Example 1, 26 parts by weight of the whisker-toughening phase and 63 parts by weight of the auxiliary glass phase in sequence. After mixing evenly, granulate. The granulated wet particles are sieved through a 14-mesh sieve and then placed in a drying oven at 75°C for 3 hours. After cooling, pass through a 12-mesh sieve to obtain alumina-based composite grinding wheel granules.

[0042] Step 4: Preparation of composite grinding wheel Alumina-based composite grinding wheel granules were added to a mold and pressed into shape. The mold cavity dimensions were 100mm outer diameter, 20mm inner diameter, and 10mm thickness. The pressing pressure was 120MPa, and the holding pressure was 30s. After demolding, the formed blank was transferred to a sintering furnace for programmed heating and firing. The firing regime was as follows: first, the temperature was increased to 280℃ at 1.5℃ / min and held for 0.8h; then, the temperature was increased to 480℃ at 1.5℃ / min and held for 0.8h; then, the temperature was increased to 870℃ at 2.5℃ / min and held for 1.5h. After firing, the blank was cooled to room temperature with the furnace and the product was trimmed to obtain a composite grinding wheel with specifications of Φ100mm×Φ20mm×10mm.

[0043] The reaction principle for preparing composite grinding wheels is as follows: In the deionized water-polyvinyl alcohol system, polyvinyl alcohol is dissolved by heating to form a continuous organic medium. Boric acid is dispersed in this medium and together with alumina, particle-reinforcing phase, whisker-toughening phase and auxiliary glass phase, it constitutes a multi-component mixed system. Alumina is the main inorganic phase, and the other components are uniformly embedded in the form of dispersed phases. During the pressing process, mechanical interlocking and spatial stacking between particles mainly occur, and the granular material obtains a stable green body structure. Under the firing conditions, the organic components are decomposed by heat and removed, and the auxiliary glass phase gradually softens. The original physical contact between inorganic particles in the system is transformed into a bonded state characterized by glass phase connection. At the same time, each inorganic phase completes densification and rearrangement under thermal action, and finally forms a composite solidified body composed of alumina main phase, reinforcing phase, whisker phase and glass phase.

[0044] Example 5

[0045] This embodiment provides a method for preparing a composite grinding wheel based on ceramic materials, including the following steps: Step 1: Preparation of the auxiliary glass phase Weigh out 10.0g of bismuth trioxide, 3.3g of zinc fluoride, 2.5g of silicon dioxide and 3.3g of boric acid, add them to a mixer and stir until evenly mixed. Transfer the mixture to a crucible and place it in a high-temperature furnace. Heat the crucible to 810℃ and hold for 35 minutes. After holding, pour the melt onto a cooling plate to cool and obtain a block glass body. Crush, grind and pass the block glass body through a 350-mesh sieve to obtain the auxiliary glass phase.

[0046] Step 2: Preparation of whisker-toughened phase Weigh out 10.0g of alumina, 2.8g of boric acid, 0.8g of silicon dioxide and 55.0g of anhydrous sodium sulfate and add them to a mixer. Stir and mix evenly, then transfer the mixture to a crucible. Place the crucible in a high-temperature furnace and heat it to 1060℃. Hold the temperature for 3.5h. After holding, cool the mixture with the furnace to below 300℃ and remove it. Transfer the obtained solid to 85℃ hot water for washing, filter and collect the solid. Place the solid in a drying oven at 110℃ and dry for 7h. After cooling, slightly depolymerize and pass it through a 150-mesh sieve to obtain the whisker toughened phase.

[0047] Step 3: Preparation of alumina-based composite grinding wheel granules Weigh out 240 parts by weight of deionized water and 20 parts by weight of polyvinyl alcohol and add them to a mixing tank. Heat and stir until the polyvinyl alcohol is completely dissolved. Then cool down and add 2.2 parts by weight of boric acid and stir evenly. Then add 840 parts by weight of alumina, 100 parts by weight of the particle-reinforcing phase prepared in Example 2, 34 parts by weight of the whisker-toughening phase and 77 parts by weight of the auxiliary glass phase in sequence. After mixing evenly, granulate. The granulated wet particles are sieved through an 18-mesh sieve and then placed in a drying oven at 85°C for 5 hours. After cooling, pass through a 20-mesh sieve to obtain alumina-based composite grinding wheel particles.

[0048] Step 4: Preparation of composite grinding wheel Alumina-based composite grinding wheel granules were added to a mold and pressed into shape. The mold cavity dimensions were 100mm outer diameter, 20mm inner diameter, and 10mm thickness. The pressing pressure was 120MPa, and the holding pressure was 30s. After demolding, the formed blank was transferred to a sintering furnace for programmed heating and firing. The firing regime was as follows: first, the temperature was increased to 320℃ at 2.5℃ / min and held for 1.2h; then, the temperature was increased to 520℃ at 2.5℃ / min and held for 1.2h; then, the temperature was increased to 890℃ at 3.5℃ / min and held for 2.5h. After firing, the blank was cooled to room temperature with the furnace and then trimmed to obtain a composite grinding wheel with specifications of Φ100mm×Φ20mm×10mm.

[0049] Example 6

[0050] This embodiment provides a method for preparing a composite grinding wheel based on ceramic materials, including the following steps: Step 1: Preparation of the auxiliary glass phase Weigh out 10.0g of bismuth trioxide, 3.1g of zinc fluoride, 2.3g of silicon dioxide and 3.1g of boric acid, add them to a mixer and stir until evenly mixed. Transfer the mixture to a crucible and place it in a high-temperature furnace to heat to 800℃. Hold the temperature for 30 minutes. After holding, pour the melt onto a cooling plate to cool and obtain a block glass body. Then crush, grind and pass the block glass body through a 300-mesh sieve to obtain the auxiliary glass phase.

[0051] Step 2: Preparation of whisker-toughened phase Weigh out 10.0g of alumina, 2.7g of boric acid, 0.8g of silicon dioxide and 48.0g of anhydrous sodium sulfate and add them to a mixer. Stir and mix evenly, then transfer the mixture to a crucible. Place the crucible in a high-temperature furnace and heat it to 1040℃. Hold the temperature for 3.0h. After holding, cool the mixture with the furnace to below 300℃ and remove it. Transfer the obtained solid to 80℃ hot water for washing, filter and collect the solid. Place the solid in a drying oven at 105℃ and dry it for 6h. After cooling, slightly depolymerize and pass it through a 150-mesh sieve to obtain the whisker toughening phase.

[0052] Step 3: Preparation of alumina-based composite grinding wheel granules Weigh out 220 parts by weight of deionized water and 18 parts by weight of polyvinyl alcohol and add them to a mixing tank. Heat and stir until the polyvinyl alcohol is completely dissolved. Then cool down and add 1.9 parts by weight of boric acid and stir evenly. Then add 780 parts by weight of alumina, 90 parts by weight of the particle-reinforcing phase prepared in Example 3, 30 parts by weight of the whisker-toughening phase and 70 parts by weight of the auxiliary glass phase in sequence. After mixing evenly, granulate. The granulated wet particles are sieved through a 16-mesh sieve and then placed in a drying oven at 80°C for 4 hours. After cooling, pass through a 16-mesh sieve to obtain alumina-based composite grinding wheel granules.

[0053] Step 4: Preparation of composite grinding wheel Alumina-based composite grinding wheel granules were added to a mold and pressed into shape. The mold cavity dimensions were 100mm outer diameter, 20mm inner diameter, and 10mm thickness. The pressing pressure was 120MPa, and the holding pressure was 30s. After demolding, the formed blank was transferred to a sintering furnace for programmed heating and firing. The firing regime was as follows: first, the temperature was increased to 300℃ at 2.0℃ / min and held for 1.0h; then, the temperature was increased to 500℃ at 2.0℃ / min and held for 1.0h; then, the temperature was increased to 880℃ at 3.0℃ / min and held for 2.0h. After firing, the blank was cooled to room temperature with the furnace and the product was trimmed to obtain a composite grinding wheel with specifications of Φ100mm×Φ20mm×10mm.

[0054] Comparative Example 1 The difference between this comparative example and Example 6 is that in step three, the particulate reinforcing phase is omitted, and an equal amount of alumina is used to replace the particulate reinforcing phase.

[0055] Comparative Example 2 The difference between this comparative example and Example 6 is that zinc fluoride was omitted in step one.

[0056] Comparative Example 3 The difference between this comparative example and Example 6 is that the addition of anhydrous sodium sulfate is omitted in step two.

[0057] Performance testing: The bulk density and apparent porosity were determined according to GB / T 1966-2024 "Determination of Apparent Porosity and Bulk Density of Porous Ceramics": Ten samples were uniformly cut along the circumference from the composite grinding wheels prepared in Examples 4-6 and Comparative Examples 1-3, and processed into 10mm×10mm×10mm cubes. The edges and corners of the samples were slightly blunted and surface debris was removed. The samples were dried in a forced-air drying oven at 110±5℃ until constant weight. After being removed, they were cooled in a desiccator for 30 minutes and the dried mass was weighed. Then, deionized water was used as the impregnation medium, and the water temperature was controlled at 25±2℃. After vacuuming for 30 minutes under -0.095mPa conditions, the samples were continued to be immersed for 2 hours. The saturated mass and suspended mass were weighed respectively and calculated according to the standard. The room temperature flexural strength was determined according to GB / T 1965-2023 "Test Method for Room Temperature Flexural Strength of Porous Ceramics": Ten strip specimens were cut from the composite grinding wheels prepared in Examples 4-6 and Comparative Examples 1-3, and processed to a size of 70mm × 8.0mm × 6.0mm. The surface of the specimens was lightly polished with 800-grit metallographic sandpaper to ensure a smooth surface without visible cracks, chipping, or missing corners. Before the test, the specimens were dried in a drying oven at 105±5℃ for 2 hours and then cooled to room temperature before testing. A three-point flexural test was performed using an electronic universal testing machine. The support span was fixed at 40mm, the loading head was located at the midpoint of the specimen, the loading rate was fixed at 0.5mm / min, and the ambient temperature was 23±2℃. The fracture load of the specimens was recorded and calculated according to the standard. The test results are expressed as room temperature flexural strength in MPa. The arithmetic mean of 10 parallel samples was taken for each group of results. The hardness of the sandblasting was determined according to GB / T 2490-2018 "Testing of Hardness of Bonded Abrasives": a sandblasting hardness tester was used, with the sand chamber volume fixed at 28 cm³. 3 The nozzle orifice diameter was fixed at 5.8 mm, the distance from the nozzle to the sample surface was fixed at 9.0 mm, the air pressure was fixed at 0.15 mPa, and the spraying medium was quartz sand with a SiO2 content of not less than 95%. Six measuring points were evenly selected in the annular area 5-8 mm from the outer circle on one side of the composite grinding wheel prepared in Examples 4-6 and Comparative Examples 1-3. Each measuring point was sprayed once, and then the depth of the blasting pit was measured using a reading microscope. The sample result was the average value of the pit depth of the six measuring points. The test result was expressed as the blasting hardness pit depth value in mm. The rotational strength was determined according to GB / T 2493-2023 "Test Method for Rotational Strength of Abrasives", and the pass / fail judgment was carried out according to GB2494-2014 "Safety Requirements for Bonded Abrasives": The composite grinding wheels with specifications of Φ100mm×Φ20mm×10mm prepared in Examples 4-6 and Comparative Examples 1-3 were installed on the rotational strength testing machine and clamped with a flange matching the product. After clamping, the end face fit and coaxiality were checked. Then, the speed was increased uniformly under the condition of the protective cover being closed. The test cycle speed was fixed at 60m / s, and the corresponding test speed was fixed at 11460r / min. After reaching the set speed, the speed was held for 30s. The specimen was observed to see if there were any cracks, fissures, loosening and other failure phenomena. The test result is expressed as the rotational strength test result, i.e., pass / fail. See Table 1 for specific data; Table 1 - Performance Test Data for Each Sample <![CDATA[Volume density / g·cm 3 > 2.93 2.94 2.95 2.89 2.85 2.91 Apparent porosity / % 28.3 28.0 27.7 29.5 31.2 28.9 Room temperature flexural strength / MPa 58.4 59.3 60.2 49.6 45.8 52.4 Sandblasting hardness pit depth value / mm 1.36 1.33 1.30 1.52 1.64 1.45 Results of rotational strength test pass pass pass Not passed Not passed Not passed Data Analysis: A comparative analysis of the data in Table 1 reveals that the bulk density of the composite grinding wheel prepared in this invention is 2.93 g·cm³. 3The sample exhibits a porosity of 28.3%, a room temperature flexural strength of 58.4 MPa, and a sandblasting hardness pit depth of 1.36 mm. Simultaneously, it passes the rotational strength test, and all data are superior to the comparative example. This indicates that: In Comparative Example 1, after the interfacial transition relationship of the original heterogeneous particles in the sintering system was weakened, the bonding phase mainly exhibited a relatively simple filling and consolidation mode between the abrasive particles. The lack of stable support nodes in local areas made the volume change during the sintering shrinkage process more likely to concentrate in individual bonding parts. As a result, the correspondence between the continuity of the bonding bridge, the integrity of the transition layer and the uniformity of pore distribution was affected, and weak areas with uneven thickness or unbalanced density were more likely to form in the internal structure. Under subsequent loading and erosion conditions, the stress transmission path tended to concentrate, local disturbances were not easily dispersed and absorbed, and micro-defects were more likely to extend along the weak bonding areas, thus causing the overall material response to change from the original coordinated state to a state that was more sensitive to local defects. In Comparative Example 2, after the compositional relationship of the auxiliary glass phase was changed, the softening, spreading, interface wetting, and continuous consolidation processes during the firing stage could not maintain their original coordination. As a result, the transition state between abrasive particles, reinforcing particles, and toughening units was affected. This change was not limited to insufficient local bonding, but was further reflected in the unevenness of the bonding bridge boundary, the weakening of interface containment, and the decrease in the consistency of pore morphology. As a result, it was difficult to establish a stable correspondence between the uniformity of the microstructure and the integrity of the interface within the fired body. Local areas were more likely to become the preferred locations for stress disturbance concentration. During subsequent mechanical action and dynamic service, the structural response changed from continuous transmission to local bearing, and the original state of multi-component collaborative sharing was weakened, which in turn caused the overall service characteristics to show unfavorable changes. In Comparative Example 3, after the toughening component failed to form the original morphological characteristics, the cross-boundary constraint effect it provided in the region where the bonding phase and reinforcing particles intersected was significantly weakened. As a result, the propagation path of microcracks formed inside the material lacked effective regulation. This effect was first manifested in the insufficient deflection, dispersion and slow release links in the defect evolution process, making local cracks more inclined to continue to extend along the adjacent area of ​​the interface, rather than being easily passivated step by step. At the same time, although the sintered body still retained the basic bonding skeleton, the synergistic inhibition effect of the components on defect propagation was no longer complete, which made it easier for local stress to accumulate within a limited range and induce chain damage. After entering the bending load and high-speed rotation conditions, the material system changed from the original progressive response state to a state that was more sensitive to the initial defects, and the overall coordination was correspondingly weakened. Ultimately, it is demonstrated that the functional units within the composite grinding wheel are not isolated and parallel to each other, but rather jointly participate in the continuous shaping of the structural state during the formation of the firing configuration, the establishment of the interface transition, and the response during service. When the particle-reinforced configuration is missing, the local support and load transfer path are more likely to become concentrated. When the compositional coordination of the auxiliary glass phase is affected, the spreading, containment, and continuous consolidation processes of the bonding phase change accordingly, and the correspondence between the microstructure uniformity and the interface integrity becomes more difficult to maintain. When the specific morphology of the toughening component is difficult to form, the dispersion, deflection, and slow release links in the defect evolution process tend to weaken. As a result, the skeleton support, bonding connection, and damage control relationships established by the material system at different stages are no longer consistent, and there is a significant linkage between the microstructure after firing and the response mode under subsequent loading, erosion, and high-speed rotation conditions.

[0058] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0059] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A composite grinding wheel based on ceramic materials, characterized in that, The composite grinding wheel is a composite grinding wheel with an alumina matrix as the continuous phase, a particle-reinforcing phase and a whisker-toughening phase dispersed therein, and an auxiliary glass phase distributed among the components. The particle-reinforcing phase is yttrium-stabilized zirconia particles with an aluminum phosphate coating on their surface. The whisker toughening phase is an aluminoborate whisker bundle with a silica anchoring layer on the surface and at the nodes. The auxiliary glass phase is an oxyfluoroborosilicate auxiliary glass powder containing bismuth, zinc, fluorine, boron and silicon structural units.

2. The composite grinding wheel based on ceramic materials according to claim 1, characterized in that, The auxiliary glass phase is prepared by adding bismuth trioxide, zinc fluoride, silicon dioxide and boric acid into a mixer and stirring until uniformly mixed. The mixture is then transferred to a crucible, and the crucible is placed in a high-temperature furnace and heated to 780-810℃. The temperature is maintained for 25-35 minutes, and the auxiliary glass phase is obtained after post-treatment.

3. The composite grinding wheel based on ceramic materials according to claim 2, characterized in that, In the preparation of the auxiliary glass phase, the molar ratio of bismuth trioxide, zinc fluoride, silicon dioxide and boric acid is 1:1.2-1.5:1.6-2.0:2.0-2.

5.

4. The composite grinding wheel based on ceramic materials according to claim 1, characterized in that, The particulate-reinforced phase was prepared by the following method: A1. Add deionized water, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and urea to the reaction vessel and stir. After mixing evenly, heat the reaction vessel to 185-195℃ and keep it at that temperature for 8-12 hours. Post-processing yields yttrium-stabilized zirconium oxide ceramic nucleus powder. A2. Add anhydrous ethanol, deionized water and yttrium-stabilized zirconia ceramic nuclei powder to the reactor and stir. After the mixture is evenly dispersed, add aluminum nitrate nonahydrate and continue stirring until evenly dispersed. Then add 85wt% phosphoric acid and heat the reactor to 165-175℃. Keep the temperature for 5-7 hours. The post-treatment yields the particle-reinforced phase.

5. A composite grinding wheel based on ceramic materials according to claim 4, characterized in that, In step A1, the molar ratio of zirconium oxychloride octahydrate, yttrium nitrate hexahydrate, and urea is 1:0.048-0.058:4.8-6.2, and the amount of deionized water added is 11-14 mL / g based on zirconium oxychloride octahydrate.

6. A composite grinding wheel based on ceramic materials according to claim 4, characterized in that, In step A2, the ratio of yttrium-stabilized zirconia ceramic nucleus powder to aluminum nitrate nonahydrate is 1g:0.48-0.60g, and the amounts of anhydrous ethanol, deionized water, and 85wt% phosphoric acid added are based on yttrium-stabilized zirconia ceramic nucleus powder, and are 6.5-9.8mL / g, 2.4-3.7mL / g, and 0.08-0.13mL / g, respectively.

7. A composite grinding wheel based on ceramic materials according to claim 1, characterized in that, The preparation method of the whisker toughening phase is as follows: alumina, boric acid, silicon dioxide and anhydrous sodium sulfate are added to a mixer and stirred evenly, then transferred to a crucible, and the crucible is placed in a high-temperature furnace and heated to 1020-1060℃ and held for 2.5-3.5h. The whisker toughening phase is obtained by post-treatment.

8. A composite grinding wheel based on ceramic materials according to claim 7, characterized in that, In the process of preparing the whisker toughening phase, the molar ratio of alumina, boric acid and silicon dioxide is 1:0.42-0.47:0.10-0.15, and the amount of anhydrous sodium sulfate added is 4.0-5.5 g / g based on alumina.

9. A method for preparing a composite grinding wheel based on ceramic materials as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Weigh 200-240 parts of deionized water and 16-20 parts of polyvinyl alcohol by weight and add them to a mixing tank. Heat and stir until the polyvinyl alcohol is completely dissolved. Then cool down and add 1.6-2.2 parts of boric acid and stir evenly. Then add 720-840 parts of alumina, 80-100 parts of particle reinforcing phase, 26-34 parts of whisker toughening phase and 63-77 parts of auxiliary glass phase in sequence. Mix evenly and granulate. After post-treatment, alumina-based composite grinding wheel granules are obtained. S2. Add alumina-based composite grinding wheel granules into a mold and press them into shape. After demolding, transfer the molded blank to a sintering furnace and heat it to a set temperature for firing. After firing, cool it to room temperature with the furnace and trim the product to obtain a composite grinding wheel.

10. The method for preparing a composite grinding wheel based on ceramic materials according to claim 9, characterized in that, In step S2, the pressing pressure is 110-130 MPa, and the holding time is 20-40 s; The programmed heating process includes: heating at 1.5-2.5℃ / min to 280-320℃ and holding for 0.8-1.2h, then heating at 1.5-2.5℃ / min to 480-520℃ and holding for 0.8-1.2h, followed by heating at 2.5-3.5℃ / min to 870-890℃ and holding for 1.5-2.5h.

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