Diamond tool for imitating linen stone thick brick and preparation method thereof

Abstract

This invention discloses a diamond cutting tool for imitation granite thick bricks and its preparation method, including steps such as preparation of base powder, preparation of high-entropy alloy powder, preparation of grinding fabric, pre-pressing, tunnel furnace sintering, and tunnel furnace sintering. This invention improves the preparation process of the diamond cutting tool for imitation granite thick bricks by introducing high-entropy alloy powder combined with iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder during the preparation of the grinding fabric. The high-entropy alloy powder and iron-copper-phosphorus alloy powder form a reinforcing phase in the fabric, thereby improving the overall structural strength of the diamond cutting tool and making it more impact-resistant and wear-resistant. The preparation method is more suitable for diamond cutting tools with high-entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder as the main skeleton structure, improving the hardness, wear resistance, and density of the prepared diamond cutting tool, making it more suitable for grinding imitation granite thick bricks with a thickness of up to 2 cm.

Description

Technical Field

[0001] This invention relates to the field of ceramic tile processing technology, and in particular to a diamond tool for imitation granite thick bricks and its preparation method. Background Technology

[0002] Marble is a type of granite with a speckled surface, mostly black and white or red and black spots. It is one of the densest and hardest types of granite. Natural marble is highly decorative, offering a rustic and natural aesthetic. Its textured patterns are highly sought after by consumers, aligning well with the growing consumer trend towards healthy, environmentally friendly, and natural aesthetics in architectural decoration. Therefore, it is frequently used in the building decoration industry and is increasingly favored. However, as a natural material, natural marble has a long formation cycle, resulting in high costs during processing and shaping. Grinding and carving are time-consuming and inefficient. Furthermore, it is easily broken and crumbled upon impact, rendering it unusable. Long-term mining of marble represents a significant waste of natural resources.

[0003] Therefore, to meet market demand and enrich the production and decorative techniques of architectural ceramics, it is necessary to research existing architectural ceramic production processes and develop ceramic tiles that mimic natural granite. These tiles should truly achieve a natural, seamless effect comparable to natural stone, solving the problems of limited processing and wear that hinder the creation of aesthetically pleasing stone-like tiles. Because of their high similarity to natural stone, their application scenarios and methods are basically the same, primarily for curtain wall cladding and outdoor paving.

[0004] However, imitation granite tiles are generally quite thick, reaching up to 2cm in thickness, more than twice the thickness of ordinary ceramic tiles; their strength is 3-5 times that of ordinary stone; and their water absorption rate is low, less than 0.05%, making them prone to chipping during processing. This poses a significant challenge for abrasive manufacturers, as it's difficult to balance the lifespan and sharpness of the grinding wheels, resulting in a generally shorter lifespan—only 1 / 3 to 1 / 2 the lifespan of grinding ordinary ceramic tiles. Furthermore, traditional abrasive manufacturers use graphite molds to produce diamond tools through hot pressing, which is easily affected by the oxidation level and thermal conductivity of graphite. In addition, the significant temperature difference between the center and edges of the mold leads to variations in the height loss during sintering even within the same mold, resulting in inconsistent quality.

[0005] Therefore, it is necessary to further optimize the preparation method of diamond tools for imitation granite bricks, and to prepare high-performance tools for imitation granite bricks with high hardness, strong wear resistance, and a good balance of sharpness and lifespan, so as to solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing diamond tools for imitation granite thick bricks. The preparation method of this invention is more suitable for the preparation of diamond tools with high entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder as the main skeleton structure, so as to improve the hardness, wear resistance, density and other properties of the prepared diamond tools, making them more suitable for grinding imitation granite thick bricks with a thickness of up to 2cm.

[0007] The objective of this invention is achieved through the following solution:

[0008] A method for preparing a diamond tool for imitating thick granite bricks includes the following steps:

[0009] Step 1: Preparation of base powder

[0010] Weigh out the copper powder, iron powder and tin powder according to the formula and place them in a three-dimensional mixer. Set the speed to 350 rpm and the mixing time to 2 hours. Mix thoroughly and evenly to obtain the base powder.

[0011] Step 2: Preparation of high-entropy alloy powder

[0012] Weigh out the required amounts of cobalt powder, chromium powder, nickel powder, copper powder, iron powder, and aluminum powder respectively. Place the weighed raw materials into a planetary ball mill. Set the ball mill speed to 340-360 rpm. After mixing for 2 hours, ball mill for 6-6.5 hours for secondary mechanical alloying to obtain high-entropy alloy powder.

[0013] Step 3: Preparation of grinding fabric

[0014] Weigh out the required amounts of diamond powder, copper powder, tin powder, high-entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder respectively, place them in a three-dimensional mixer, set the speed to 500 rpm, and the mixing time to 1.5 h, and mix evenly to obtain the grinding material.

[0015] Step 4: Pre-compression molding

[0016] Pour the base powder weighed according to the formula into the mold, smooth it out, then pour in the fabric and press it with a tooling. Remove the tooling and smooth it out again. Next, place the pressure ring on the smoothed fabric and put the entire mold into the press. Set the pressure to 12-15 MPa for cold pre-pressing.

[0017] Step 5: Sintering in a tunnel furnace

[0018] The pre-pressed mold is pushed into a tunnel furnace for sintering. After being taken out of the furnace, it is cooled, demolded, and then machined, sharpened, and drilled to produce diamond tools for imitation granite thick bricks.

[0019] Preferably, in step 3, the diamond powder is first cleaned, half of the amount of chromium powder in the high-entropy alloy powder raw material is weighed and added together with the diamond into a three-dimensional mixer and mixed evenly. After cold pressing, sintering and pulverizing, chromium-coated diamond powder is obtained.

[0020] As a further explanation of the above scheme, in step 5, the sintering temperature zones of the tunnel furnace are set as follows: heating zone 1, heating zone 2, heating zone 3, heating zone 4, heating zone 5, heating zone 6, heating zone 7, heating zone 8, and heating zone 9; the sintering temperatures from heating zone 1 to heating zone 9 are respectively: 550℃, 650℃, 700℃, 750℃, 800℃, 825℃, 825℃, 825℃, and 825℃; the boat pushing frequency is 15 min / time.

[0021] As a further explanation of the above scheme, in step 5, the pressure and holding time of heating zones one through five are as follows: the pressure of heating zone one is 5.5 MPa, and the holding time is 4.5 min; the pressure of heating zones two through four is 5.6 MPa, and the holding time is 5 min; the pressure of heating zone five is 5.8 MPa, and the holding time is 5.5 min; the pressure of heating zones six through nine is 6 MPa, and the holding time is 6 min.

[0022] As a further explanation of the above scheme, the grinding material in step 3 is prepared from the following components by mass: 3-4% diamond powder, 12-15% copper powder, 1-5% tin powder, 35-40% high entropy alloy powder, 3-6% phosphorus-iron alloy powder, and 30-35% iron-copper-phosphorus alloy powder; the sum of the mass percentages of the above components is 100%.

[0023] The mass ratio of the high-entropy alloy powder to the phosphorus-iron alloy powder and the iron-copper-phosphorus alloy powder is (8-10):

[0024] (1-2): (5-7).

[0025] As a further explanation of the above scheme, in step 2, the high-entropy alloy powder is prepared from the following raw materials in parts by mass: 15-20% cobalt powder, 18-22% chromium powder, 10-20% nickel powder, 10-20% copper powder, 10-15% iron powder, and 4-6% aluminum powder; the sum of the mass percentages of the above components is 100%.

[0026] As a further explanation of the above scheme, the ball-to-material ratio of the planetary ball mill in step 2 is 10:1, and the transmission ratio of revolution to rotation is 1:2; the particle size of the high-entropy alloy powder is 12-14nm.

[0027] As a further explanation of the above scheme, the grinding material in step 3 is prepared from the following components by weight: 3.5% diamond powder, 15% copper powder, 4% tin powder, 40% high entropy alloy powder, 5% phosphorus-iron alloy powder, and 32.5% iron-copper-phosphorus alloy powder.

[0028] As a further explanation of the above scheme, in the raw materials of the grinding fabric in step 3, the diamond powder has a particle size of 5-15μm and a diamond purity of 99.8%; the copper powder and tin powder have a mesh size of 300-400 mesh; the phosphorus-iron alloy powder has a particle size of 2-15μm; and the iron-copper-phosphorus alloy powder has a particle size of 3-8μm.

[0029] As a further explanation of the above scheme, in step 1, the base material is prepared from the following components by mass: 50-60% copper powder, 25-30% iron powder, and 15-20% tin powder; the sum of the mass percentages of the above components is 100%.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. This invention improves the manufacturing process of diamond tools for imitation granite thick bricks. During the preparation of the grinding surface, high-entropy alloy powder is introduced in combination with iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder. These high-entropy alloy powders and iron-copper-phosphorus alloy powders form a reinforcing phase in the surface, thereby improving the overall structural strength of the diamond tool and enhancing its impact resistance and wear resistance. Furthermore, the synergistic effect of the iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder further enhances the diffusion effect, severe lattice distortion effect, and grain suppression effect of the high-entropy alloy powder, resulting in a finer and more uniform grain structure during diamond tool manufacturing, which helps improve the tool's hardness and wear resistance. On the other hand, this invention employs a tunnel furnace sintering method and sets multiple heating zones at different temperatures, optimizing the heating rate, sintering pressure, and holding time. Under controlled temperature zones, a crystal structure that is more conducive to improving the performance of the diamond tool is further formed, while simultaneously promoting the bonding between diamond and alloy powder. During the gradual heating process, porosity and defects on the surface of the diamond tool product can be reduced or eliminated, improving the surface quality of the tool.

[0032] In other words, the tunnel furnace sintering of the present invention is more suitable for the preparation of diamond tools with high entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder as the main skeleton structure, so as to improve the hardness, wear resistance, density and other properties of the prepared diamond tools, making them more suitable for grinding applications of imitation granite thick bricks with a thickness of up to 2cm.

[0033] 2. In the manufacturing process of the diamond tool for imitation granite thick bricks of the present invention, the base material and the grinding surface are prepared separately. The base material is set to fix it to the diamond tool base. The base material is mainly composed of copper powder, which improves the overall support strength and helps to form a bottom support structure in the diamond tool. This layered structure can improve the overall strength and stability of the tool; it allows the tool to better adhere to the base and prevents tooth breakage during grinding; at the same time, it can avoid the problem of tile chipping caused by the tool grinding the base during grinding. Furthermore, the separate preparation of the base material and the surface material allows for more flexible selection of components and proportions during the manufacturing process. The use of precious metals is eliminated in the preparation of the base material, which helps to reduce the production cost of the tool.

[0034] 3. To improve the bonding between diamond powder and high-entropy alloy powder, during the preparation of the grinding material, diamond and a portion of chromium powder are pretreated to form a coated metal-diamond interface on the diamond surface. This helps reduce oxidation of the diamond surface, maintain the characteristics of the diamond particles, and improves the adhesion and bonding strength between the diamond and the high-entropy alloy. This allows the diamond particles to be better embedded in the framework structure mainly composed of high-entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder. This helps prevent the diamond particles from falling off during use and further extends the life of the diamond tool. Detailed Implementation

[0035] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0036] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0037] This invention provides a method for preparing a diamond tool for imitating thick granite bricks, comprising the following steps:

[0038] Step 1: Preparation of base powder

[0039] Weigh out the copper powder, iron powder and tin powder according to the formula and place them in a three-dimensional mixer. Set the speed to 350 rpm and the mixing time to 2 hours. Mix thoroughly and evenly to obtain the base powder.

[0040] Step 2: Preparation of high-entropy alloy powder

[0041] Weigh out the required amounts of cobalt powder, chromium powder, nickel powder, copper powder, iron powder, and aluminum powder respectively. Place the weighed raw materials into a planetary ball mill. Set the ball mill speed to 340-360 rpm. After mixing for 2 hours, ball mill for 6-6.5 hours for secondary mechanical alloying to obtain high-entropy alloy powder.

[0042] Step 3: Preparation of grinding fabric

[0043] Weigh out the required amounts of diamond powder, copper powder, tin powder, high-entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder respectively, place them in a three-dimensional mixer, set the speed to 500 rpm, and the mixing time to 1.5 h, and mix evenly to obtain the grinding material.

[0044] Step 4: Pre-compression molding

[0045] Pour the base powder weighed according to the formula into the mold, smooth it out, then pour in the fabric and press it with a tooling. Remove the tooling and smooth it out again. Next, place the pressure ring on the smoothed fabric and put the entire mold into the press. Set the pressure to 12-15 MPa for cold pre-pressing.

[0046] Step 5: Sintering in a tunnel furnace

[0047] The pre-pressed mold is pushed into a tunnel furnace for sintering. After being taken out of the furnace, it is cooled, demolded, and then machined, sharpened, and drilled to produce diamond tools for imitation granite thick bricks.

[0048] As a further preferred embodiment, in step 3, the diamond powder is first cleaned, half of the amount of chromium powder in the high-entropy alloy powder raw material is weighed and added together with the diamond into a three-dimensional mixer to be mixed evenly, and then cold-pressed green blanks are prepared, sintered, and pulverized to obtain chromium-coated diamond powder.

[0049] As a further preferred embodiment, in step 5, the sintering temperature zones of the tunnel furnace are set as follows: heating zone 1, heating zone 2, heating zone 3, heating zone 4, heating zone 5, heating zone 6, heating zone 7, heating zone 8, and heating zone 9; the sintering temperatures from heating zone 1 to heating zone 9 are respectively: 550℃, 650℃, 700℃, 750℃, 800℃, 825℃, 825℃, 825℃, and 825℃; the boat pushing frequency is 15 min / time.

[0050] As a further preferred embodiment, in step 5, the pressure and holding time of heating zones one through five are as follows: heating zone one pressure is 5.5 MPa, holding time is 4.5 min; heating zones two through four pressure are all 5.6 MPa, holding time is 5 min; heating zone five pressure is 5.8 MPa, holding time is 5.5 min; heating zones six through nine pressure are all 6 MPa, holding time is 6 min.

[0051] As a further preferred embodiment, the grinding fabric in step 3 is prepared from the following components by mass: 3-4% diamond powder, 12-15% copper powder, 1-5% tin powder, 35-40% high-entropy alloy powder, 3-6% phosphorus-iron alloy powder, and 30-35% iron-copper-phosphorus alloy powder; the sum of the mass percentages of the above components is 100%.

[0052] The mass ratio of the high-entropy alloy powder to the phosphorus-iron alloy powder and the iron-copper-phosphorus alloy powder is (8-10):(1-2):(5-7).

[0053] As a further preferred embodiment, in step 2, the high-entropy alloy powder is prepared from the following raw materials in parts by mass: 15-20% cobalt powder, 18-22% chromium powder, 10-20% nickel powder, 10-20% copper powder, 10-15% iron powder, and 4-6% aluminum powder; the sum of the mass percentages of the above components is 100%.

[0054] As a further preferred embodiment, the ball-to-material ratio of the planetary ball mill in step 2 is 10:1, and the transmission ratio of revolution to rotation is 1:2; the particle size of the high-entropy alloy powder is 12-14 nm.

[0055] As a further preferred option, in step 2, the required raw materials and WC balls are weighed at a ball-to-material ratio of 10:1, placed together in a vacuum glove box into a WC container and sealed to maintain an argon atmosphere in the container, and then placed on a planetary ball mill for ball milling.

[0056] As a further preferred embodiment, in step 2, the high-entropy alloy powder after ball milling is impregnated with alcohol under inert gas protection, then removed and dried. This forms a protective film on the surface of the high-entropy alloy powder, preventing the oxides on its surface from rapidly oxidizing and bonding with diamond, thus affecting surface hardness.

[0057] As a further preferred embodiment, the grinding material in step 3 is prepared from the following components in parts by weight: 3.5% diamond powder, 15% copper powder, 4% tin powder, 40% high entropy alloy powder, 5% phosphorus-iron alloy powder, and 32.5% iron-copper-phosphorus alloy powder.

[0058] As a further preferred embodiment, in the raw materials of the grinding fabric in step 3, the diamond powder has a particle size of 5-15μm and a diamond purity of 99.8%; the copper powder and tin powder have a mesh size of 300-400 mesh; the phosphorus-iron alloy powder has a particle size of 2-15μm; and the iron-copper-phosphorus alloy powder has a particle size of 3-8μm.

[0059] As a further preferred embodiment, the ferrophosphorus alloy powder is selected from Taihe Huijin Company and is of the FeP grade. 24The iron-copper-phosphorus alloy powder is selected from Taihe Huijin Company and is designated as grade X3-321.

[0060] As a further preferred embodiment, in step 1, the base material is prepared from the following components by mass: 50-60% copper powder, 25-30% iron powder, and 15-20% tin powder; the sum of the mass percentages of the above components is 100%.

[0061] Preparation method and component ratio analysis:

[0062] Specifically, in the diamond tool manufacturing process of the present invention, the base material and the grinding surface are prepared separately. The base material is used to fix the diamond tool base. The base material is mainly composed of copper powder, which improves the overall support strength and helps to form a bottom support structure in the diamond tool. This layered structure can improve the overall strength and stability of the tool; it allows the tool to better adhere to the base and prevents tooth breakage during grinding; at the same time, it can avoid the problem of the tool grinding the base and causing tile-like chipping during grinding. Furthermore, the separate preparation of the base material and the surface material allows for more flexible selection of components and proportions during the preparation process. The use of precious metals is eliminated in the preparation of the base material, which helps to reduce the production cost of the tool.

[0063] In the preparation of grinding fabric, high-entropy alloy powder is introduced in combination with iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder. These high-entropy alloy powders and iron-copper-phosphorus alloy powders form a reinforcing phase in the fabric, thereby improving the overall structural strength of the diamond tool and enhancing its impact resistance and wear resistance. Furthermore, the synergistic effect of the iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder further enhances the diffusion effect, severe lattice distortion effect, and grain suppression effect of the high-entropy alloy powder, resulting in a finer and more uniform grain structure during diamond tool preparation, which helps improve the tool's hardness and wear resistance. On the other hand, this invention employs a tunnel furnace sintering method and sets multiple heating zones at different temperatures, optimizing the heating rate, sintering pressure, and holding time. This controlled temperature range is beneficial for improving the crystal structure of the diamond tool and promoting the bonding between diamond and alloy powder. During the gradual heating process, porosity and defects on the surface of the diamond tool product can be reduced or eliminated, improving the surface quality of the tool.

[0064] In other words, the tunnel furnace sintering of the present invention is more suitable for the preparation of diamond tools with high entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder as the main skeleton structure, so as to improve the hardness, wear resistance, density and other properties of the prepared diamond tools, making them more suitable for grinding applications of imitation granite thick bricks with a thickness of up to 2cm.

[0065] This invention utilizes the superior properties of high-entropy alloys to lower the sintering temperature, inhibit ceramic grain growth, and exhibit excellent wettability to ceramics. Through experimentation, the applicant discovered that introducing phosphorus-iron alloy powder and iron-copper-phosphorus alloy powder into the high-entropy alloy-based skeleton structure design can further suppress grain growth, forming a fine and uniform grain structure. This helps improve the hardness and wear resistance of the cutting tool. Furthermore, it improves the tool's thermal stability, enabling it to maintain excellent grinding performance even under high-temperature conditions. The phosphorus and iron components in the phosphorus-iron alloy may enhance the overall corrosion resistance of the cutting tool, making it more durable in humid or corrosive environments.

[0066] The high-entropy alloy powder of this invention is a nano-scale high-entropy alloy powder, which helps to increase the surface area, better coat diamond, and provide more bonding sites for diamond bonding, thereby improving the mechanical bonding strength with diamond. Elements such as Cr and Ni in the high-entropy alloy powder, especially Ni, play a catalytic role in the nucleation and growth process of diamond, which helps diamond particles form a more uniform and firm bond on the metal matrix. In addition, Ni has good adhesion, which helps to form a stronger bond between diamond particles and the alloy matrix.

[0067] Through extensive testing, the applicant discovered that the optimal skeletal structure and the highest diamond mechanical bonding strength are achieved when the mass ratio of high-entropy alloy powder to phosphorus-iron alloy powder and iron-copper-phosphorus alloy powder is 8:1:6.5.

[0068] The following are specific embodiments of the present invention. Unless otherwise specified, the raw materials, equipment and other materials used in the following embodiments can be obtained by purchasing.

[0069] Examples 1-3 and Comparative Examples 1-6

[0070] Weigh the grinding fabric raw materials according to the proportions in Table 1, and prepare diamond tools according to the steps in Examples 1-3. See Table 1 for details:

[0071] Table 1. Grinding fabric ratios for Examples 1-3 and Comparative Examples 1-3

[0072]

[0073]

[0074] In the diamond cutting tools prepared by this invention, the volume ratio of the base material to the face material is 1:1; Table 2 below shows the proportions of the base material powder in Examples 1-3 of this invention:

[0075] Table 2. Powder Proportioning Table for Examples 1-3 and Comparative Examples 1-3

[0076]

[0077] Table 3 below shows the high-entropy alloy powder formulations for Examples 1-3 and Comparative Examples 1-3:

[0078] Table 3. High-entropy alloy powder proportioning table for Examples 1-3

[0079]

[0080] Unless otherwise specified, the raw materials used in the above embodiments and comparative examples are the same to ensure the comparability of the test results.

[0081] Preparation method

[0082] The preparation of the diamond tools for imitation granite thick bricks in Examples 1-3 and Comparative Examples 1-3 includes the following steps:

[0083] Step 1: Preparation of base powder

[0084] Weigh out the copper powder, iron powder and tin powder according to the formula and place them in a three-dimensional mixer. Set the speed to 350 rpm and the mixing time to 2 hours. Mix thoroughly and evenly to obtain the base powder.

[0085] Step 2: Preparation of high-entropy alloy powder

[0086] Weigh out the cobalt powder, chromium powder, nickel powder, copper powder, iron powder, and aluminum powder according to the formula. Put the weighed raw materials into a planetary ball mill. Set the speed of the ball mill to 340 rpm. After mixing for 2 hours, ball mill for 6 hours for secondary mechanical alloying to obtain high entropy alloy powder.

[0087] Step 3: Preparation of grinding fabric

[0088] First, the diamond powder is cleaned on the surface. Half of the amount of chromium powder in the high-entropy alloy powder raw material is weighed and added to the three-dimensional mixer along with the diamond powder. The mixture is then mixed evenly and cold-pressed green blanks are prepared, sintered, and pulverized to obtain chromium-coated diamond powder.

[0089] Then, weigh out the pretreated diamond powder and copper powder, tin powder, high-entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder according to the formula, respectively, and place them in a three-dimensional mixer. Set the speed to 500 rpm and the mixing time to 1.5 h. Mix evenly to obtain the grinding material.

[0090] Step 4: Pre-compression molding

[0091] Pour the base powder weighed according to the formula into the mold, smooth it out, then pour in the fabric, press it with a tooling, remove the tooling and smooth it out again; then place the pressure ring on the smoothed fabric, and put the whole mold into the press, set the pressure to 15Mpa for cold pre-pressing.

[0092] Step 5: Sintering in a tunnel furnace

[0093] The pre-pressed mold is pushed into the tunnel furnace. The sintering temperature zones of the tunnel furnace are set as heating zone 1, heating zone 2, heating zone 3, heating zone 4, heating zone 5, heating zone 6, heating zone 7, heating zone 8, and heating zone 9. The sintering temperatures of heating zones 1 to 9 are 550℃, 650℃, 700℃, 750℃, 800℃, 825℃, 825℃, and 825℃, respectively. The pressure and holding time of heating zones 1 to 5 are as follows: The pressure of heating zone 1 is... The pressure was 5.5 MPa for 4.5 min; the pressure in heating zones 2-4 was 5.6 MPa for 5 min; the pressure in heating zone 5 was 5.8 MPa for 5.5 min; the pressure in heating zones 6-9 was 6 MPa for 6 min; the boat was pushed at a frequency of 15 min / time for sintering; after cooling, demolding, and lathe, sharpening, and drilling were performed to obtain diamond tools for imitation granite thick bricks.

[0094] Comparative Example 4

[0095] Referring to Example 1, the difference in Comparative Example 4 is that hot pressing sintering process is used in step 5, while the rest of the formula composition, dosage and preparation process are the same as in Example 1.

[0096] The hot pressing and sintering process is as follows:

[0097] The mold that has been pre-pressed in step 4 is placed in a hot pressing sintering furnace for sintering. The initial temperature is 450℃, and the heating rate is set to 90℃ / min. When the temperature reaches 720℃, the heating is stopped, and the mold is held for 5 minutes before being removed, demolded, and allowed to cool naturally to obtain the final product.

[0098] Comparative Example 5

[0099] Referring to Example 1, the difference in Comparative Example 5 is that the pretreatment step of diamond and chromium powder is omitted in step 3, while the rest of the formulation, dosage, and preparation process are the same as in Example 1.

[0100] Comparative Example 6

[0101] Referring to Example 1, the difference in Comparative Example 6 is that in step 5, the temperature of heating zones one through nine is 825°C, while the rest of the formulation, dosage, and preparation process are the same as in Example 1.

[0102] Comparative Example 7

[0103] Referring to Example 1, the difference in Comparative Example 7 is that the preparation step of the base material is omitted, and the components of the abrasive fabric are used.

[0104] Effect evaluation and performance testing

[0105] The performance of the low-cost waterproof ceramic tile stain-resistant agents of Examples 1-3 and Comparative Examples 1-6 was tested. The test items and results are shown in Table 2.

[0106] The diamond grinding wheel formulations of Examples 1-3 and Comparative Examples 1-7 were molded into test blades with dimensions of 50×20×10mm. Their density, bending strength, hardness, and cutting performance were tested using the following methods:

[0107] (1) Density testing method

[0108] Density was determined according to GB / T 3850-2015, and the results were recorded as a percentage (%).

[0109] (2) Bending strength test method

[0110] The bending strength was tested according to GB / T 232-2010 using a universal electronic testing machine (STM Corporation), and the results were recorded in N.

[0111] (3) Hardness testing method

[0112] Hardness was tested according to the specific provisions of the national standard GB / T 230.1-2018, and bending strength was tested using a universal electronic testing machine (STM Corporation). The results were recorded in HRB.

[0113] The test items and results are shown in Table 4 below.

[0114] Table 4: Summary of performance test results of diamond tools used in imitation granite thick bricks

[0115]

[0116]

[0117] As can be seen from the data in Table 4 above, the density of the diamond tools prepared in Examples 1-3 of this invention exceeds 97%, the bending strength can reach more than 1760N, and the hardness reaches 115HRB. This indicates that after the formulation and process improvement, the hardness, wear resistance, density and other properties of the diamond tools prepared by this invention are improved, making them more suitable for grinding diamond-like thick bricks with a thickness of up to 2cm.

[0118] Referring to Example 1, Example 2 reduced the amount of high-entropy alloy powder and increased the amount of iron-copper-phosphorus alloy powder. The reduction of high-entropy alloy powder affected the coating effect of diamond, which in turn affected the bonding strength of diamond and the stability of the skeleton structure, thus affecting the overall performance of diamond tools.

[0119] In Example 3, the amount of high-entropy alloy powder was kept constant, the amount of phosphorus-iron alloy powder was reduced, and the amount of iron-copper-phosphorus alloy powder was increased. The density and hardness were slightly lower than those in Example 1.

[0120] In Comparative Example 1, significantly reducing the amount of high-entropy alloy powder resulted in a substantial decrease in the bending strength of the diamond tool. This was because the significant reduction in high-entropy alloy powder significantly affected the stability of the skeleton structure, leading to a decrease in the mechanical bonding strength of the diamond, as well as a reduction in density and hardness, thus affecting the overall performance of the tool.

[0121] In Comparative Example 2, without the addition of high-entropy alloy powder, it is difficult to form a stable skeletal structure, and the density, bending strength, hardness, and other properties of the diamond tool prepared therefrom are significantly worse.

[0122] In Comparative Example 3, due to the addition of excessive copper and tin powder, the use of iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder was eliminated. Tin powder has a very low melting point and is severely lost during sintering, which is not conducive to sintering. At the same time, the lack of iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder also affected the grain structure to some extent, which also affected the hardness and bending strength of the diamond tool.

[0123] Comparative Example 4 uses hot pressing sintering to prepare diamond tools. Since high-entropy alloys are prone to oxidation after mechanical alloying, they are easily oxidized when exposed to air and hot pressing sintering is carried out. The oxides on the surface lead to bonding with diamond, affecting the surface hardness. The density, bending strength, hardness and other properties of the prepared diamond tools are also significantly deteriorated.

[0124] The diamond in Comparative Example 5 was not pretreated with chromium powder, which affected the adhesion and bonding strength between the diamond and the high-entropy alloy during the preparation process, affecting the overall stability of the framework structure, resulting in a decrease in the mechanical bonding strength of the diamond, as well as a decrease in density and hardness.

[0125] In Comparative Example 6, the lack of multiple heating zones at different temperatures resulted in significant loss of powders with melting points below 825°C, such as tin powder. Furthermore, the use of a uniform sintering method without controlling and adjusting parameters such as heating rate and sintering pressure hindered the formation of crystal structures that enhance the performance of diamond tools. It may also cause defects such as surface porosity, significantly degrading the density, bending strength, and hardness of the prepared diamond tools.

[0126] The diamond tool prepared in Comparative Example 7 did not use a copper powder-based base layer. Compared to a matrix base layer preparation, the diamond tool lacked a more stable bottom support, and its hardness was slightly reduced. More importantly, the overall preparation cost increased by more than 1.5 times, which is not conducive to optimizing the economics of tool preparation.

[0127] In summary, in the diamond tool manufacturing process of the present invention, the base material and the grinding surface are prepared separately. The base material is set to fix it to the diamond tool base. The base material is mainly copper powder, which improves the overall support strength and helps to form a bottom support structure in the diamond tool. Such a layered structure can improve the overall strength and stability of the tool.

[0128] Furthermore, during the preparation of the grinding fabric, high-entropy alloy powder is introduced in combination with iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder. These high-entropy alloy powders and iron-copper-phosphorus alloy powders form a reinforcing phase in the fabric, thereby improving the overall structural strength of the diamond tool and enhancing its impact resistance and wear resistance. In addition, the synergistic effect of iron-copper-phosphorus alloy powder and phosphorus-iron alloy powder further enhances the diffusion effect, severe lattice distortion effect, and grain suppression effect of the high-entropy alloy powder, resulting in a finer and more uniform grain structure during diamond tool preparation, which helps improve the tool's hardness and wear resistance. On the other hand, this invention employs a tunnel furnace sintering method and sets multiple heating zones at different temperatures, optimizing the heating rate, sintering pressure, and holding time. This controlled temperature range is beneficial for improving the crystal structure of the diamond tool and promoting the bonding between diamond and alloy powder. During the gradual heating process, porosity and defects on the surface of the diamond tool product can be reduced or eliminated, improving the surface quality of the tool.

[0129] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a diamond tool for imitating thick granite bricks, characterized in that, Includes the following steps: Step 1: Preparation of base powder Weigh out the copper powder, iron powder and tin powder according to the formula and place them in a three-dimensional mixer. Set the speed to 350 rpm and the mixing time to 2 hours. Mix thoroughly and evenly to obtain the base powder. Step 2: Preparation of high-entropy alloy powder Weigh out the required amounts of cobalt powder, chromium powder, nickel powder, copper powder, iron powder, and aluminum powder respectively. Place the weighed raw materials into a planetary ball mill. Set the ball mill speed to 340-360 rpm. After mixing for 2 hours, ball mill for 6-6.5 hours for secondary mechanical alloying to obtain high-entropy alloy powder. Step 3: Preparation of grinding fabric Weigh out the required amounts of diamond powder, copper powder, tin powder, high-entropy alloy powder, phosphorus-iron alloy powder, and iron-copper-phosphorus alloy powder respectively, place them in a three-dimensional mixer, set the speed to 500 rpm, and the mixing time to 1.5 h, and mix evenly to obtain the grinding material. Step 4: Pre-compression molding Pour the base powder weighed according to the formula into the mold, smooth it out, then pour in the fabric and press it with a tooling. Remove the tooling and smooth it out again. Next, place the pressure ring on the smoothed fabric and put the entire mold into the press. Set the pressure to 12-15 MPa for cold pre-pressing. Step 5: Sintering in a tunnel furnace The pre-pressed mold is pushed into a tunnel furnace for sintering. After being taken out of the furnace, it is cooled, demolded, and then machined, sharpened, and drilled to produce diamond tools for imitation granite thick bricks. The grinding material in step 3 is prepared from the following components by mass percentage: 3-4% diamond powder, 12-15% copper powder, 1-5% tin powder, 35-40% high-entropy alloy powder, 3-6% phosphorus-iron alloy powder, and 30-35% iron-copper-phosphorus alloy powder; the sum of the mass percentages of the above components is 100%. The mass ratio of the high-entropy alloy powder to the phosphorus-iron alloy powder and the iron-copper-phosphorus alloy powder is (8-10):(1-2):(5-7).

2. The method for preparing diamond tools for imitation granite thick bricks as described in claim 1, characterized in that, In step 3, the diamond powder is first cleaned, half of the amount of chromium powder in the high-entropy alloy powder raw material is weighed and added to the three-dimensional mixer along with the diamond powder to mix evenly, and then cold-pressed green blanks are prepared, sintered, and pulverized to obtain chromium-coated diamond powder.

3. The method for preparing diamond tools for imitation granite thick bricks as described in claim 1, characterized in that, In step 5, the sintering temperature zones of the tunnel furnace are set as follows: heating zone 1, heating zone 2, heating zone 3, heating zone 4, heating zone 5, heating zone 6, heating zone 7, heating zone 8, and heating zone 9; the sintering temperatures from heating zone 1 to heating zone 9 are 550℃, 650℃, 700℃, 750℃, 800℃, 825℃, 825℃, and 825℃ respectively; the boat pushing frequency is 15 min / time.

4. The method for preparing diamond tools for imitation granite thick bricks as described in claim 3, characterized in that, In step 5, the pressure and holding time of heating zones 1 to 5 are as follows: heating zone 1 pressure is 5.5 MPa, holding time is 4.5 min; heating zones 2 to 4 pressure are all 5.6 MPa, holding time is 5 min; heating zone 5 pressure is 5.8 MPa, holding time is 5.5 min; heating zones 6 to 9 pressure are all 6 MPa, holding time is 6 min.

5. The method for preparing diamond tools for imitation granite thick bricks as described in claim 1, characterized in that, The ball-to-material ratio of the planetary ball mill in step 2 is 10:1, and the transmission ratio of revolution to rotation is 1:2; the particle size of the high-entropy alloy powder is 12-14 nm.

6. The method for preparing diamond cutting tools for imitation granite thick bricks as described in claim 1, characterized in that, The grinding material in step 3 is prepared from the following components by weight: 3.5% diamond powder, 15% copper powder, 4% tin powder, 40% high entropy alloy powder, 5% phosphorus-iron alloy powder, and 32.5% iron-copper-phosphorus alloy powder.

7. The method for preparing diamond cutting tools for imitation granite thick bricks as described in claim 1, characterized in that, In the raw materials for the grinding fabric in step 3, the diamond powder has a particle size of 5-15μm and a diamond purity of 99.8%; the copper powder and tin powder have a mesh size of 300-400 mesh; the phosphorus-iron alloy powder has a particle size of 2-15μm; and the iron-copper-phosphorus alloy powder has a particle size of 3-8μm.

8. The method for preparing diamond cutting tools for imitation granite thick bricks as described in claim 1, characterized in that, In step 1, the base material is prepared from the following components by mass: 50-60% copper powder, 25-30% iron powder, and 15-20% tin powder; the sum of the mass percentages of the above components is 100%.

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