Preparation method and application of ceramic cutter head material for ceramic tile cutter

Abstract

The application relates to a preparation method and application of a ceramic cutter head material of a ceramic tile cutter, wherein silicon nitride powder, a sintering aid and a binder are selected as raw materials, are fully wet-mixed through vacuum high-energy ball milling, are dried in a vacuum drying box to obtain carbon-free mixed raw materials, are pre-pressed into a shape, are loaded into a vacuum tube furnace cavity, and are subjected to high-temperature treatment under a vacuum environment through vacuum sintering technology; the carbon-free blank after high-temperature treatment is crushed, a small amount of graphite powder is added, and the carbon-free blank is fully mixed through vacuum low-speed ball milling to obtain carbon-containing mixed raw materials, which are pre-pressed into a shape to obtain a carbon-containing blank; the carbon-containing blank is loaded into a graphite heating cavity, a leaf talc composite block is assembled, and sintering is carried out under high temperature and high pressure through a diamond hydraulic machine to complete the preparation of a beta-Si3N4 sintered body. The beta-Si3N4 sintered body prepared through the method has high strength, good toughness and good wear resistance, is high in operability, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing cutting tool materials for building materials such as ceramic tiles and glass. Specifically, it relates to a method for preparing and applying a high-strength, high-toughness, and wear-resistant silicon nitride ceramic material. Background Technology

[0002] Tile cutters are commonly used tools in the processing of important building materials such as tiles and glass, and the quality of the cutter head determines the processing quality. Currently, the main materials for cutter heads are natural diamond, synthetic diamond, and cemented carbide. Natural diamond and synthetic diamond have extremely high hardness and strength, but natural diamond is very expensive. While synthetic diamond significantly reduces costs, its synthesis requires high precision, with a narrow range of synthesis temperature and pressure, and diamond cutters demand strict operator skills. Cemented carbide has better toughness than diamond, but its hardness and wear resistance are poor, making it prone to wear and resulting in a short service life, and limiting its cutting range. Therefore, selecting the appropriate tile cutter head material is crucial for the processing of building materials.

[0003] Silicon nitride (Si3N4) ceramic materials have attracted widespread attention due to their excellent properties such as high hardness, high strength, corrosion resistance, and good wear resistance. Its hardness and strength are second only to diamond and cubic boron nitride superhard materials, far exceeding those of ceramic tiles and glass. Furthermore, its reserves are abundant and not limited by resources, and its synthesis conditions cover a wide range. If used as a cutting tool material, it could further reduce production costs. However, its toughness is relatively poor compared to cemented carbide, increasing the probability of uneven stress or impact damage during tool machining. Therefore, improving the toughness of the matrix while ensuring the basic properties of silicon nitride has become an important development direction. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing ceramic blade material for tile cutters and its application. This method is highly operable, and the silicon nitride ceramic has high strength, toughness, and wear resistance.

[0005] The technical solution of the present invention:

[0006] A method for preparing a ceramic blade material for a tile cutter, the method comprising the following steps:

[0007] ① Select α-Si3N4 powder, sintering aid powder, and binder powder as raw materials;

[0008] ② The mixed powder raw materials selected in ① above are mixed in a certain proportion, vacuum high-energy ball milled for 1-10 hours to fully wet mix, and then dried in a vacuum drying oven to obtain carbon-free mixed raw materials;

[0009] ③ The carbon-free mixed raw material obtained in ② is pre-pressed into a cylindrical blank and then placed into a vacuum tube furnace cavity. The blank is then subjected to high-temperature treatment in a vacuum environment using vacuum sintering technology.

[0010] ④ The carbon-free green body obtained in ③ after high-temperature treatment is crushed, a small amount of graphite powder is added, and it is thoroughly mixed by vacuum low-speed ball milling to obtain carbon-containing mixed raw material. It is then pre-pressed to obtain a carbon-containing green body.

[0011] ⑤ The carbon-containing preform from ④ is loaded into a graphite heating chamber, pyrophyllite composite blocks are assembled, and sintered under high temperature and high pressure using a diamond hydraulic press to complete the preparation of β-Si3N4 sintered body.

[0012] The beneficial effects of this invention are:

[0013] 1. This invention uses W and Co powder as binders and adds a small amount of graphite powder to form a WC-Co hard alloy phase, which enhances the toughness of the matrix. Co can "consume" excess C in the matrix, and C enters the Co lattice to form a Co-C solid solution alloy phase, which effectively avoids the remaining C from affecting the matrix performance and enhances the toughness of the matrix.

[0014] 2. This invention uses high-energy ball milling technology to crush and refine the raw material particles while fully mixing them. This can enhance the density, toughness and wear resistance of the matrix to a certain extent, while increasing the defect degree of the material particles and reducing the reaction activation energy.

[0015] 3. This invention uses a corundum tube as a container to perform vacuum high-temperature treatment on the Si3N4 billet. Under the capillary action between the Si3N4 and W particles, the molten Co and Ni fully infiltrate into the billet, which can effectively promote the uniformity of the matrix composition and reduce defects such as "agglomeration" and "bridging" introduced by the powder mixing process. The vacuum (negative pressure) environment can remove the air between the particles of each component, effectively prevent the material from oxidizing, and make it more conducive to the infiltration of molten metal into the surrounding area.

[0016] 4. This invention uses a pyrophyllite composite cavity as a high-pressure reaction vessel to prepare a high-toughness silicon nitride ceramic sintered body under high temperature and pressure. This method is highly operable and suitable for large-scale industrial production.

[0017] 5. The silicon nitride ceramic material prepared by this invention has a Vickers hardness of over 20 GPa, high toughness and high density, and a yield of over 95%. Attached Figure Description

[0018] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of the pyrophyllite composite block cavity assembly in the process of this invention.

[0020] Figure label:

[0021] 1. Carbon-containing raw material blank; 2. Small graphite sheet; 3. Plug; 4. Graphite tube; 5. Large graphite sheet; 6. Copper sheet; 7. Conductive steel cap; 8. Pyrophyllite composite block. Detailed Implementation

[0022] To address the problems in the background art, this invention presents a method for preparing ceramic blade material for tile cutters. This invention employs vacuum sintering technology, using a corundum tube as the reaction vessel. Molten metal is fully infiltrated into the green body under vacuum conditions. Then, high-temperature and high-pressure sintering technology is used to crystallize silicon nitride under high pressure, thereby preparing silicon nitride ceramic materials with high strength, toughness, and wear resistance. This method enables high-efficiency, mass production and industrial application.

[0023] The specific steps of the preparation method of this invention are as follows:

[0024] Using α-Si3N4 micro powder (99.9%, particle size in the nano- and micro-scales) as the hard phase matrix, ZrO2 (99.9%, particle size in the nano- and micro-scales) as the sintering aid, and W, Co, Cr, Ni, Ti, etc. (99.9%, particle size in the nano- and micro-scales) as binders, the binders are W and Co, and may also include Cr, Ni, or Ti. The mass ratio of α-Si3N4, sintering aid, and binder is 7:X:3-X (X = 0.05-0.5), the mass ratio of binder W to Co is 30:0.5-2, and the mass ratio of Co to other elements in the binder is 1:0-2. After being fully wet-mixed by vacuum high-energy ball milling for 1-10 hours, the mixture is dried in a vacuum drying oven to obtain a carbon-free mixed raw material. Carbon-free mixed raw materials are loaded into a mold and pre-pressed using a four-column press under a pressure of 5-20 MPa. The cylindrical carbon-free blank is then placed into a vacuum tube furnace cavity and subjected to high-temperature treatment (1500-1700℃) for 10-30 min in a vacuum environment. The high-temperature treated carbon-free blank is then crushed, a small amount of graphite powder is added, and the mixture is thoroughly mixed by vacuum low-speed ball milling for 1-5 h to obtain a carbon-containing mixed raw material. This material is then pre-pressed to obtain a carbon-containing blank. The carbon-containing blank is placed into a graphite heating cavity, and pyrophyllite composite blocks are assembled. The blank is then sintered using a diamond hydraulic press under high temperature and high pressure (4.0-5.5 GPa, 1250-1600℃) for 15 min-1 h to prepare a β-Si3N4 sintered body with high strength, good toughness, and wear resistance.

[0025] The method for preparing silicon nitride ceramics described in this invention employs high-energy ball milling technology, which refines particles while ensuring thorough mixing of raw materials, enhancing matrix density, increasing particle defect rate, and reducing reaction activation energy. Vacuum high-temperature heat treatment of the Si3N4 green body allows molten metal to fully infiltrate between green body particles, effectively promoting matrix composition homogeneity. The vacuum (negative pressure) environment removes air from between component particles, effectively preventing material oxidation. A silicon nitride ceramic sintered body is then prepared under high temperature and high pressure. This method is highly operable, produces silicon nitride with uniform texture, high strength, good toughness and wear resistance, and is suitable for large-scale industrial production.

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] As attached Figure 1As shown: 5g of α-Si3N4 with a particle size of 3-5μm, sintering aid ZrO2, and binders W and Co were selected as the initial raw materials (the mass ratio of α-Si3N4, sintering aid, and binder was 7:0.5:2.5 (W:Co = 30:1.5)). After thorough wet mixing via vacuum high-energy ball milling for 5 hours, the mixture was dried at 70℃ in a vacuum drying oven to obtain the mixed raw materials. The cylindrical blanks were pre-pressed using a four-column press at a pressure of 10MPa and then placed into a vacuum tube furnace cavity. The blanks were then subjected to high-temperature treatment at 1500℃ for 30 minutes under vacuum. The carbon-free preform after high-temperature treatment was crushed, and 0.07g of graphite powder was added. After thorough mixing by vacuum low-speed ball milling for 2 hours, it was pre-pressed at 10MPa. The carbon-containing raw material preform 1, small graphite sheets 2, and plugs 3 were loaded into a graphite tube 4. The three carbon-containing raw material preforms 1 and four small graphite sheets 2 were arranged alternately. The inner diameter of the graphite tube 4 was 17mm and the height was 16mm. Then, the graphite cavity and components 5-7 were placed into a pyrophyllite composite block 8. The dimensions of the pyrophyllite composite block 8 were 32.5mm×32.5mm×32.5mm, and the diameter of the composite cavity was 18mm. Silicon nitride was sintered at high temperature and high pressure on a diamond hydraulic press. The sintering conditions were 5.5GPa, 1550℃, and a holding time of 30min. After sintering, the temperature was slowly lowered to room temperature. After depressurization, three Φ14mm×2mm silicon nitride ceramic sheet sintered materials were obtained. The hardness of the sintered material was measured to be 23 GPa, and the fracture toughness was 13.5 MPa·m. 1 / 2 .

[0029] Example 2

[0030] As attached Figure 1As shown: 5g of α-Si3N4 with a particle size of 10-15μm, sintering aid ZrO2, and binders W and Co were selected as initial raw materials (the mass ratio of α-Si3N4, sintering aid, and binder was 7:0.3:2.7 (W:Co = 30:1)). After thorough wet mixing via vacuum high-energy ball milling for 2 hours, the mixture was dried at 70℃ in a vacuum drying oven to obtain the mixed raw materials. The cylindrical blanks were pre-pressed using a four-column press at a pressure of 5MPa and then placed into a vacuum tube furnace cavity. The blanks were then subjected to high-temperature treatment at 1600℃ for 30 minutes under vacuum. The carbon-free preform after high-temperature treatment was crushed, and 0.08g of graphite powder was added. After thorough mixing by vacuum low-speed ball milling for 2 hours, it was pre-pressed at 10MPa. The carbon-containing raw material preform 1, small graphite sheets 2, and plugs 3 were loaded into a graphite tube 4. The three carbon-containing raw material preforms 1 and four small graphite sheets 2 were arranged alternately. The inner diameter of the graphite tube 4 was 17mm and the height was 16mm. Then, the graphite cavity and components 5-7 were placed into a pyrophyllite composite block 8. The dimensions of the pyrophyllite composite block 8 were 32.5mm×32.5mm×32.5mm, and the diameter of the composite cavity was 18mm. Silicon nitride was sintered at high temperature and high pressure on a diamond hydraulic press. The sintering conditions were 5GPa, 1400℃, and a holding time of 50min. After sintering, the temperature was slowly lowered to room temperature. After depressurization, three Φ14mm×2mm silicon nitride ceramic sheet sintered materials were obtained. The hardness of the sintered material was measured to be 25 GPa, and the fracture toughness was 12.8 MPa·m. 1 / 2 .

[0031] Example 3

[0032] As attached Figure 1As shown: 5g of α-Si3N4 with a particle size of 0.5-1μm, sintering aid ZrO2, and binders W, Co, and Cr were selected as initial raw materials (the mass ratio of α-Si3N4, sintering aid, and binder was 7:0.5:2.5 (W:Co:Cr = 30:0.5:1)). After thorough wet mixing via vacuum high-energy ball milling for 5 hours, the mixture was dried at 70℃ in a vacuum drying oven to obtain the mixed raw materials. The cylindrical blanks were pre-pressed using a four-column press at a pressure of 15MPa and then placed into a vacuum tube furnace cavity. The blanks were then subjected to high-temperature treatment at 1550℃ for 30 minutes under vacuum. The carbon-free preform after high-temperature treatment was crushed, and 0.07g of graphite powder was added. After thorough mixing by vacuum low-speed ball milling for 3 hours, it was pre-pressed at 15MPa. The carbon-containing raw material preform 1, small graphite sheets 2, and plugs 3 were loaded into a graphite tube 4. The three carbon-containing raw material preforms 1 and four small graphite sheets 2 were arranged alternately. The inner diameter of the graphite tube 4 was 17mm and the height was 16mm. Then, the graphite cavity and components 5-7 were placed into a pyrophyllite composite block 8. The dimensions of the pyrophyllite composite block 8 were 32.5mm×32.5mm×32.5mm, and the diameter of the composite cavity was 18mm. Silicon nitride was sintered at high temperature and high pressure on a diamond hydraulic press. The sintering conditions were 4.5GPa, 1250℃, and a holding time of 30min. After sintering, the temperature was slowly lowered to room temperature. After depressurization, three Φ14mm×2mm silicon nitride ceramic sheet sintered materials were obtained. The hardness of the sintered material was measured to be 20 GPa, and the fracture toughness was 8.2 MPa·m. 1 / 2 .

[0033] This invention uses α-Si3N4 micro powder as the hard phase matrix and zirconium dioxide (ZrO2) as a sintering aid to promote the transformation of Si3N4 from the α phase to the β phase, increasing the matrix density. Tungsten (W), cobalt (Co), chromium (Cr), nickel (Ni), and titanium (Ti) are added as binder phases for toughening, and a small amount of graphite powder (C) is added. Using high-pressure sintering technology and a closed sintering chamber, a monolithic β-Si3N4 sheet sintered body is synthesized. This application refines the particles through high-energy ball milling, melts the metal infiltrating it into the billet under vacuum conditions, adds graphite powder, and mixes it through low-speed ball milling. Under high pressure, a β-Si3N4 sintered body with uniform texture, high strength, good toughness, and wear resistance is prepared. It is highly operable and suitable for large-scale industrial production.

[0034] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art, inspired by this description, design similar structures and implementations to the above embodiments without departing from the technical essence of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for preparing a ceramic blade material for a tile cutter, characterized in that: The method includes the following steps: ① Select α-Si3N4 powder, sintering aid powder, and binder powder as raw materials; ② The mixed powder raw materials selected in ① above are mixed in a certain proportion, vacuum high-energy ball milled for 1-10 hours to fully wet mix, and then dried in a vacuum drying oven to obtain carbon-free mixed raw materials; ③ The carbon-free mixed raw material obtained in ② is pre-pressed into a cylindrical blank and then placed into a vacuum tube furnace cavity. The blank is then subjected to high-temperature treatment in a vacuum environment using vacuum sintering technology. ④ The carbon-free green body obtained in ③ after high-temperature treatment is crushed, a small amount of graphite powder is added, and it is thoroughly mixed by vacuum low-speed ball milling to obtain carbon-containing mixed raw material. It is then pre-pressed to obtain a carbon-containing green body. ⑤ The carbon-containing preform from ④ is loaded into a graphite heating chamber, pyrophyllite composite blocks are assembled, and sintered under high temperature and high pressure using a diamond hydraulic press to complete the preparation of β-Si3N4 sintered body; In step ①, the raw materials are all nano- or micron-sized powder materials, with a single particle size or a mixture of multiple particle sizes. The sintering aid is ZrO2, and the binder is W, Co, α-Si3N4. The mass ratio of the sintering aid to the binder is 7:X:3-X, where X=0.05-0.

5. The mass ratio of binder W to Co is 30:0.5-2.

2. The method for preparing a ceramic blade material for a tile cutter according to claim 1, characterized in that: The binder also includes other elements such as Cr, Ni, or Ti, or mixtures thereof, and the mass ratio of Co to other elements in the binder is 1:0-2.

3. The method for preparing a ceramic blade material for a tile cutter according to claim 1, characterized in that: In step ②, the high-energy ball mill rotates at a speed of 500-800 rad / min, the ball milling time is 1-10 h, and the vacuum drying oven is dried at a temperature of 70℃.

4. The method for preparing a ceramic blade material for a tile cutter according to claim 1, characterized in that: In step ③, the powder forming pressure is 5-20 MPa, the high temperature treatment temperature is 1500-1700℃, and the treatment time is 10-30 min.

5. The method for preparing a ceramic blade material for a tile cutter according to claim 1, characterized in that: In step ④, the mass ratio of graphite powder to W powder is 1:16, the low-speed ball milling speed is 200-300 rad / min, the ball milling time is 1-5 h, and the powder forming pressure is 5-20 MPa.

6. The method for preparing a ceramic blade material for a tile cutter according to claim 1, characterized in that: In step ⑤, the carbon-containing blank is loaded into a graphite tube, which is then placed into the cavity of the pyrophyllite composite block. The blank is then subjected to high-temperature and high-pressure sintering on a diamond hydraulic press. The sintering conditions are 4.0-5.5 GPa, 1250-1600 ℃, and the sintering holding time is 15 min-1 h.

7. The silicon nitride ceramic prepared by any of the methods for preparing ceramic blade materials for tile cutters according to claims 1-6 is used to manufacture building cutter blades.

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