Grinding wheel applied to low water absorption ceramic middle plate and preparation method thereof

Abstract

This invention discloses a grinding wheel for use in ceramic plates with low water absorption and its preparation method. The grinding wheel comprises 3-5% diamond powder, 10-15% copper powder, 3-5% tin powder, and 65-85% skeleton material powder. The mass ratio of diamond powder to skeleton material powder is 1:(15-22). The skeleton material powder includes high-entropy alloy powder, electrolytic FeCuNiSn alloy powder, and CuSn alloy powder. The preparation method includes the preparation of high-entropy alloy powder, the preparation of skeleton material powder, the preparation of mixed powders, pre-pressing, and plasma sintering. This invention optimizes the component ratio of the diamond grinding wheel, introduces high-entropy alloy powder as the main skeleton material, and combines this with optimized preparation process. The resulting diamond grinding wheel exhibits superior performance in terms of hardness, bending strength, and density. The hardness can reach 120 HRB, the bending strength can reach up to 1800 MPa, and the density can reach 98.5 g / ml, significantly exceeding the performance of diamond grinding wheels prepared from ordinary iron-based pre-alloyed powders.

Description

Technical Field

[0001] This invention relates to the field of ceramic tile processing technology, and in particular to a grinding wheel for use in ceramic slabs with low water absorption and its preparation method. Background Technology

[0002] Medium-thickness ceramic slabs typically refer to ceramic slabs with a thickness of 7.3mm-8mm, falling between thin slabs and standard products, and with dimensions of 300×600mm or 400×800mm. Their water absorption rate is between low-absorption polished tiles and high-absorption ceramic tiles. The biggest advantage of medium-thickness ceramic slabs is their versatility for both wall and floor installation, enhancing the overall spatial effect. Wall installation is a significant advantage. In terms of decoration, the moderate thickness of medium-thickness ceramic slabs not only provides a seamless decorative effect but also allows for wall and floor installation, greatly enhancing the overall spatial effect and making it easier to showcase brand personality. Compared to thin ceramic slabs, medium-thickness ceramic slabs are harder, making them suitable for traditional cement mortar installation. This avoids the drawbacks of thinner slabs requiring tile adhesive during installation, and they also perform well in resisting wear, scratches, and pressure.

[0003] Existing ceramic medium plates present the following processing challenges: due to their high hardness, brittleness, thinness, and high linear speed, especially some low water absorption ceramic medium plates, they are prone to chipping, cracking, and edge damage during processing. Moreover, they require high sharpness and generally have a short lifespan. In addition, the industry's unit price is generally low, which has always been a problem for mold manufacturers.

[0004] Therefore, it is necessary to further develop a high-performance ceramic grinding wheel with high hardness, strong wear resistance, and a good balance of sharpness and lifespan to solve the problems existing in the above-mentioned technologies. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a grinding wheel for use in ceramic plates with low water absorption. The diamond grinding wheel product prepared by this invention has the following performance characteristics: hardness can reach 120HRB; bending strength can reach up to 1800MPa; and density can reach 98.5g / ml. Its performance far exceeds that of diamond grinding wheels prepared from ordinary iron-based pre-alloyed powder.

[0006] A second objective of this invention is to provide a method for preparing a grinding wheel for use in ceramic plates with low water absorption.

[0007] One of the objectives of this invention is achieved through the following solution:

[0008] A grinding wheel for use in ceramic plates with low water absorption is prepared from the following components by mass: 3-5% diamond powder, 10-15% copper powder, 3-5% tin powder, and 65-85% skeleton material powder; the sum of the mass percentages of the above components is 100%.

[0009] The mass ratio of diamond powder to matrix material powder is 1:(15-22);

[0010] The skeleton material powder is prepared from high-entropy alloy powder, electrolytic FeCuNiSn alloy powder, and CuSn alloy powder prepared by electric explosion method in a mass ratio of (8-10):(3-6):(2-3).

[0011] Furthermore, the high-entropy alloy powder is prepared from the following raw materials in parts by mass: 10-20% Co powder, 15-20% Cr powder, 10-20% Ni powder, 10-20% Cu powder, 15-25% Fe powder, and 8-10% Al powder; the sum of the mass percentages of the above components is 100%.

[0012] Furthermore, in the high-entropy alloy raw material, the mass ratio of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder is (4-6):(5-7):(5-7):(4-6):(5-7):(2-3).

[0013] Furthermore, the mass ratio of the diamond powder to the high-entropy alloy powder is (1.6-2):(24-25).

[0014] Furthermore, the particle size of the electrolytic FeCuNiSn alloy powder is 6-12 μm, and the median particle size of the CuSn alloy powder is 50-80 nm.

[0015] Furthermore, the electrolytic FeCuNiSn alloy powder is selected from Taihe Huijin Company and is designated as grade X6-621 electrolytic FeCuNiSn alloy powder.

[0016] Furthermore, the CuSn powder is CuSn10 alloy powder prepared by Ningbo Luofei nano-electro-explosion method.

[0017] Furthermore, the diamond powder has a particle size of 200-355μm and a diamond purity of 99.5%; the copper powder and tin powder have mesh sizes of 300-400 mesh, respectively.

[0018] The second objective of this invention is achieved by the following technical solution:

[0019] A method for preparing a grinding wheel for use in ceramic plates with low water absorption, as described above, includes the following steps:

[0020] Step 1: Preparation of high-entropy alloy powder

[0021] Weigh out the required amounts of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder respectively. Place the weighed raw materials and WC balls into a WC container, then fill it with argon gas, seal the container, and then place it into a planetary ball mill. Set the ball mill speed to 300 rpm and ball mill for 8-10 hours to mechanically alloy and obtain high-entropy alloy powder.

[0022] Step 2: Preparation of framework material powder

[0023] The high-entropy alloy powder obtained in step 1, along with electrolytic FeCuNiSn alloy powder and CuSn alloy powder, are placed in a planetary ball mill. WC balls are used, and the ball-to-material ratio is set to 10:1. The mixture is milled for 2-3 hours to obtain the skeleton material powder.

[0024] Step 3: Preparation of mixed powder

[0025] The skeleton material powder obtained in step 2 is mixed evenly with diamond powder, copper powder and tin powder using a three-dimensional mixer to obtain a mixed powder.

[0026] Step 4: Pre-compression molding

[0027] The mixed powder obtained in step 3 is placed into the prepared graphite mold and pre-pressed using a hydraulic press. The pressure of the hydraulic press is 10 MPa and the pressing time is 5 min.

[0028] Step 5: Plasma sintering

[0029] After the pre-pressing process in step 4 is completed, the pressed product is placed in a spark plasma sintering equipment. After vacuuming, inert gas is introduced, and vacuum sintering is carried out at a temperature of 820-860℃ and a pressure of 30-40MPa. The temperature is held for 4-5 minutes, then removed, cooled, and polished to obtain the grinding wheel used in ceramic medium plates with low water absorption.

[0030] Furthermore, in step 1, the ball-to-material ratio of the planetary ball mill is set to 15:1, and the particle size of the prepared high-entropy alloy powder is 12-16 nm.

[0031] Furthermore, in step 3, the rotation speed of the three-dimensional mixer is set to 400 rpm and the mixing time is set to 3 hours.

[0032] Furthermore, in step 5, the vacuum degree of the plasma sintering equipment is 3.3*10-2; the heating rate is 20-25℃ / min; the pressure is 40MPa; and the holding time is 4min.

[0033] Compared with the prior art, the beneficial effects of the present invention are at least in the following aspects:

[0034] 1. This invention uses nano-level high-entropy alloy powder and ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a specific ratio to prepare the framework material, replacing the traditional Fe-based pre-alloyed powder. This reduces the problems of traditional iron-based alloy powder being difficult to cold-press and affecting the overall performance of the prepared diamond grinding wheel. In the process of preparing the framework material by mechanical alloying with nano-level high-entropy alloy powder and ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a specific ratio, some atoms such as copper and tin in the ultrafine powder can diffuse into the high-entropy alloy powder during ball milling and sintering. The diffusion process results in better lattice distortion, which can lead to changes in the crystal structure of the alloy. Better lattice distortion and metal diffusion can give the alloy a better balance of softness and hardness, providing more bonding sites for diamond bonding, thereby improving the mechanical bonding strength with diamond.

[0035] In addition, in the selection of high-entropy alloy powder raw materials, this invention introduces elements such as Cr and Ni that have an affinity for diamond, and rationally designs their ratio, particle size and distribution uniformity to further optimize the microstructure of the alloy powder, so as to form an interface phase that is more suitable for bonding with diamond, thereby further improving the bonding performance with diamond.

[0036] On the other hand, by optimizing the formulation of high-entropy alloy powder and optimizing the ratio with ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder, the prepared skeleton material powder is easier to form, and the nanocrystalline phase and amorphous phase can play a solid solution strengthening role, ensuring the overall performance of the sintered product.

[0037] 2. This invention optimizes the diamond particle size and the ratio of the diamond to the skeleton material prepared by mechanical alloying with nano-sized high-entropy alloy powder and ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a specific proportion. This ensures that the diamond is uniformly distributed in the skeleton material powder, achieving a more uniform particle distribution, increasing the hardness and wear resistance of the grinding wheel, making it more suitable for high-strength processes such as grinding and cutting. Through a suitable mechanical alloying process, a stronger interfacial bond is formed between the diamond and the high-entropy alloy powder and electrolytic alloy powder, improving the cutting performance of the grinding wheel and facilitating more efficient cutting and grinding operations, thus increasing processing efficiency. By comprehensively considering the diamond particle size and the mechanical alloying ratio of the high-entropy alloy and electrolytic alloy, the overall performance of the grinding wheel can be optimized, including comprehensive improvements in hardness, wear resistance, strength, and heat resistance. This overcomes bottlenecks and yields a diamond grinding wheel with excellent properties such as high-temperature hardness, high wear resistance, high cutting speed and precision, and high toughness.

[0038] 3. The optimized formulation and preparation method of the diamond grinding wheel of the present invention complement each other. The mixed powder is placed into a prepared graphite mold, pre-pressed by a hydraulic press, and then placed in the instrument cavity of the discharge plasma for vacuum sintering. The pre-pressing can make the high-entropy alloy powder, FeCuNiSn alloy powder, and CuSn alloy powder form a uniform skeleton structure. This skeleton structure provides a stable support base in the subsequent plasma sintering, which helps to form a uniform diamond distribution.

[0039] Furthermore, this treatment can increase the density of the powder and reduce the porosity, thereby increasing the overall density of the grinding wheel; providing a more stable material basis for subsequent plasma sintering; and spark plasma sintering can cause ions to diffuse at high speed, so in the plasma sintering process, the formation of a more stable skeleton structure after diffusion helps to form a more uniform and dense grinding wheel structure.

[0040] On the other hand, it also helps to reduce grain growth and prevent excessively large grains, thereby maintaining the size of diamond particles and improving the hardness, grinding performance, strength, toughness, and wear resistance of diamond.

[0041] The diamond grinding wheel product prepared by this invention has excellent performance in terms of hardness, bending strength, and density. Its hardness can reach 120 HRB, its bending strength can reach up to 1800 MPa, and its density can reach 98.5 g / ml. Its performance far exceeds that of diamond grinding wheels prepared from ordinary iron-based pre-alloyed powder. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] This invention provides a grinding wheel for use in ceramic plates with low water absorption, which is prepared from the following components in parts by weight: 3-5% diamond powder, 10-15% copper powder, 3-5% tin powder, and 65-85% skeleton material powder; the sum of the above components by weight percentage is 100%.

[0045] The mass ratio of diamond powder to matrix material powder is 1:(15-22);

[0046] The skeleton material powder is prepared from high-entropy alloy powder, electrolytic FeCuNiSn alloy powder, and CuSn alloy powder in a mass ratio of (8-10):(3-6):(2-3).

[0047] Preferably, the high-entropy alloy powder is prepared from the following raw materials in parts by mass: 10-20% Co powder, 15-20% Cr powder, 10-20% Ni powder, 10-20% Cu powder, 15-25% Fe powder, and 8-10% Al powder; the sum of the mass percentages of the above components is 100%.

[0048] Preferably, in the high-entropy alloy raw material, the mass ratio of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder is (4-6):(5-7):(5-7):(4-6):(5-7):(2-3).

[0049] Preferably, the mass ratio of diamond powder to high-entropy alloy powder is (1.6-2):(24-25).

[0050] Preferably, the particle size of the electrolytic FeCuNiSn alloy powder is 6-12 μm, and the particle size of the CuSn alloy powder is 50-80 nm.

[0051] Preferably, the electrolytic FeCuNiSn alloy powder is an electrolytic FeCuNiSn alloy powder of grade X6-621 purchased from Taihe Huijin Company.

[0052] Preferably, the CuSn powder is CuSn10 alloy powder prepared by Ningbo Luofei nano-electro-explosion method.

[0053] Preferably, the diamond powder has a particle size of 200-355 μm and a diamond purity of 99.5%; the copper powder and tin powder have mesh sizes of 300-400 mesh, respectively.

[0054] Preparation method and component ratio analysis:

[0055] In the above-mentioned component formulation of this invention, the high-entropy alloy component possesses four core effects: the high-entropy alloy effect, the slow co-diffusion effect, the severe lattice distortion effect, and the cocktail effect. These effects enable the high-entropy alloy to achieve a simple solid solution structure and are conducive to the formation of nanophases or amorphous phases. Through appropriate alloy formulation design, superior properties different from traditional alloys can be obtained. These include good high-temperature hardness, good wear resistance, excellent corrosion resistance, and high resistivity. This invention utilizes the superior properties of high-entropy alloys to lower the sintering temperature, inhibit ceramic grain growth, and exhibit excellent wettability in ceramics.

[0056] High-entropy alloys containing some main elements such as Cu, Ti, Cr, and Co generally have good corrosion resistance. Furthermore, the unique simple structure and low free enthalpy of high-entropy alloys further enhance their corrosion resistance, thus exhibiting extremely strong corrosion resistance.

[0057] Electrolytic FeCuNiSn alloy powder is used in the preparation of diamond grinding wheels to replace part of the tin powder, reducing production costs, effectively reducing the outflow of elemental tin, increasing the sintering temperature of the matrix, and improving product formability. CuSn alloy powder with high mechanical strength and hardness, good casting and processing performance, corrosion resistance, and excellent load-bearing capacity is selected, and the addition of a copper-tin intermediate alloy improves the performance of the matrix alloy and the stability of the sintering process. This invention uses nano-level high-entropy alloy powder and ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a specific ratio to prepare a skeleton material with high-entropy alloy powder as the main component, replacing the traditional Fe-based pre-alloy powder and reducing the need for traditional iron-based alloys. The powder is difficult to cold press and mold, which affects the overall performance of the prepared diamond grinding wheel. In the process of preparing the skeleton material by mechanical alloying with nano-sized high-entropy alloy powder and ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a specific ratio, some atoms such as copper and tin in the ultrafine electrolytic powder can diffuse into the high-entropy alloy powder. The nano-sized high-entropy alloy powder helps to increase the surface area and promote the diffusion reaction. During its diffusion process, better lattice distortion is obtained, which can lead to changes in the crystal structure of the alloy. Better lattice distortion and metal diffusion can make the alloy have a better balance of softness and hardness, providing more bonding sites for diamond bonding, thereby improving the mechanical bonding strength with diamond.

[0058] Through experiments, the applicant discovered that by introducing elements with an affinity for diamond, such as Cr and Ni, into the high-entropy alloy powder raw material selection, and by increasing their mass ratio, optimizing particle size and distribution uniformity, the microstructure of the alloy powder is further optimized, forming an interface phase more suitable for bonding with diamond, which can further improve the bonding performance with diamond. Elements such as Cr and Ni, 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.

[0059] On the other hand, by optimizing the formulation of high-entropy alloy powder and the ratio with ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder, the prepared skeleton material powder is easier to form, and the nanocrystalline and amorphous phases can play a solid solution strengthening role, ensuring the overall performance of the sintered product.

[0060] Through extensive testing, the applicant discovered that when the ratio of diamond to matrix material powder is 1:20, and the ratio of high-entropy alloy powder to electrolytic FeCuNiSn alloy powder and CuSn alloy powder in the matrix material powder is 5:2:1, the mechanical bonding strength between diamond and matrix material is the highest, resulting in a more uniform particle distribution and a stronger interfacial bond with the matrix material powder. This improves the hardness and wear resistance of the grinding wheel, making it more suitable for high-intensity processes such as grinding and cutting.

[0061] This invention also provides a method for preparing a grinding wheel for use in ceramic plates with low water absorption, comprising the following steps:

[0062] Step 1: Preparation of high-entropy alloy powder

[0063] Weigh out the required amounts of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder respectively. Place the weighed raw materials and WC balls into a WC container, then fill it with argon gas, seal the container, and then place it into a planetary ball mill. Set the ball mill speed to 300 rpm and ball mill for 8-10 hours to mechanically alloy and obtain high-entropy alloy powder.

[0064] Step 2: Preparation of framework material powder

[0065] The high-entropy alloy powder obtained in step 1, along with electrolytic FeCuNiSn alloy powder and CuSn alloy powder, are placed in a planetary ball mill. WC balls are used, and the ball-to-material ratio is set to 10:1. The mixture is milled for 2-3 hours to obtain the skeleton material powder.

[0066] Step 3: Preparation of mixed powder

[0067] The skeleton material powder obtained in step 2 is mixed evenly with diamond powder, copper powder and tin powder using a three-dimensional mixer to obtain a mixed powder.

[0068] Step 4: Pre-compression molding

[0069] The mixed powder obtained in step 3 is placed into the prepared graphite mold and pre-pressed using a hydraulic press. The pressure of the hydraulic press is 10 MPa and the pressing time is 5 min.

[0070] Step 5: Plasma sintering

[0071] After the pre-pressing process in step 4 is completed, the pressed product is placed in a spark plasma sintering equipment. After vacuuming, inert gas is introduced, and vacuum sintering is carried out at a temperature of 820-860℃ and a pressure of 30-40MPa. The temperature is held for 4-5 minutes, then removed, cooled, and polished to obtain the grinding wheel used in ceramic medium plates with low water absorption.

[0072] The completed grinding wheel is welded onto the iron substrate, then undergoes precision machining, blade sharpening, sandblasting, drilling, and dynamic balancing before being packaged and stored.

[0073] More preferably, in step 2, the high-entropy alloy powder is mixed with electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a mass ratio of 5:2:1. In this invention, selecting this ratio of high-entropy alloy powder to electrolytic FeCuNiSn alloy powder and CuSn alloy powder to prepare the framework material powder allows some atoms, such as copper and tin, in the ultrafine electrolytic powder to diffuse into the high-entropy alloy powder during ball milling and sintering. This diffusion process results in better lattice distortion, which can lead to changes in the crystal structure of the alloy. Better lattice distortion and metal diffusion can give the alloy a better balance of hardness and softness, providing more bonding sites for diamond bonding, thereby improving the mechanical bonding strength with diamond.

[0074] Preferably, in step 1, the ball-to-material ratio of the planetary ball mill is set to 15:1, and the particle size of the prepared high-entropy alloy powder is 12-16 nm. In this invention, nanoscale high-entropy alloys are used to replace the industry's traditional iron-based pre-alloyed powders, breaking through the bottlenecks of traditional alloys and obtaining a new type of alloy with excellent properties such as high-temperature hardness, high wear resistance, high cutting speed and precision, and high toughness. Furthermore, by adding different elements, high-entropy alloys with unique properties can be obtained, thereby allowing for the control of alloy performance. Moreover, the sintering temperature can be reduced, inhibiting ceramic grain growth while improving diamond holding power.

[0075] Preferably, in step 3, the rotation speed of the three-dimensional mixer is set to 400 rpm, and the mixing time is 3 hours. The combined use of a ball mill and a three-dimensional mixer effectively improves the mixing effect, ensures uniform distribution of various powder particles, makes it easier for the skeleton material to coat the surface of the diamond particles, enhances the diamond holding effect, and improves the overall performance of the grinding wheel.

[0076] Preferably, in step 5, the vacuum degree of the plasma sintering equipment is 3.3*10-2; the heating rate is 20-25℃ / min; the pressure is 40MPa; and the holding time is 4min.

[0077] The optimized formulation and preparation method of the diamond grinding wheel of the present invention complement each other. The mixed powder is placed into a prepared graphite mold, pre-pressed by a hydraulic press, and then placed in the instrument cavity of the spark plasma for vacuum sintering. The pre-pressing can make the high-entropy alloy powder, FeCuNiSn alloy powder, and CuSn alloy powder form a uniform skeleton structure. This skeleton structure provides a stable support base in the subsequent plasma sintering, which helps to form a uniform diamond distribution.

[0078] Furthermore, this treatment can increase the density of the powder and reduce porosity, thereby increasing the overall density of the grinding wheel; it provides a more stable material basis for subsequent plasma sintering. During the plasma sintering process, a stable skeleton structure helps to form a more uniform and dense grinding wheel structure.

[0079] On the other hand, it also helps to reduce grain growth and prevent excessively large grains, thereby maintaining the size of diamond particles and improving the hardness, grinding performance, strength, toughness, and wear resistance of diamond.

[0080] The diamond grinding wheel product prepared by this invention has the following performance characteristics: hardness can reach 120HRB; bending strength can reach up to 1800MPa; and density can reach 98.5g / ml. Its performance far exceeds that of ordinary iron-based pre-alloyed powder.

[0081] Compared to diamond cutting tips with metal binders prepared by traditional hot pressing and sintering, the grains are less likely to grow, the diamond is better held, the sintering temperature field is more uniform, and the temperature deviation is smaller. This is more conducive to obtaining products that balance sharpness and lifespan, and the energy consumption is lower, which meets the requirements of energy conservation and emission reduction.

[0082] 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.

[0083] Examples 1-3 and Comparative Examples 1-7

[0084] Weigh the raw materials according to the proportions in Table 1, and prepare the products according to the steps in Examples 1-3. See Table 1 for details:

[0085] Table 1. Raw material ratios for Examples 1-3 and Comparative Examples 1-3

[0086]

[0087]

[0088] Explanation of component dosages in Examples 1-3 and Comparative Examples 1-5 above:

[0089] The skeleton material in Example 1 was prepared by high-entropy alloy powder, electrolytic FeCuNiSn alloy powder, and CuSn alloy powder in a mass ratio of 5:2:1, and the ratio of diamond powder to skeleton material powder was 1:20.

[0090] Referring to Example 1, Example 2 reduced the amount of high-entropy alloy powder and increased the amount of electrolytic FeCuNiSn alloy powder, while keeping the amounts of other components unchanged.

[0091] Referring to Example 1, Example 3 reduced the amount of electrolytic FeCuNiSn alloy powder and increased the amount of CuSn alloy powder, while keeping the amounts of other components unchanged.

[0092] Referring to Example 1, Comparative Example 1 omitted the electrolytic FeCuNiSn alloy powder and increased the amount of CuSn alloy powder, while keeping the amounts of other components unchanged.

[0093] Referring to Example 1, in Comparative Example 2, the ratio of high-entropy alloy powder to electrolytic FeCuNiSn alloy powder was interchanged, that is, the amount of high-entropy alloy powder was greatly reduced and the amount of electrolytic FeCuNiSn alloy powder was greatly increased, while the amounts of other components remained unchanged.

[0094] Referring to Example 1, in Comparative Example 3, the amount of high-entropy alloy powder was significantly reduced and replaced with an equal amount of iron powder.

[0095] In Examples 1-3 and Comparative Examples 1-3, the raw materials of the high-entropy alloy powder contain the following proportions: Co powder 16%; Cr powder 21%; Ni powder 21%; Cu powder 16%; Fe powder 18%; and Al powder 8%.

[0096] Comparative Example 4

[0097] Based on Example 1, in the high-entropy alloy powder raw material of Comparative Example 4, the amount of Cr powder was reduced and the amount of Al was increased, while the amounts of other components remained unchanged.

[0098] Comparative Example 5

[0099] Based on Example 1, in the high-entropy alloy powder raw material of Comparative Example 4, the amount of Ni powder was reduced and the amount of Al was increased, while the amounts of other components remained unchanged.

[0100] 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.

[0101] Preparation method

[0102] The preparation of grinding wheels for use in ceramic medium plates with low water absorption in Examples 1-3 and Comparative Examples 1-5 includes the following steps:

[0103] Step 1: Preparation of high-entropy alloy powder

[0104] Weigh out the required amounts of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder respectively. Place the weighed raw materials and WC balls into a WC container, then fill it with argon gas, seal the container, and then place it into a planetary ball mill. Set the ball mill speed to 300 rpm and the ball-to-material ratio to 15:1. Perform ball milling for 8-10 hours to mechanically alloy and obtain high-entropy alloy powder.

[0105] Step 2: Preparation of framework material powder

[0106] The high-entropy alloy powder obtained in step 1, along with electrolytic FeCuNiSn alloy powder and CuSn alloy powder, are placed in a planetary ball mill. WC balls are used, and the ball-to-material ratio is set to 10:1. The mixture is milled for 2-3 hours to obtain the skeleton material powder.

[0107] Step 3: Preparation of mixed powder

[0108] The skeleton material powder obtained in step 2 was mixed with diamond powder, copper powder and tin powder using a three-dimensional mixer. The speed of the three-dimensional mixer was set to 400 rpm and the mixing time was 3 hours. The mixture was mixed evenly to obtain a mixed powder.

[0109] Step 4: Pre-compression molding

[0110] The mixed powder obtained in step 3 is placed into the prepared graphite mold and pre-pressed using a hydraulic press. The pressure of the hydraulic press is 10 MPa and the pressing time is 5 min.

[0111] Step 5: Plasma sintering

[0112] After the pre-pressing process in step 4 is completed, the pressed product is placed in a spark plasma sintering equipment. After evacuation, inert gas is introduced to maintain a vacuum of 3.3*10-2. Vacuum sintering is carried out at a temperature of 820-860℃ and a pressure of 40MPa. The product is held at this temperature for 4 minutes, then removed, cooled, and polished to obtain the grinding wheel used in ceramic medium plates with low water absorption.

[0113] Comparative Example 6

[0114] Referring to Example 1, the difference in Comparative Example 6 is that step 2, namely the preparation step of the skeleton material powder, is omitted. Instead, the high-entropy alloy powder prepared in step 1 is directly mixed with other components according to the formula amount using a three-dimensional mixer. The remaining steps and parameters are the same as in Example 1.

[0115] Comparative Example 7

[0116] Referring to Example 2, the difference in Comparative Example 7 is that the pre-pressing step in step 4 is omitted, and the mixed powder in step 3 is placed into a spark plasma sintering apparatus for the sintering operation in step 5.

[0117] Effect evaluation and performance testing

[0118] 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:

[0119] (1) Density testing method

[0120] Density was determined according to GB / T 3850-2015, and the results were recorded as a percentage (%).

[0121] (2) Bending strength test method

[0122] 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.

[0123] (3) Hardness testing method

[0124] 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.

[0125] The test items and results are shown in Table 2 below:

[0126] Table 2: Summary of Grinding Wheel Performance Test Results Applied to Low Water Absorption Ceramic Plates

[0127]

[0128] According to Table 2 above, Example 1 is the optimal embodiment of the present invention. The skeleton material in Example 1 is prepared by high entropy alloy powder, electrolytic FeCuNiSn alloy powder, and CuSn alloy powder in a mass ratio of 5:2:1. The ratio of diamond powder to skeleton material powder is 1:20. In terms of hardness, bending strength, and density, the hardness can reach 120 HRB; the bending strength can reach up to 1800 MPa; and the density can reach 98.5 g / ml.

[0129] Referring to Example 1, Example 2 reduced the amount of high-entropy alloy powder and increased the amount of electrolytic FeCuNiSn alloy powder, reducing the amount of high-entropy alloy powder to 80% of the amount used in Example 1. The structure of the skeleton material was affected, and the bonding performance with diamond was significantly affected. With the increase in the amount of electrolytic FeCuNiSn alloy powder, the sintering performance of the alloy matrix was improved to a certain extent, but the overall performance of the diamond grinding wheel was reduced.

[0130] Referring to Example 1, Example 3 reduced the amount of electrolytic FeCuNiSn alloy powder and increased the amount of CuSn alloy powder. Although the addition of CuSn alloy powder as a copper-tin intermediate alloy can improve the performance of the matrix alloy and the stability of the sintering process, the lack of electrolytic FeCuNiSn alloy powder will still affect the diffusion reaction of elements and the mechanical bonding strength with diamond, thus affecting the overall performance of the diamond grinding wheel.

[0131] Referring to Example 1, Comparative Example 1 eliminated the electrolytic FeCuNiSn alloy powder and increased the amount of CuSn alloy powder. This had a greater impact on the diffusion reaction of elements, the stable structure formation of the prepared framework material, and the mechanical bonding strength of diamond. Therefore, it had a more significant impact on the density and other properties of the prepared diamond grinding wheel.

[0132] Referring to Example 1, in Comparative Example 2, the ratio of high-entropy alloy powder to electrolytic FeCuNiSn alloy powder was interchanged, that is, the amount of high-entropy alloy powder was greatly reduced and the amount of electrolytic FeCuNiSn alloy powder was greatly increased. With less high-entropy alloy powder, it is difficult to form a stable skeleton structure, which affects the diffusion effect of metal elements from ultrafine electrolytic alloy powder to high-entropy alloy powder, reduces the mechanical bonding strength between the skeleton material powder and diamond, and has a significant impact on the overall performance of the prepared diamond grinding wheel.

[0133] Referring to Example 1, in Comparative Example 3, the amount of high-entropy alloy powder was significantly reduced and replaced with an equal amount of iron powder. It was difficult to form a stable skeleton structure. Even with iron powder as a substitute, it was difficult to ensure the cold pressing effect of the powder, which also reduced the mechanical bonding strength between the skeleton material powder and diamond.

[0134] In Examples 1-3 and Comparative Examples 1-3, the raw materials of the high-entropy alloy powder contain the following proportions: Co powder 16%; Cr powder 21%; Ni powder 21%; Cu powder 16%; Fe powder 18%; and Al powder 8%.

[0135] Based on Example 1, in the high-entropy alloy powder raw material of Comparative Example 4, the amount of Cr powder was reduced and the amount of Al was increased. In the high-entropy alloy powder raw material of Comparative Example 5, the amount of Ni powder was reduced and the amount of Al was increased. Since Ni plays a catalytic role in the nucleation and growth of diamond in high-entropy alloy powder, it helps diamond particles to form a more uniform and firm bond on the metal matrix. Reducing the amount of Ni weakens this catalytic effect. Cr can also play a catalytic role to a certain extent, but relatively speaking, Ni has a greater effect. Therefore, reducing the amount of Ni has a more significant impact on the performance of the prepared diamond grinding wheel.

[0136] Referring to Example 1, the difference in Comparative Example 6 is that step 2, namely the preparation step of the framework material powder, is omitted. The high-entropy alloy powder prepared in step 1 is directly mixed with other components according to the formula amount using a three-dimensional mixer. The step of preparing the framework material with high-entropy alloy powder and ultrafine electrolytic FeCuNiSn alloy powder and CuSn alloy powder in a specific ratio is omitted. This will affect the lattice distortion and metal diffusion effect of the high-entropy alloy powder, and have a significant impact on the diamond bonding strength.

[0137] The difference in Comparative Example 7 is that step 4, the pre-pressing step, is omitted. Instead, the mixed powder from step 3 is placed in a spark plasma sintering device for the sintering operation in step 5. Therefore, the pre-pressing process that allows the high-entropy alloy powder, FeCuNiSn alloy powder, and CuSn alloy powder to form a uniform skeleton structure and provide a supporting foundation is lacking, which affects the bonding and distribution of diamond.

[0138] (4) Cutting performance test method

[0139] The grinding wheel prepared in the optimal embodiment 1 was used to cut a low water absorption medium plate with a specification of 400*800mm and a thickness of 8mm from Dongpeng Ceramics Company. The cutting performance was tested at a linear speed of 66 pieces / min.

[0140] The test results are recorded in Table 3 below:

[0141] Table 3. Test data on the cutting performance of diamond grinding wheels

[0142]

[0143]

[0144] Compared with the average service life of grinding wheels produced by traditional grinding wheel manufacturers, the service life of the grinding wheels prepared in Examples 1-3 of this invention is increased by more than 50-100%, which greatly improves the cutting performance and service life of the grinding wheels, and does not produce chipping, edge damage or bottom damage.

[0145] 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 grinding wheel for use in low water absorption ceramic slabs, characterized by the fact that, It is prepared from the following components in parts by weight: 3-5% diamond powder, 10-15% copper powder, 3-5% tin powder, and 80% matrix material powder; the sum of the above components by weight is 100%. The mass ratio of diamond powder to matrix material powder is 1:(15-22); The skeleton material powder is prepared from high-entropy alloy powder, electrolytic FeCuNiSn alloy powder, and CuSn alloy powder prepared by electric explosion method in a mass ratio of (8-10):(3-6):(2-3).

2. The abrasive wheel for use in a low water absorption ceramic slab as claimed in claim 1, wherein The high-entropy alloy powder is prepared from the following raw materials in parts by mass: 10-20% Co powder, 15-20% Cr powder, 10-20% Ni powder, 10-20% Cu powder, 15-25% Fe powder, and 8-10% Al powder; the sum of the mass percentages of the above components is 100%.

3. The grinding wheel for use in ceramic medium plates with low water absorption as described in claim 2, characterized in that, In the high-entropy alloy raw material, the mass ratio of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder is (4-6):(5-7):(5-7):(4-6):(5-7):(2-3).

4. The grinding wheel for use in ceramic medium plates with low water absorption as described in claim 1, characterized in that, The mass ratio of diamond powder to high-entropy alloy powder is (1.6-2):(24-25).

5. The grinding wheel for use in ceramic medium plates with low water absorption as described in claim 1, characterized in that, The electrolytic FeCuNiSn alloy powder has a particle size of 6-12 μm, and the CuSn alloy powder has a particle size of 50-80 nm.

6. The grinding wheel for use in ceramic medium plates with low water absorption as described in claim 1, characterized in that, The diamond powder has a particle size of 200-355μm and a diamond purity of 99.5%; the copper powder has a mesh size of 300-400 mesh; and the tin powder has a mesh size of 300-400 mesh.

7. A method for preparing a grinding wheel for use in ceramic medium plates with low water absorption, as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Preparation of high-entropy alloy powder Weigh out the required amounts of Co powder, Cr powder, Ni powder, Cu powder, Fe powder, and Al powder respectively. Place the weighed raw materials and WC balls into a WC container, then fill it with argon gas, seal the container, and then place it into a planetary ball mill. Set the ball mill speed to 300 rpm and ball mill for 8-10 hours to mechanically alloy and obtain high-entropy alloy powder. Step 2: Preparation of framework material powder The high-entropy alloy powder obtained in step 1, along with electrolytic FeCuNiSn alloy powder and CuSn alloy powder, are placed in a planetary ball mill. WC balls are used, and the ball-to-material ratio is set to 10:

1. The mixture is milled for 2-3 hours to obtain the skeleton material powder. Step 3: Preparation of mixed powder The skeleton material powder obtained in step 2 is mixed evenly with diamond powder, copper powder and tin powder using a three-dimensional mixer to obtain a mixed powder. Step 4: Pre-compression molding The mixed powder obtained in step 3 is placed into the prepared graphite mold and pre-pressed using a hydraulic press. The pressure of the hydraulic press is 10 MPa and the pressing time is 5 min. Step 5: Plasma sintering After the pre-pressing process in step 4 is completed, the pressed product is placed in a spark plasma sintering equipment. After vacuuming, inert gas is introduced, and vacuum sintering is carried out at a temperature of 820-860℃ and a pressure of 30-40MPa. The temperature is held for 4-5 minutes, then removed, cooled, and polished to obtain the grinding wheel used in ceramic medium plates with low water absorption.

8. The method for preparing a grinding wheel for use in ceramic medium plates with low water absorption as described in claim 7, characterized in that, In step 1, the ball-to-material ratio of the planetary ball mill is set to 15:1, and the particle size of the high-entropy alloy powder prepared is 12-16 nm.

9. The method for preparing a grinding wheel for use in ceramic medium plates with low water absorption as described in claim 7, characterized in that, In step 3, the rotation speed of the three-dimensional mixer is set to 400 rpm and the mixing time is set to 3 hours.

10. The method for preparing a grinding wheel for use in ceramic medium plates with low water absorption as described in claim 7, characterized in that, In step 5, the vacuum level of the plasma sintering equipment is 3.

3. 10-2; heating rate is 20-25℃ / min, pressure is 40MPa, and holding time is 4min.

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