Wear-resistant high-strength ceramic-based grinding wheel and preparation method thereof

Abstract

The application discloses a wear-resistant high-strength ceramic-based grinding wheel and a preparation method thereof, and belongs to the technical field of abrasive preparation, and is used for solving the technical problem that the mechanical strength and thermal shock resistance of the ceramic-based grinding wheel in the prior art need to be further improved. The magnesium-aluminum-silicon binder, the spinel reinforcing material and the calcium aluminate toughening material are prepared and are applied in the ceramic-based grinding wheel system in cooperation, so that the composite structure with the functions of binding, reinforcing and toughening is constructed. The magnesium-aluminum-silicon binder is used for forming a stable and continuous binding phase, the spinel reinforcing material is used for improving the stability of the system framework, and the calcium aluminate toughening material is used for improving the interface transition and relieving local stress concentration, so that the ceramic-based grinding wheel has a more coordinated organizational structure and a more optimal comprehensive use effect.

Description

Technical Field

[0001] This invention relates to the field of abrasive preparation technology, specifically to a wear-resistant, high-strength ceramic-based grinding wheel and its preparation method. Background Technology

[0002] In existing technologies, wear-resistant high-strength grinding wheels mostly use abrasives such as corundum and silicon carbide as the working phase, and are made with ceramic binders, resin binders, or metal binders. Among them, ceramic-based grinding wheels are widely used in the precision grinding of alloys, ceramics, hard and brittle materials, and high-hardness metal components due to their good heat resistance, high dimensional stability, and good shape retention. Related technologies usually adjust the strength, wear resistance, sharpness, and service life of the grinding wheel by adjusting the binder composition, abrasive particle size distribution, pore structure, and sintering process, so as to meet the requirements of grinding efficiency and surface quality in different processing scenarios.

[0003] However, in the pursuit of high strength and high wear resistance, existing ceramic-based grinding wheels often focus more on the densification and hardening effect of the bonding phase, which can easily lead to excessively high local rigidity in the bonding bridge area and insufficient structural coordination between abrasive grains, bonding phase, and pores. When the grinding wheel is used under high-speed grinding and intermittent contact conditions, local loads and thermal stresses tend to concentrate in the bonding bridge and the area around the abrasive grains, which can lead to the initiation, propagation, and local spalling of microcracks. This not only affects the stability of abrasive grain holding but also makes it difficult to balance wear resistance and damage resistance during the use of the grinding wheel.

[0004] Furthermore, some existing technologies lack effective synergistic design among binders, reinforcing components, and functional fillers. It is difficult to balance the uniformity of distribution of different components at the microscale and the interfacial transition state, which can easily lead to local segregation, insufficient interphase bonding, or mismatch in thermal response. Under these conditions, the internal stress transmission path of the grinding wheel is discontinuous after being subjected to force, and the crack deflection, passivation, and energy dissipation capabilities are limited. As a result, while maintaining high strength, the impact resistance, thermal shock resistance, and long-term service stability of the product still have room for improvement. This is also a technical problem that urgently needs to be solved in the existing technology.

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

[0006] The purpose of this invention is to provide a wear-resistant, high-strength ceramic-based grinding wheel and its preparation method, which solves the technical problem that the mechanical strength and thermal shock resistance of ceramic-based 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 method for preparing a wear-resistant, high-strength ceramic-based grinding wheel includes the following steps: Step 1: Mix silicon source, magnesium source, aluminum source, organic complexing agent and organic solvent with water, perform sol-gel treatment, and then dry, heat treat and pulverize to obtain magnesium-aluminum-silicon binder; Step 2: Mix the magnesium source, zinc source, nickel source, aluminum source and fuel agent, and then concentrate, combust and heat treat to obtain spinel reinforced material; Step 3: Mix the calcium source, aluminum source and molten salt, carry out a high-temperature reaction, and then wash, dry and sieve to obtain calcium aluminate toughening material; Step 4: Mix the alumina abrasive, the magnesium aluminum silicon binder, the spinel reinforcement, and the calcium aluminate toughening agent with the molding aid, and then granulate, press, and sinter to obtain a ceramic-based grinding wheel.

[0008] Furthermore, the preparation method of the magnesium-aluminum-silicon binder is as follows: anhydrous ethanol and deionized water are added to a reaction vessel and stirred until uniformly mixed. Then, tetraethyl orthosilicate is added and stirred until uniformly mixed. Citric acid and ethylene glycol are added, followed by magnesium nitrate hexahydrate. After stirring until completely dissolved, aluminum isopropanol is added. The reaction vessel is heated to 75-82°C and stirred for 40-60 minutes. Then, the temperature is raised to 86-92°C and stirred for 2-3 hours. The mixture is then poured into a tray and allowed to stand for 6-8 hours to obtain a gel block. After heat treatment, the magnesium-aluminum-silicon binder is obtained.

[0009] Furthermore, in the process of preparing the magnesium-aluminum-silicon binder, the ratio of anhydrous ethanol, deionized water, tetraethyl orthosilicate, citric acid, ethylene glycol, magnesium nitrate hexahydrate, and aluminum isopropanol is 400-520mL:105-140mL:110-130mL:80-105g:48-60mL:60-80g:95-125g.

[0010] Furthermore, the heat treatment includes: drying the gel block in a drying oven at 105-115℃ for 6-8 hours, then heating it to 620-680℃ at 1.5-2.5℃ / min and holding it at that temperature for 0.8-1.2 hours in an air atmosphere, followed by heating it to 1080-1120℃ at 2.5-3.5℃ / min and holding it at that temperature for 1.5-2.5 hours, cooling it, pulverizing it, and passing it through a 200-300 mesh sieve to obtain a magnesium-aluminum-silicon binder.

[0011] Furthermore, the preparation method of the spinel reinforcement is as follows: deionized water is added to a reaction vessel and stirred, then magnesium nitrate hexahydrate, zinc nitrate hexahydrate, nickel nitrate hexahydrate and aluminum nitrate nonahydrate are added in sequence and stirred until completely dissolved. Glycine is then added and stirred until homogeneous. The reaction vessel is then heated to 85-90℃ for concentration, and the solid content of the system is controlled to be 58-62wt%. The temperature is maintained for 20-25 minutes, then the temperature is raised to 250-270℃ and maintained for 10-12 minutes to obtain a loose precursor. The spinel reinforcement is then obtained through post-processing.

[0012] Furthermore, in the preparation of spinel reinforcement, the ratio of deionized water, magnesium nitrate hexahydrate, zinc nitrate hexahydrate, nickel nitrate hexahydrate, aluminum nitrate nonahydrate, and glycine is 180-230mL:12-15g:6-8g:7-9g:68-82g:27-33g. The post-treatment includes: transferring the loose precursor into a muffle furnace and holding it at 880-930℃ for 0.5-1.0h; allowing the calcined solid to cool naturally to room temperature; and grinding it through a 200-300 mesh sieve to obtain spinel reinforcement.

[0013] Furthermore, the preparation method of the calcium aluminate toughening material is as follows: sodium chloride and potassium chloride are added to a mixer and stirred. After mixing evenly, calcium carbonate and aluminum hydroxide are added. After stirring evenly again, the mixture is transferred to a crucible. The crucible is then placed in a high-temperature furnace and heated to 1160-1210℃. The temperature is maintained for 2-3 hours. The calcium aluminate toughening material is then obtained through post-treatment.

[0014] Furthermore, the ratio of sodium chloride, potassium chloride, calcium carbonate, and aluminum hydroxide is 160-200g:105-135g:4-6g:42-52g. The post-treatment includes: after the heat preservation is completed, cooling the solid with the furnace to below 300℃ and taking it out, transferring the obtained solid to deionized water at 75-85℃ for washing, filtering and collecting the solid, and then placing the solid in a drying oven at 100-110℃ for drying for 5-7 hours. After cooling, the solid is depolymerized and passed through a 150-250 mesh sieve to obtain calcium aluminate toughening material.

[0015] Furthermore, the preparation method of the ceramic-based grinding wheel is as follows: by weight, weigh 200-240 parts of deionized water and 16-20 parts of polyvinyl alcohol and add them to a mixing tank for heating and stirring. After the polyvinyl alcohol is completely dissolved, cool down and add 1.6-2.2 parts of boric acid and stir evenly. Then, add 740-820 parts of alumina, 105-135 parts of magnesium aluminum silicon binder, 32-48 parts of spinel reinforcement and 20-28 parts of calcium aluminate toughening material in sequence. After mixing evenly, granulate and sizing. Then, put the granules into a mold and press them into shape. Then, sinter, cool with the furnace and trim to obtain the ceramic-based grinding wheel.

[0016] Furthermore, in the process of preparing ceramic-based grinding wheels, the granulation operation is as follows: the granulated wet particles are granulated through a 14-18 mesh sieve, and then the particles are dried in a drying oven at 75-85℃ for 3-5 hours. After cooling, they are passed through a 12-20 mesh sieve. The pressing pressure is 110-130MPa, and the holding time is 20-40s. The sintering operation includes: heating to 280-320℃ at 1.5-2.5℃ / min and holding for 0.8-1.2 hours, then heating to 500-540℃ at 1.5-2.5℃ / min and holding for 0.8-1.2 hours, followed by heating to 1100-1140℃ at 2.5-3.5℃ / min and holding for 1.5-2.5 hours.

[0017] The present invention also discloses a wear-resistant high-strength ceramic-based grinding wheel, which is prepared by a method for preparing a wear-resistant high-strength ceramic-based grinding wheel.

[0018] The present invention has the following beneficial effects: The magnesium-aluminum-silicon binder prepared by this invention forms a continuous and relatively evenly distributed binder phase after sintering, and overlaps with relatively complete binder bridges between abrasive grains. Spinel reinforcement is embedded in the binder bridge, providing support for the stress-bearing skeleton. Calcium aluminate toughening material is located in the region adjacent to the binder phase and interface, making the stiffness transition between different phases relatively smooth. During the bending, compressive and grinding loads at room temperature, the load is transmitted from the abrasive grains to the binder bridge and can be gradually dispersed along the continuous binder phase. Local stress is less likely to remain at individual weak joints, and the tendency for interface separation, local crushing and abnormal abrasive grain shedding is correspondingly reduced. Premature wear of the binder bridge is suppressed, and the working layer of the grinding wheel is well maintained. Therefore, the room temperature bending strength and room temperature compressive strength are maintained at a relatively ideal level, which is also beneficial to improving the wear resistance and service stability of ceramic-based grinding wheels.

[0019] After the spinel reinforcement prepared by this invention is dispersed into the matrix composed of magnesium aluminum silicon bonding phase, the interior of the grinding wheel no longer exhibits a single continuous brittle channel. The calcium aluminate toughening material is further configured in the interface transition region, so that the local area can still maintain a relatively mild stress transfer state under the alternating action of thermal and mechanical loads. During operation, when cracks initiate at local defects, the propagation path of the crack in the region adjacent to the spinel phase is more likely to deviate, bifurcate, or detour, and it is difficult to penetrate rapidly along a straight line. Under alternating hot and cold conditions, the continuous bonding phase and the interface buffer region cooperate with each other, the thermal stress accumulation rate is suppressed, and microcracks are not easy to connect quickly. Therefore, the fracture toughness and the retention rate of bending strength after thermal shock are in a better state.

[0020] The calcium aluminate toughening material prepared by this invention, after being distributed in the bonding bridge and the adjacent area of ​​the interface, continuously regulates the microcrack tip and local fragile parts under high-speed rotation conditions; the magnesium-aluminum-silicon bonding material maintains the continuity of the bonding structure, so that the disturbance of the overall stress field by discrete defects inside the wheel body is not significantly amplified; the spinel reinforcement material maintains the local support capacity of the bonding bridge during the continuous increase of centrifugal load. As the rotation speed increases, the stress inside the wheel body can be transmitted more evenly among the multiphase structures. Although local damage may gradually appear, it is not easy to quickly evolve into through instability. The microcrack connection process is relatively delayed. The whole wheel still maintains good structural integrity and running stability under high linear speed, and the fracture linear velocity is also at a correspondingly high level. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a SEM image of the magnesium-aluminum-silicon binder prepared in Example 3 of the present invention; Figure 2 This is a SEM image of the spinel reinforcement material prepared in Example 3 of the present invention; Figure 3 This is a SEM image of the calcium aluminate toughening material prepared in Example 3 of the present invention. Detailed Implementation

[0023] 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.

[0024] In this application, the alumina used was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., with item number A664978.

[0025] Example 1

[0026] This embodiment provides a method for preparing a wear-resistant, high-strength ceramic-based grinding wheel, including the following steps: Step 1: Preparation of magnesium-aluminum-silicon binder Weigh out 400.0 mL of anhydrous ethanol and 105.0 mL of deionized water and add them to the reaction vessel. Stir until the mixture is homogeneous, then add 110.0 mL of tetraethyl orthosilicate and continue stirring until homogeneous. Add 80.0 g of citric acid and 48.0 mL of ethylene glycol, then add 60.0 g of magnesium nitrate hexahydrate and stir until completely dissolved. Add 95.0 g of aluminum isopropanol and heat the reaction vessel to 75°C. Keep the temperature and stir for 40 min, then heat to 86°C and keep the temperature and stir for 2 h. Pour the mixture into a tray and let it stand for 6 h to obtain a gel block. Place the gel block in a drying oven at 105°C and dry for 6 h. Then place it in an air atmosphere and heat it to 620°C at 1.5°C / min and keep it at 0.8 h. Then heat it to 1080°C at 2.5°C / min and keep it at 1.5 h. After cooling, pulverize and pass it through a 200-mesh sieve to obtain a magnesium-aluminum-silicon binder.

[0027] The reaction principle for preparing magnesium-aluminum-silicon binders is as follows: Tetraethyl orthosilicate undergoes hydrolysis and condensation in an ethanol-water system, forming an inorganic polymer network with silicon-oxygen bonds as the basic framework. Citric acid and ethylene glycol form an organic complex system, in which citric acid coordinates magnesium ions and aluminum-containing species formed by the hydrolysis of aluminum sources, while ethylene glycol participates in the esterification reaction and regulates the dispersion state of each component in the system. Magnesium nitrate hexahydrate provides the magnesium component, and aluminum isopropanol introduces the aluminum component through alcoholysis and hydrolysis, so that magnesium, aluminum, and silicon components enter the gel network together. During the drying process, the system completes the transformation from sol to gel. Subsequent heat treatment corresponds to the removal of organic components, decomposition of nitrate ions, and further condensation and rearrangement of the inorganic framework, finally yielding a magnesium-aluminum-silicon bound material.

[0028] The mechanism of action of magnesium-aluminum-silicon binders in ceramic-based grinding wheels is as follows: The impact of this process on the final magnesium-aluminum-silicon binder is mainly reflected in its combined shaping of structural origin, elemental distribution, and network integrity. The silicon source constitutes the primary source of the inorganic framework of the binder, determining the continuity of the basic network. After magnesium and aluminum components enter this framework, they regulate the local coordination environment, network connectivity, and the formation of thermally stable structural units, transforming the final product from a single siliceous structure into a more harmonious magnesium-aluminum-silicon composite structure. Although citric acid and ethylene glycol do not constitute the final inorganic matrix, they play a crucial role in the uniform embedding of multi-component components in the precursor, thereby reducing local segregation and structural abruptness. The gel and drying intermediates further support and solidify the aforementioned distribution characteristics, allowing them to be inherited in subsequent powders. Therefore, the resulting magnesium-aluminum-silicon binder typically exhibits good compositional uniformity, particle coordination, and a solid foundation for subsequent phase construction.

[0029] Step 2: Preparation of spinel reinforcement material Weigh 180.0 mL of deionized water and add it to the reactor and stir. Then, add 12.0 g of magnesium nitrate hexahydrate, 6.0 g of zinc nitrate hexahydrate, 7.0 g of nickel nitrate hexahydrate, and 68.0 g of aluminum nitrate nonahydrate in sequence. Stir until completely dissolved, then add 27.0 g of glycine and continue stirring until homogeneous. Then, heat the reactor to 85°C for concentration, control the solid content of the system to 58 wt%, and keep it at this temperature for 20 min. Then, heat the reactor to 250°C and keep it at this temperature for 10 min to obtain a loose precursor. Transfer the loose precursor to a muffle furnace and keep it at 880°C for 0.5 h. Let the calcined solid cool naturally to room temperature, grind it through a 200-mesh sieve, and obtain spinel reinforcement material.

[0030] The reaction principle for preparing spinel reinforcement is as follows: Magnesium nitrate, zinc nitrate, nickel nitrate, and aluminum nitrate dissociate in the aqueous phase to form corresponding metal ions. Glycine coordinates with various metal ions via its amino and carboxyl groups to form a multi-metal complex system. As moisture decreases and temperature increases, the distribution between metal salts and organic ligands becomes more concentrated, and the system transforms into a composite precursor containing magnesium, zinc, nickel, and aluminum. In this system, nitrate acts as an oxidizing component, and glycine acts as a reducing organic ligand. Upon heating, they undergo redox decomposition and release gases, forming a loose solid product. During subsequent calcination, the metal oxides undergo further solid-phase reactions and crystal structure rearrangement to form spinel reinforcement.

[0031] The mechanism of action of spinel reinforcement in ceramic-based grinding wheels is as follows: In this process, the effects of various metal salts, glycine, and porous precursors on the final spinel reinforcement are mainly reflected in their joint shaping of the source of its cation composition, the uniformity of its microscopic distribution, and the integrity of its crystal structure. Among them, magnesium, zinc, nickel, and aluminum components together constitute the source of metal cations in the spinel lattice. The synergistic introduction of different metal ions makes the final product different from a single aluminate or magnesium-aluminum system, and it is easier to form a spinel phase with complex composition and diverse local structures. Although glycine is not retained as the final inorganic host, it plays an important role in the uniform embedding and fine-scale mixing of multi-metal components in the precursor, thereby reducing the tendency of local segregation and coarse phase separation. The porous precursor further inherits and solidifies the above distribution state, making the powder obtained after calcination more coordinated in terms of particle size, phase composition, and degree of crystal formation. As a result, the obtained spinel reinforcement usually has good compositional uniformity, structural stability, and serves as a basis for participating in the construction of subsequent systems as a reinforcing unit.

[0032] Step 3: Preparation of calcium aluminate toughening material Weigh out 160.0g of sodium chloride and 105.0g of potassium chloride and add them to a mixer. After mixing evenly, add 4.0g of calcium carbonate and 42.0g of aluminum hydroxide. Continue mixing evenly and transfer the mixture to a crucible. Place the crucible in a high-temperature furnace and heat it to 1160℃. Hold the temperature for 2 hours. After holding the temperature, cool it to below 300℃ with the furnace and remove it. Transfer the obtained solid to 75℃ deionized water for washing. Filter and collect the solid. Place the solid in a drying oven at 100℃ and dry it for 5 hours. After cooling, depolymerize and pass it through a 150-mesh sieve to obtain calcium aluminate toughening material.

[0033] The reaction principle for preparing calcium aluminate toughening material is as follows: Sodium chloride and potassium chloride form a high-temperature molten salt medium in this system, providing a liquid-phase mass transfer environment for the calcium and aluminum sources. Calcium carbonate decomposes upon heating to release carbon dioxide and generate calcium oxide. Aluminum hydroxide is dehydrated and converted into aluminum oxide. The two react in the molten salt environment through solid-liquid coupling to complete the chemical combination between the calcium and aluminum components and generate calcium aluminate. The molten salt is not a component of the target product. The water washing process is used to remove residual sodium chloride, potassium chloride and other soluble substances. After separation and drying, calcium aluminate toughening material is obtained.

[0034] The mechanism of action of calcium aluminate toughening material in ceramic-based grinding wheels is as follows: The influence of raw materials and salt bath environment on the final calcium aluminate toughening material in this process is mainly reflected in the joint shaping of its phase composition, particle morphology, and interfacial activity. Among them, the calcium and aluminum sources together constitute the composition of the calcium aluminate phase, determining the calcium-aluminum ratio, the degree of crystal phase formation, and local structural characteristics in the final product. Although the molten salt system does not enter the final inorganic matrix, it has a significant impact on the contact state of reactants, particle growth mode, and uniformity of structural distribution, making it easier for calcium and aluminum components to achieve uniform bonding at a smaller scale, reducing the tendency of coarse agglomeration and the formation of local unreacted areas. The solid structure retained after washing and drying further reflects a relatively clean particle surface and a relatively independent particle state. As a result, the obtained calcium aluminate toughening material usually has good phase composition coordination, particle dispersion, and interfacial transition potential, which is more conducive to mitigating local stress concentration and participating in the construction of toughening structure in subsequent systems.

[0035] Step 4: Preparation of ceramic-based grinding wheels Weigh out 200.0 parts by weight of deionized water and 16.0 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. Subsequently, add 740.0 parts by weight of alumina, 105.0 parts by weight of magnesium aluminum silicon binder, 32.0 parts by weight of spinel reinforcement and 20.0 parts by weight of calcium aluminate toughening material. Mix evenly and granulate. Sieve the granulated wet granules through a 14-mesh sieve. Then place the granules in a drying oven at 75°C for 3 hours. After cooling, sieve through a 12-mesh sieve. The granules are added to a mold and pressed into shape. The ceramic-based grinding wheel is a flat ceramic-based grinding wheel with an outer diameter of 300.0 mm, a thickness of 40.0 mm, and a center hole diameter of 127.0 mm. The pressing pressure is 110 MPa, and the holding time is 20 s. Then, the temperature is increased to 280℃ at 1.5℃ / min and held for 0.8 h. Then, the temperature is increased to 500℃ at 1.5℃ / min and held for 0.8 h. Then, the temperature is increased to 1100℃ at 2.5℃ / min and held for 1.5 h. The wheel is cooled in the furnace and trimmed to obtain the ceramic-based grinding wheel.

[0036] The reaction principle for preparing ceramic-based grinding wheels is as follows: Polyvinyl alcohol forms an organic binder system in water. Boric acid complexes with the hydroxyl groups on the polyvinyl alcohol molecular chain to form a cross-linked structure, ensuring that alumina, magnesium aluminum silicon binder, spinel reinforcement, and calcium aluminate toughening agent are uniformly distributed in the mixed system. After pressing, each particle forms a stable green body under external force. During the heating process, the system successively undergoes moisture removal, thermal decomposition of organic binder components, and contact strengthening between inorganic particles. Under firing conditions, a continuous ceramic bond structure is formed between the inorganic components, ultimately yielding a ceramic-based grinding wheel.

[0037] Example 2

[0038] This embodiment provides a method for preparing a wear-resistant, high-strength ceramic-based grinding wheel, including the following steps: Step 1: Preparation of magnesium-aluminum-silicon binder Weigh out 460.0 mL of anhydrous ethanol and 122.5 mL of deionized water and add them to the reaction vessel. Stir until the mixture is homogeneous, then add 120.0 mL of tetraethyl orthosilicate and continue stirring until homogeneous. Add 92.5 g of citric acid and 54.0 mL of ethylene glycol, then add 70.0 g of magnesium nitrate hexahydrate and stir until completely dissolved. Add 110.0 g of aluminum isopropanol and heat the reaction vessel to 78.5 °C. Keep the temperature and stir for 50 min, then heat to 89 °C and keep the temperature and stir for 2.5 h. Pour the mixture into a tray and let it stand for 7 h to obtain a gel block. Place the gel block in a drying oven at 110 °C and dry for 7 h. Then place it in an air atmosphere and heat it to 650 °C at 2.0 °C / min and keep it at 1.0 h. Then heat it to 1100 °C at 3.0 °C / min and keep it at 2.0 h. After cooling, pulverize and pass it through a 250 mesh sieve to obtain a magnesium-aluminum-silicon binder.

[0039] Step 2: Preparation of spinel reinforcement material Weigh 205.0 mL of deionized water and add it to the reactor. Stir, then add 13.5 g of magnesium nitrate hexahydrate, 7.0 g of zinc nitrate hexahydrate, 8.0 g of nickel nitrate hexahydrate, and 75.0 g of aluminum nitrate nonahydrate in sequence. Stir until completely dissolved, then add 30.0 g of glycine and continue stirring until homogeneous. Then heat the reactor to 87.5 °C for concentration, control the solid content of the system to 60 wt%, and hold for 22.5 min. Then heat to 260 °C and hold for 11 min to obtain a loose precursor. Transfer the loose precursor to a muffle furnace and hold at 905 °C for 0.8 h. Let the calcined solid cool naturally to room temperature, grind it through a 250 mesh sieve, and obtain spinel reinforcement material.

[0040] Step 3: Preparation of calcium aluminate toughening material Weigh out 180.0g of sodium chloride and 120.0g of potassium chloride and add them to a mixer. After mixing evenly, add 5.0g of calcium carbonate and 47.0g of aluminum hydroxide and continue mixing evenly. Transfer the mixture to a crucible and place it in a high-temperature furnace. Heat the crucible to 1185℃ and hold it at that temperature for 2.5h. After holding, cool it to below 300℃ with the furnace and remove it. Transfer the obtained solid to 80℃ deionized water for washing. Filter and collect the solid. Place the solid in a drying oven at 105℃ and dry it for 6h. After cooling, depolymerize and pass it through a 200-mesh sieve to obtain calcium aluminate toughening material.

[0041] Step 4: Preparation of ceramic-based grinding wheels Weigh out 220.0 parts by weight of deionized water and 18.0 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. Subsequently, add 780.0 parts by weight of alumina, 120.0 parts by weight of magnesium aluminum silicon binder, 40.0 parts by weight of spinel reinforcement and 24.0 parts by weight of calcium aluminate toughening material. Mix evenly and granulate. Sieve the granulated wet granules through a 16-mesh sieve. Then place the granules in a drying oven at 80°C for 4 hours. After cooling, sieve through a 16-mesh sieve. The granules are added to a mold and pressed into shape. The ceramic-based grinding wheel is a flat ceramic-based grinding wheel with an outer diameter of 300.0 mm, a thickness of 40.0 mm, and a center hole diameter of 127.0 mm. The pressing pressure is 120 MPa, and the holding time is 30 s. Then, the temperature is increased to 300℃ at 2.0℃ / min and held for 1.0 h. Then, the temperature is increased to 520℃ at 2.0℃ / min and held for 1.0 h. Then, the temperature is increased to 1120℃ at 3.0℃ / min and held for 2.0 h. The wheel is cooled in the furnace and trimmed to obtain the ceramic-based grinding wheel.

[0042] Example 3

[0043] This embodiment provides a method for preparing a wear-resistant, high-strength ceramic-based grinding wheel, including the following steps: Step 1: Preparation of magnesium-aluminum-silicon binder Weigh out 520.0 mL of anhydrous ethanol and 140.0 mL of deionized water and add them to the reaction vessel. Stir until well mixed, then add 130.0 mL of tetraethyl orthosilicate and continue stirring until well mixed. Add 105.0 g of citric acid and 60.0 mL of ethylene glycol, then add 80.0 g of magnesium nitrate hexahydrate and stir until completely dissolved. Add 125.0 g of aluminum isopropanol and heat the reaction vessel to 82°C. Keep the temperature and stir for 60 min, then heat to 92°C and keep the temperature and stir for 3 h. Pour the mixture into a tray and let it stand for 8 h to obtain a gel block. Place the gel block in a drying oven at 115°C and dry for 8 h. Then place it in an air atmosphere and heat it to 680°C at 2.5°C / min and keep it at 1.2 h. Then heat it to 1120°C at 3.5°C / min and keep it at 2.5 h. After cooling, pulverize and pass it through a 300-mesh sieve to obtain magnesium-aluminum-silicon binder.

[0044] Step 2: Preparation of spinel reinforcement material Weigh 230.0 mL of deionized water and add it to the reactor. Stir, then add 15.0 g of magnesium nitrate hexahydrate, 8.0 g of zinc nitrate hexahydrate, 9.0 g of nickel nitrate hexahydrate, and 82.0 g of aluminum nitrate nonahydrate in sequence. Stir until completely dissolved, then add 33.0 g of glycine and continue stirring until homogeneous. Then heat the reactor to 90 °C for concentration, control the solid content of the system to 62 wt%, and hold for 25 min. Then heat to 270 °C and hold for 12 min to obtain a loose precursor. Transfer the loose precursor to a muffle furnace and hold at 930 °C for 1.0 h. Let the calcined solid cool naturally to room temperature, grind it through a 300 mesh sieve, and obtain spinel reinforcement material.

[0045] Step 3: Preparation of calcium aluminate toughening material Weigh out 200.0g of sodium chloride and 135.0g of potassium chloride and add them to a mixer. After mixing evenly, add 6.0g of calcium carbonate and 52.0g of aluminum hydroxide and continue mixing evenly. Transfer the mixture to a crucible and place it in a high-temperature furnace. Heat the crucible to 1210℃ and keep it at that temperature for 3 hours. After the holding time is over, cool it down to below 300℃ with the furnace and remove it. Transfer the obtained solid to deionized water at 85℃ and wash it. Filter and collect the solid. Place the solid in a drying oven at 110℃ and dry it for 7 hours. After cooling, depolymerize and pass it through a 250-mesh sieve to obtain calcium aluminate toughening material.

[0046] Step 4: Preparation of ceramic-based grinding wheels Weigh out 240.0 parts by weight of deionized water and 20.0 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. Subsequently, add 820.0 parts by weight of alumina, 135.0 parts by weight of magnesium aluminum silicon binder, 48.0 parts by weight of spinel reinforcement and 28.0 parts by weight of calcium aluminate toughening material. Mix evenly and granulate. Sieve the granulated wet granules through an 18-mesh sieve. Then place the granules in a drying oven at 85°C for 5 hours. After cooling, sieve through a 20-mesh sieve. The granules are added to a mold and pressed into shape. The ceramic-based grinding wheel is a flat ceramic-based grinding wheel with an outer diameter of 300.0 mm, a thickness of 40.0 mm, and a center hole diameter of 127.0 mm. The pressing pressure is 130 MPa, and the holding time is 40 s. Then, the temperature is increased to 320℃ at 2.5℃ / min and held for 1.2 h. Then, the temperature is increased to 540℃ at 2.5℃ / min and held for 1.2 h. Then, the temperature is increased to 1140℃ at 3.5℃ / min and held for 2.5 h. The wheel is cooled in the furnace and trimmed to obtain the ceramic-based grinding wheel.

[0047] Comparative Example 1 The difference between this comparative example and Example 3 is that the magnesium-aluminum-silicon binder is omitted in step four.

[0048] Comparative Example 2 The difference between this comparative example and Example 3 is that the spinel reinforcement material is omitted in step four.

[0049] Comparative Example 3 The difference between this comparative example and Example 3 is that the use of calcium aluminate toughening material is omitted in step four.

[0050] Performance testing: The room temperature bending strength was determined according to GB / T 1965-2023 "Test Method for Room Temperature Bending Strength of Porous Ceramics". The test result is expressed as room temperature bending strength in MPa. The commonly used four-point bending fixture has an outer span length of 60 mm and an inner span length of 30 mm. The specific test parameters are as follows: Strip-shaped specimens were cut from the annular working area of ​​the ceramic-based grinding wheels prepared in Examples 1-3 and Comparative Examples 1-3. The specimen size was uniformly 75.0mm×10.0mm×8.0mm. An electronic universal testing machine with a four-point bending fixture was used, with the outer span length fixed at 60.0mm and the inner span length fixed at 30.0mm. The load was applied using a displacement control method, with the beam speed fixed at 0.5mm / min. Ten valid specimens were taken from each group, the maximum fracture load was recorded, and the room temperature bending strength was calculated according to the standard. The arithmetic mean of the results was taken.

[0051] The room temperature compressive strength was determined according to GB / T 1964-2023 "Test Method for Room Temperature Compressive Strength of Porous Ceramics". The test results are expressed as room temperature compressive strength, and the unit is MPa. The specific test parameters are as follows: block-shaped samples were cut from the ceramic-based grinding wheels prepared in Examples 1-3 and Comparative Examples 1-3. The sample size was uniformly 10.0mm×10.0mm×10.0mm. The two pressure-bearing end faces were lightly ground with 600-grit silicon carbide sandpaper until they were flat and parallel to each other. An electronic universal testing machine was used, with the indenter end face coaxially aligned with the pressure-bearing surface of the sample. The loading was carried out using a displacement control method, and the beam speed was fixed at 0.5mm / min. Ten effective samples were taken from each group, the maximum crushing load was recorded, and the room temperature compressive strength was calculated according to the standard. The results were taken as the arithmetic mean.

[0052] Wear resistance was determined by constant-condition grinding tests, and the test results were expressed as the grinding ratio, which is the ratio of the workpiece volume removed to the grinding wheel wear volume. Specific test parameters are as follows: Ceramic-based grinding wheels prepared in Examples 1-3 and Comparative Examples 1-3 were selected as test samples and mounted on the spindle of a surface grinder. Each group of grinding wheels was dressed under the same dressing conditions. 45 steel test blocks were selected as the workpieces to be ground, with uniform dimensions of 50.0mm × 20.0mm × 10.0mm. During grinding, the grinding wheel linear velocity was fixed at 30m / s, the workpiece feed rate was fixed at 0.2m / min, and the single grinding depth was fixed at 20μm. Wet grinding was performed continuously. Three valid samples were taken from each group, and the workpiece mass and grinding wheel mass before and after grinding were recorded. The workpiece volume removed and the grinding wheel wear volume were calculated based on their respective densities. The grinding ratio was calculated as Vw / Vs, where Vw represents the workpiece volume removed and Vs represents the grinding wheel wear volume.

[0053] The flexural strength retention rate after thermal shock was determined according to GB / T 37246-2018 "Test Method for Thermal Shock Resistance of Fine Ceramics". The test result is expressed as the flexural strength retention rate after thermal shock, in percentage (%). The specific test parameters are as follows: Strip-shaped samples were cut from the annular working area of ​​the ceramic-based grinding wheels prepared in Examples 1-3 and Comparative Examples 1-3. The sample size was uniformly 75.0mm×10.0mm×8.0mm. The samples were placed in a box furnace and heated to 350±2℃ at 10℃ / min. After holding at this temperature for 30min, the samples were transferred to deionized water at 25±2℃ within 2s for a water-cooled thermal shock. After removal, the samples were naturally dried for 2h, and the remaining bending strength was determined according to the same parameters as in GB / T 1965-2023. The ratio of the remaining bending strength after thermal shock to the room temperature bending strength before thermal shock was multiplied by 100% to obtain the bending strength retention rate after thermal shock. Ten valid samples were taken from each group, and the results were taken as the arithmetic mean.

[0054] The rotational strength was determined according to GB / T 2493-2023 "Test Method for Rotational Strength of Abrasives". The test result is expressed as the fracture line velocity in m / s. The standard clearly stipulates the accuracy and installation method of the rotational testing machine, including that the relative error of the spindle speed is ±1.0%, the radial runout of the spindle of the bonded abrasive testing machine is not greater than 0.03mm, and only one abrasive is allowed to be installed at a time during the fracture velocity test. The specific test parameters are as follows: The ceramic-based grinding wheels prepared in Examples 1-3 and Comparative Examples 1-3 were directly tested. The grinding wheel specifications were an outer diameter of 300.0 mm, a thickness of 40.0 mm, and a center hole diameter of 127.0 mm. A bushing matching the φ127.0 mm center hole was used to install the grinding wheel on the spindle of the rotary testing machine. The two ends were clamped with steel chucks and partitions matching the flat grinding wheel. The dimensions of the chuck and partitions were selected according to Appendix A of the standard. Only one grinding wheel was installed at a time. After starting the equipment, the speed was increased uniformly until the grinding wheel broke. The spindle speed at the moment of breakage was recorded, and the breakage linear velocity was calculated according to the outer diameter of the grinding wheel of 300.0 mm. Five whole wheels were taken from each group, and the results were taken as the arithmetic mean.

[0055] See Table 1 for specific data; Table 1 - Performance Test Data for Each Sample Room temperature flexural strength / MPa 52.4 53.1 53.8 41.3 48.0 48.7 Room temperature compressive strength / MPa 126.8 128.2 129.4 101.6 119.0 120.5 Grinding ratio 62.5 64.0 65.3 50.1 53.8 55.8 Flexural strength retention rate after thermal shock / % 76.9 77.8 78.6 63.8 70.6 69.2 <![CDATA[Rupture line speed / m·s -1 > 116.8 118.1 119.3 98.7 106.8 109.1 Data Analysis: Comparative analysis of the data in Table 1 reveals that the ceramic-based grinding wheel prepared in this invention exhibits a room temperature flexural strength of 52.4 MPa, a room temperature compressive strength of 126.8 MPa, a grinding ratio of 65.3, and a flexural strength retention rate of 76.9% after thermal shock, while also having a fracture linear velocity of 116.8 m / s. -1 All data points are better than the comparative data, indicating that: In Comparative Example 1, after step one was deleted, the system lost the effective conditions for constructing a continuous bonding phase and a balanced bonding bridge structure. After firing, it was difficult for the abrasive grains to form a well-distributed and interconnected network. Local areas were more likely to exhibit a discrete connection state. During the load-bearing process, the stress transmission path tended to be shortened and concentrated in a few contact points. Local weak areas were more likely to experience interface loosening, weakening of connections, and microcrack initiation first. Furthermore, due to the lack of continuous support in the internal phase transition, the stress formed under bending, compression, and thermal shock conditions was difficult to disperse gradually over a larger area. Local damage was more likely to change from point accumulation to regional expansion, which in turn caused adverse changes in the sample's load-bearing stability, damage tolerance, and high-speed service compatibility. At the same time, during the grinding process, insufficient bonding bridge integrity would also reduce the stability of abrasive grain holding, increase the tendency for local sand shedding and excessively rapid consumption of the working layer, and thus adversely affect its wear resistance.

[0056] In Comparative Example 2, after step two was removed, the system lost the structural units that reinforced the local skeleton of the bonding bridge and disturbed the crack propagation path. The multiphase support relationship formed after firing was relatively simplified. Under continuous load, the local stress inside the bonding phase is more likely to concentrate along a relatively direct path. After microcracks are initiated, there is a lack of sufficient path dispersion conditions, and the process of cracks transforming from dispersed existence to interconnection is relatively accelerated. At the same time, under alternating hot and cold conditions, the repeated action of thermal stress on local weak areas is more likely to be transformed into continuous damage. The hierarchical hindrance relationship originally formed by multiphase embedding is difficult to fully establish. As a result, the damage evolution inside the sample tends to be more concentrated, the structural maintenance state is more easily disturbed, and the composite service performance decreases accordingly. In addition, due to the weakening of the local support capacity of the bonding bridge, the tendency of local damage and abrasive loosening during grinding increases accordingly, and its wear resistance is lower than that of the example.

[0057] In Comparative Example 3, after step three was removed, the system lost the component configuration that allowed for the transitional adjustment of the bonding phase-abrasive interface and the adjacent region of the reinforcing phase. After sintering, the connection region between different phases was more prone to forming local interfaces with more pronounced stiffness changes. During operation, when the load was transferred from the abrasive to the bonding phase, the local stress in the adjacent region of the interface was not easily adequately relieved, and stress accumulation was more likely to form around the micro-defects. Especially under the combined effects of high-speed rotation and alternating hot and cold, the local high stress state at the microcrack tip was more difficult to delay, the tendency of series damage between small damages was enhanced, and the local brittle region was more likely to evolve into a continuous damage region. As a result, although the sample still maintained a basic shaped structure, the overall damage evolution was faster, and the stability retention ability during service was correspondingly weakened. At the same time, due to insufficient stress buffering in the adjacent region of the interface, the tendency of local erosion and abnormal wear of the bonding phase during grinding would also increase, thus having a certain adverse effect on the wear resistance.

[0058] In conclusion, the functional components in this application are not isolated configurations centered around a single performance index. Instead, they are embedded in the microstructure formed by firing, forming different levels such as continuous construction of the bonding phase, local skeleton stabilization, and interface transition adjustment. These levels form a chain of action that connects the preceding and following stages during subsequent loading, thermal cycling, and high-speed rotation. When any of the aforementioned levels is removed, although the system can still maintain its basic shape and usability, its internal stress transmission path, crack evolution mode, and local damage release rhythm will all undergo identifiable changes. The original synergistic relationship between multiple properties will also tend to weaken. Therefore, this material system is closer to a synergistic configuration relationship with an inherent organizational logic than a conventional combination of several known components linearly superimposed.

[0059] 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.

[0060] 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.

[0061] 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 method for preparing a wear-resistant, high-strength ceramic-based grinding wheel, characterized in that, Includes the following steps: Step 1: Mix silicon source, magnesium source, aluminum source, organic complexing agent and organic solvent with water, perform sol-gel treatment, and then dry, heat treat and pulverize to obtain magnesium-aluminum-silicon binder; Step 2: Mix the magnesium source, zinc source, nickel source, aluminum source and fuel agent, and then concentrate, combust and heat treat to obtain spinel reinforced material; Step 3: Mix the calcium source, aluminum source and molten salt, carry out a high-temperature reaction, and then wash, dry and sieve to obtain calcium aluminate toughening material; Step 4: Mix the alumina abrasive, the magnesium aluminum silicon binder, the spinel reinforcement, and the calcium aluminate toughening agent with the molding aid, and then granulate, press, and sinter to obtain a ceramic-based grinding wheel.

2. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 1, characterized in that, The preparation method of the magnesium-aluminum-silicon binder is as follows: anhydrous ethanol and deionized water are added to a reaction vessel and stirred until uniform. Then, tetraethyl orthosilicate is added and stirred until uniform. Citric acid and ethylene glycol are added, followed by magnesium nitrate hexahydrate. After stirring until completely dissolved, aluminum isopropanol is added. The reaction vessel is heated to 75-82℃ and stirred for 40-60 minutes. Then, the temperature is raised to 86-92℃ and stirred for 2-3 hours. The mixture is then poured into a tray and allowed to stand for 6-8 hours to obtain a gel block. After heat treatment, the magnesium-aluminum-silicon binder is obtained.

3. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 2, characterized in that, In the preparation of magnesium-aluminum-silicon binder, the ratio of anhydrous ethanol, deionized water, tetraethyl orthosilicate, citric acid, ethylene glycol, magnesium nitrate hexahydrate, and aluminum isopropanol is 400-520mL:105-140mL:110-130mL:80-105g:48-60mL:60-80g:95-125g.

4. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 2, characterized in that, The heat treatment includes: drying the gel block in a drying oven at 105-115℃ for 6-8 hours, then heating it to 620-680℃ at 1.5-2.5℃ / min and holding it at that temperature for 0.8-1.2 hours in an air atmosphere, followed by heating it to 1080-1120℃ at 2.5-3.5℃ / min and holding it at that temperature for 1.5-2.5 hours, cooling it, pulverizing it, and passing it through a 200-300 mesh sieve to obtain a magnesium-aluminum-silicon binder.

5. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 1, characterized in that, The preparation method of the spinel reinforcement is as follows: Deionized water is added to a reaction vessel and stirred, followed by the sequential addition of magnesium nitrate hexahydrate, zinc nitrate hexahydrate, nickel nitrate hexahydrate and aluminum nitrate nonahydrate. After stirring until completely dissolved, glycine is added and stirred until homogeneous. The reaction vessel is then heated to 85-90℃ for concentration, controlling the solid content of the system to 58-62wt%, and kept at this temperature for 20-25 minutes. Subsequently, the temperature is raised to 250-270℃ and kept at this temperature for 10-12 minutes to obtain a loose precursor, which is then post-processed to obtain the spinel reinforcement.

6. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 5, characterized in that, In the preparation of spinel reinforcement, the ratio of deionized water, magnesium nitrate hexahydrate, zinc nitrate hexahydrate, nickel nitrate hexahydrate, aluminum nitrate nonahydrate, and glycine is 180-230mL:12-15g:6-8g:7-9g:68-82g:27-33g.

7. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 1, characterized in that, The preparation method of the calcium aluminate toughening material is as follows: sodium chloride and potassium chloride are added to a mixer and stirred. After mixing evenly, calcium carbonate and aluminum hydroxide are added and stirred evenly again. The mixture is then transferred to a crucible and placed in a high-temperature furnace to a temperature of 1160-1210℃. The temperature is maintained for 2-3 hours. The calcium aluminate toughening material is obtained by post-treatment. The ratio of sodium chloride, potassium chloride, calcium carbonate and aluminum hydroxide is 160-200g:105-135g:4-6g:42-52g.

8. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 1, characterized in that, The method for preparing the ceramic-based grinding wheel is as follows: Weigh 200-240 parts of deionized water and 16-20 parts of polyvinyl alcohol by weight, add them to a mixing tank, heat and stir. After the polyvinyl alcohol is completely dissolved, cool down, add 1.6-2.2 parts of boric acid and stir evenly. Then add 740-820 parts of alumina, 105-135 parts of magnesium aluminum silicon binder, 32-48 parts of spinel reinforcement and 20-28 parts of calcium aluminate toughening material in sequence. After mixing evenly, granulate and sizing. Then add the granules into a mold and press them into shape. Then sinter, cool in the furnace and trim to obtain the ceramic-based grinding wheel.

9. The method for preparing a wear-resistant, high-strength ceramic-based grinding wheel according to claim 8, characterized in that, In the process of preparing ceramic-based grinding wheels, the granulation operation is as follows: the wet granulated particles are granulated through a 14-18 mesh sieve, and then the particles are dried in a drying oven at 75-85℃ for 3-5 hours. After cooling, they are passed through a 12-20 mesh sieve. The pressing pressure is 110-130MPa, and the holding time is 20-40s. The sintering operation includes: heating to 280-320℃ at 1.5-2.5℃ / min and holding for 0.8-1.2 hours, then heating to 500-540℃ at 1.5-2.5℃ / min and holding for 0.8-1.2 hours, followed by heating to 1100-1140℃ at 2.5-3.5℃ / min and holding for 1.5-2.5 hours.

10. A wear-resistant, high-strength ceramic-based grinding wheel, characterized in that, The wear-resistant high-strength ceramic-based grinding wheel is prepared using the method described in any one of claims 1-9.

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