A group of diamond micro-powder applied to a fine grinding wheel

Abstract

The application relates to the technical field of materials, in particular to a group diamond micro-powder applied to a fine grinding wheel. The group diamond micro-powder applied to the fine grinding wheel can remove impurities on the surface of the diamond micro-powder and surface-adsorbed organic macromolecules through activation of an activator, thereby avoiding the situation that the diamond micro-powder is prematurely dropped due to the influence of the holding force caused by the impurity adsorption layer when the diamond micro-powder is used as grinding wheel abrasive. In addition, the impurity-removed diamond micro-powder can further improve the holding force through a coating material, and the dispersant can improve the dispersity of the coating material, so that a uniformly-distributed coating film can be formed on the surface of the diamond micro-powder. The coating film can hinder the diamond micro-powder from being in contact with oxygen to cause a decomposition reaction in a high-temperature environment, thereby effectively guaranteeing the strength of the diamond micro-powder when the diamond micro-powder is used as grinding wheel abrasive, and prolonging the service life of the diamond micro-powder.

Description

Technical Field

[0001] This invention relates to the field of materials technology, specifically to a clustered diamond micro powder for use in fine grinding wheels. Background Technology

[0002] Grinding wheels, also known as bonded abrasives, are abrasives made by binding ordinary abrasive grains together with a binder to form a specific shape and strength. Grinding wheels are the most widely used and extensive type of abrasive. They rotate at high speeds and can be used for roughing, semi-finishing, and finishing metal or non-metal workpieces, including outer and inner circles, planes, and various profiles, as well as for grooving and cutting. There are many types of grinding wheels. Based on the abrasive used, they can be divided into ordinary abrasive (corundum and silicon carbide, etc.) grinding wheels and natural abrasive and superhard abrasive (diamond and cubic boron nitride, etc.) grinding wheels. Abrasive grains are the main raw material for manufacturing grinding wheels, and different types of abrasives result in different grinding wheel performance and applications.

[0003] Diamond, as a superhard material with high hardness and excellent wear resistance, can be sintered with binders such as metals, ceramics, and resins. However, because the carbon atoms on the surface of diamond are in an unsaturated state, they are prone to chemical adsorption, forming an impurity adsorption layer. This affects the binding force of the binder on the diamond abrasive, easily causing the diamond abrasive to detach prematurely. Furthermore, grinding wheels generate high heat during use; above 600℃, they react with oxygen to produce carbon dioxide and carbon monoxide, i.e., graphitization, which reduces the strength of the diamond abrasive grains, thus affecting their application performance and service life. Therefore, it is necessary to improve these defects of diamond to enable its use in manufacturing fine grinding wheels. In view of this, we propose a clustered diamond micro-powder for use in fine grinding wheels. Summary of the Invention

[0004] To overcome the above deficiencies, the present invention provides a clustered diamond micro powder for use in fine grinding wheels.

[0005] The technical solution of this invention is:

[0006] A type of aggregated diamond micron powder for use in fine grinding wheels, comprising diamond micron powder abrasive, and further comprising:

[0007] A coating material that prevents the diamond micron abrasive from graphitizing at high temperatures; the coating material includes any one or more of carbon-loving metals and oxygen-absorbing metals.

[0008] A dispersant that can improve the dispersion of the coating material on the surface of the diamond micron abrasive.

[0009] Preferably, the coating material accounts for 3%-8% of the mass percentage of the diamond micron abrasive, and the dispersant accounts for 0.5%-2% of the mass percentage of the diamond micron abrasive.

[0010] Preferably, the carbophilic metal is any one or more of titanium, chromium, nickel, and tungsten.

[0011] Specifically, carbophilic metals can react with the surface of diamond micropowder to form a carbide coating film, which can effectively improve the high-temperature oxidation resistance of diamond micropowder and the holding force of resin or ceramic binders on diamond. At the same time, carbophilic metals can improve the high-temperature thermal stability of diamond, prevent its surface oxidation and graphitization, and help improve its service life.

[0012] Preferably, the oxygen-absorbing metal is any one or more of aluminum, manganese, copper, and zinc.

[0013] Specifically, oxygen-absorbing metals can form a strong bond with diamond micropowder, enabling them to aggregate during processing and forming a composite aggregate structure. This means they can form carbides with diamond micropowder, achieving metallurgical bonding. The mechanism of action of oxygen-absorbing metals is that they can preferentially react with oxygen, thereby protecting diamond micropowder from oxidation.

[0014] Preferably, the particle size of the carbonophilic metal and the oxygen-absorbing metal is 10-100 nanometers.

[0015] Preferably, the dispersant is a silane coupling agent. By using the silane coupling agent to modify the surface of the diamond micro powder with silanization, the dispersibility and anti-settling properties of the diamond micro powder in the liquid matrix can be improved, so that the coating material can be uniformly coated.

[0016] Preferably, the diamond micron abrasive has a particle size of 0.1-10 micrometers.

[0017] Preferably, the diamond micro powder abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micro powder abrasive.

[0018] Specifically, diamond is a typical covalently bonded atomic crystal, with carbon atoms arranged in sp2 phases. 3 Hybridization occurs when each carbon atom forms four covalent bonds with four surrounding carbon atoms arranged in a tetrahedral pattern, creating a three-dimensional network structure. Inside the diamond, each carbon atom is connected to four adjacent carbon atoms by hybrid orbitals, forming covalent bonds and reaching a saturated state. However, the carbon atoms in the surface layer have residual bonds and are in an unsaturated state, making them prone to chemisorption. There is always a layer of adsorbed impurities on the diamond surface. If this adsorbed layer is not removed, the inclusions in the surface adsorbed layer will severely affect the binding force of the binder on the diamond micro-powder abrasive during the subsequent preparation of the grinding wheel, causing the diamond micro-powder abrasive to fall off prematurely.

[0019] Preferably, the activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide. The alkaline aqueous solution prepared with 20 g / L of analytical grade sodium hydroxide and 10 g / L of analytical grade sodium carbonate can initially remove impurities such as oil stains adhering to the surface of diamond micropowder. The acid treatment solution prepared with analytical grade concentrated nitric acid and analytical grade hydrogen peroxide can effectively destroy and remove impurities on the surface of diamond micropowder and impurities such as adsorbed organic macromolecules due to the strong corrosive effect of concentrated nitric acid and the strong oxidizing effect of hydrogen peroxide. This makes the surface of diamond micropowder exhibit good hydrophilicity and can be uniformly dispersed in the precipitation solution, further ensuring the uniformity of subsequent coating.

[0020] Preferably, the volume ratio of the analytical grade concentrated nitric acid to the analytical grade hydrogen peroxide is 1:0.2-0.5.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This clustered diamond micropowder, used in fine grinding wheels, can remove impurities and adsorbed organic macromolecules from the surface of the diamond micropowder through activation by an activator. This prevents the diamond micropowder from prematurely detaching when used as an abrasive due to reduced holding power caused by the impurity adsorption layer. In addition, the impurity-removed diamond micropowder can further improve the holding power through a coating material. The dispersant improves the dispersion of the coating material, allowing it to form a uniformly distributed coating film on the surface of the diamond micropowder. This coating film can prevent the diamond micropowder from decomposing due to contact with oxygen in a high-temperature environment, thus effectively ensuring the strength of the diamond micropowder as an abrasive and giving it a longer service life. Attached Figure Description

[0023] Figure 1 This is one of the metallographic images of the present invention;

[0024] Figure 2 This is the second metallographic image of the present invention;

[0025] Figure 3 This is the third metallographic image of the present invention; Detailed Implementation

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

[0027] Example 1

[0028] The present invention will describe the above technical solution in detail through the following embodiments:

[0029] A type of aggregated diamond micron powder for use in fine grinding wheels, comprising diamond micron powder abrasive, and further comprising:

[0030] The coating material can prevent the diamond micro powder abrasive from graphitizing at high temperatures. The coating material uses a carbon-loving metal and an oxygen-absorbing metal. The carbon-loving metal is 100-nanometer titanium powder, and the oxygen-absorbing metal is 100-nanometer aluminum powder.

[0031] Dispersant: The dispersant can improve the dispersion of the coating material on the surface of diamond micron abrasive. The dispersant is a silane coupling agent, specifically 98% pure tetraethyl orthosilicate.

[0032] The coating material accounts for 8% of the mass of the diamond micro powder abrasive, and tetraethyl orthosilicate accounts for 2% of the mass of the diamond micro powder abrasive. The particle size of the diamond micro powder abrasive is 5 micrometers.

[0033] Diamond micro powder abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micro powder abrasive.

[0034] The activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide; the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide is 1:0.4.

[0035] This embodiment describes the application of clustered diamond micropowder in fine grinding wheels. The specific modification process of the diamond micropowder is as follows: First, 20g of analytical grade sodium hydroxide and 10g of analytical grade sodium carbonate are weighed and dissolved in 1L of distilled water to prepare a first mixed solution. Then, 1L of a second mixed solution is prepared according to the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide of 1:0.4. Subsequently, 50g of diamond micropowder is mixed into the first mixed solution, stirred for 30 minutes, and then washed with water until neutral. The second mixed solution is then added again, stirred for 30 minutes, and then washed with water until neutral for later use. Next, the raw materials are weighed according to the mass percentage of this embodiment, and the weighed raw materials are processed... The chemically treated diamond micropowder was placed in a mixed solution of 3 mol / L urea and 0.1 mol / L Zn(NO3)2, and a coating material and tetraethyl orthosilicate were added simultaneously. After heating to 100°C and stirring for 2 hours, stirring was stopped to allow precipitation. Finally, the precipitate was separated from the supernatant by filtration. The precipitate was then placed in a high-temperature furnace and sintered at 300°C for 2 hours. During the sintering process, the oxygen-absorbing metal formed a strong bond with the diamond micropowder and was able to form carbides with the diamond micropowder, resulting in clustered diamond micropowder for grinding wheels. This achieved metallurgical bonding, and the surface of the diamond micropowder was coated after sintering.

[0036] Example 2

[0037] The present invention will describe the above technical solution in detail through the following embodiments:

[0038] A type of aggregated diamond micron powder for use in fine grinding wheels, comprising diamond micron powder abrasive, and further comprising:

[0039] The coating material can prevent the diamond micro powder abrasive from graphitizing at high temperatures. The coating material uses a carbon-loving metal and an oxygen-absorbing metal. The carbon-loving metal is 100-nanometer titanium powder, and the oxygen-absorbing metal is 100-nanometer aluminum powder.

[0040] Dispersant: The dispersant can improve the dispersion of the coating material on the surface of diamond micron abrasive. The dispersant is a silane coupling agent, specifically 98% pure tetraethyl orthosilicate.

[0041] The coating material accounts for 5% of the mass of the diamond micro powder abrasive, and tetraethyl orthosilicate accounts for 1.2% of the mass of the diamond micro powder abrasive. The particle size of the diamond micro powder abrasive is 5 micrometers.

[0042] Diamond micro powder abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micro powder abrasive.

[0043] The activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide; the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide is 1:0.4.

[0044] The diamond micropowder used in this embodiment for fine grinding wheels undergoes the following modification process: First, 20g of analytical grade sodium hydroxide and 10g of analytical grade sodium carbonate are mixed and dissolved in 1L of distilled water to prepare a first mixed solution. Then, 1L of a second mixed solution is prepared according to a volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide of 1:0.4. Subsequently, 50g of diamond micropowder is mixed into the first mixed solution, stirred for 30 minutes, and then washed with water until neutral. The second mixed solution is then added and stirred for another 30 minutes, and then washed with water until neutral for later use. Next, the raw materials are weighed according to the mass percentage of this embodiment. The activated diamond micropowder is placed in a mixed solution of 3mol / L urea and 0.1mol / L Zn(NO3)2, and a coating material and tetraethyl orthosilicate are added simultaneously. The mixture is heated to 100°C and stirred for 2 hours. After stirring, the mixture is stopped to allow precipitation. Finally, the precipitate and supernatant are filtered and separated. The precipitate is then placed in a high-temperature furnace and sintered at 300°C for 2 hours to obtain diamond micropowder with a surface coating.

[0045] Example 3

[0046] The present invention will describe the above technical solution in detail through the following embodiments:

[0047] A type of aggregated diamond micron powder for use in fine grinding wheels, comprising diamond micron powder abrasive, and further comprising:

[0048] The coating material can prevent the diamond micro powder abrasive from graphitizing at high temperatures. The coating material uses a carbon-loving metal and an oxygen-absorbing metal. The carbon-loving metal is 100-nanometer titanium powder, and the oxygen-absorbing metal is 100-nanometer aluminum powder.

[0049] Dispersant: The dispersant can improve the dispersion of the coating material on the surface of diamond micron abrasive. The dispersant is a silane coupling agent, specifically 98% pure tetraethyl orthosilicate.

[0050] The coating material accounts for 3% of the mass of the diamond micro powder abrasive, and tetraethyl orthosilicate accounts for 0.5% of the mass of the diamond micro powder abrasive. The particle size of the diamond micro powder abrasive is 5 micrometers.

[0051] Diamond micro powder abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micro powder abrasive.

[0052] The activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide; the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide is 1:0.4.

[0053] The diamond micropowder used in this embodiment for fine grinding wheels undergoes the following modification process: First, 20g of analytical grade sodium hydroxide and 10g of analytical grade sodium carbonate are mixed and dissolved in 1L of distilled water to prepare a first mixed solution. Then, 1L of a second mixed solution is prepared according to the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide of 1:0.4. Subsequently, 50g of diamond micropowder is mixed into the first mixed solution, stirred for 30 minutes, and then washed with water until neutral. The second mixed solution is then added and stirred for another 30 minutes, and then washed with water until neutral for later use. Next, the raw materials are weighed according to the mass percentage of this embodiment. The activated diamond micropowder is placed in a mixed solution of 3mol / L urea and 0.1mol / L Zn(NO3)2, and a coating material and tetraethyl orthosilicate are added simultaneously. The mixture is heated to 100°C and stirred for 2 hours. After stirring, the mixture is stopped to allow precipitation. Finally, the precipitate and supernatant are filtered and separated. The precipitate is then placed in a high-temperature furnace and sintered at 300°C for 2 hours to obtain diamond micropowder with a surface coating.

[0054] Comparative Example 1

[0055] The present invention will describe the above technical solution in detail through the following embodiments:

[0056] A type of aggregated diamond micron powder for use in fine grinding wheels, comprising diamond micron powder abrasive, and further comprising:

[0057] The coating material can prevent the diamond micro powder abrasive from graphitizing at high temperatures. The coating material uses a carbon-loving metal and an oxygen-absorbing metal. The carbon-loving metal is 100-nanometer titanium powder, and the oxygen-absorbing metal is 100-nanometer aluminum powder.

[0058] The coating material accounts for 8% of the mass of the diamond micro powder abrasive, and the particle size of the diamond micro powder abrasive is 5 micrometers.

[0059] Diamond micro powder abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micro powder abrasive.

[0060] The activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide; the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide is 1:0.4.

[0061] The diamond micropowder used in this embodiment for fine grinding wheels undergoes the following modification process: First, 20g of analytical grade sodium hydroxide and 10g of analytical grade sodium carbonate are mixed and dissolved in 1L of distilled water to prepare a first mixed solution. Then, 1L of a second mixed solution is prepared according to a volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide of 1:0.4. Subsequently, 50g of diamond micropowder is mixed into the first mixed solution, stirred for 30 minutes, and then washed with water until neutral. The second mixed solution is then added and stirred for another 30 minutes, and then washed with water until neutral for later use. Next, the raw materials are weighed according to the mass percentage of this embodiment. The activated diamond micropowder is placed in a mixed solution of 3mol / L urea and 0.1mol / L Zn(NO3)2, and a coating material is added simultaneously. The mixture is heated to 100°C and stirred for 2 hours. Then, stirring is stopped to allow precipitation. Finally, the precipitate and supernatant are filtered and separated. The precipitate is then placed in a high-temperature furnace and sintered at 300°C for 2 hours to obtain diamond micropowder with a surface coating.

[0062] Comparative Example 2

[0063] The present invention will describe the above technical solution in detail through the following embodiments:

[0064] A type of aggregated diamond micron powder for use in fine grinding wheels, comprising diamond micron powder abrasive, and further comprising:

[0065] The dispersant improves the dispersion of the coating material on the surface of the diamond micro powder abrasive. The dispersant is a silane coupling agent, specifically 98% pure tetraethyl orthosilicate, and the tetraethyl orthosilicate accounts for 2% of the mass of the diamond micro powder abrasive. The particle size of the diamond micro powder abrasive is 5 micrometers.

[0066] Diamond micro powder abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micro powder abrasive.

[0067] The activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide; the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide is 1:0.4.

[0068] The diamond micropowder used in this embodiment for fine grinding wheels undergoes the following modification process: First, 20g of analytical grade sodium hydroxide and 10g of analytical grade sodium carbonate are mixed and dissolved in 1L of distilled water to prepare a first mixed solution. Then, 1L of a second mixed solution is prepared according to a volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide of 1:0.4. Subsequently, 50g of diamond micropowder is mixed into the first mixed solution, stirred for 30 minutes, and then washed with water until neutral. The second mixed solution is then added and stirred for another 30 minutes, and then washed with water until neutral for later use. Next, the raw materials are weighed according to the mass percentage of this embodiment. The activated diamond micropowder is placed in a mixed solution of 3mol / L urea and 0.1mol / L Zn(NO3)2, and tetraethyl orthosilicate is added simultaneously. The mixture is heated to 100°C and stirred for 2 hours. Then, stirring is stopped to allow precipitation. Finally, the precipitate and supernatant are filtered and separated. The precipitate is then placed in a high-temperature furnace and sintered at 300°C for 2 hours to obtain diamond micropowder with a surface coating.

[0069] The difference between Examples 1-3 lies in the different amounts of coating material and dispersant added, while all other conditions are the same; the difference between Comparative Example 1 and Example 1 is that no dispersant was added; the difference between Comparative Example 2 and the Examples is that no coating material was added; grinding wheel samples were prepared according to the diamond micro powder of Examples 1-3, Comparative Example 1, and Comparative Example 2, respectively. The degree of dispersion on the sample surface was observed by SEM scanning electron microscopy, and the surface coating was observed by TEM transmission electron microscopy.

[0070] Example 1 Fully coated surface Evenly dispersed Example 2 The surface is fully coated, and the particle diameter is small. Evenly dispersed Example 3 The surface is fully coated, and the particle diameter is small. Small particle aggregation Comparative Example 1 Fully coated surface Significant accumulation of microparticles Comparative Example 2 Surface uncoated Evenly dispersed

[0071] Observations show that the diamond micropowders in Examples 1, 2, and Comparative Example 1 are uniformly dispersed with similar degrees of dispersion. As the dispersant content decreases, accumulation gradually occurs. In Example 3, only a small amount of aggregation was observed without any apparent accumulation, while Comparative Example 2 exhibits a lower degree of dispersion. Furthermore, the addition of coating material affects the particle diameter; a larger diameter indicates a thicker coating. Comparative Example 2 has no coating. Therefore, the main factor affecting the dispersion of diamond micropowder is the dispersant, and the main factor affecting the formation and thickness of the coating is the coating material. Based on the above experimental data, Example 1 is preferred. Figure 1 , Figure 2 , Figure 3 The image shown is a metallographic diagram of Example 1.

[0072] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A type of aggregated diamond micro powder for use in fine grinding wheels, comprising diamond micro powder abrasive, characterized in that: Also includes: The coating material and dispersant, wherein the coating material includes any one or more of a carbophilic metal and an oxygen-absorbing metal, wherein the particle size of the carbophilic metal and the oxygen-absorbing metal is 10-100 nanometers, and the particle size of the diamond micron abrasive is 0.1-10 micrometers; The coating material accounts for 3%-8% of the mass of the diamond micron abrasive, and the dispersant accounts for 0.5%-2% of the mass of the diamond micron abrasive; the carbonophilic metal is any one or more of titanium, chromium, nickel, and tungsten; the oxygen-absorbing metal is any one or more of aluminum, manganese, copper, and zinc; the dispersant is a silane coupling agent; the diamond micron abrasive uses diamond activated by an activator as raw material, which can remove the impurity adsorption layer on the surface of the diamond micron abrasive; The activation process is as follows: First, weigh 20g of analytical grade sodium hydroxide and 10g of analytical grade sodium carbonate and dissolve them in 1L of distilled water to prepare the first mixed solution. Then, prepare 1L of the second mixed solution according to the volume ratio of analytical grade concentrated nitric acid to analytical grade hydrogen peroxide of 1:0.

4. Then, mix 50g of diamond micro powder into the first mixed solution, stir for 30 minutes, take it out and wash it with water until neutral, continue to add the second mixed solution and stir for 30 minutes, take it out and wash it with water until neutral for later use. Weigh the raw materials according to the mass percentage, put the activated diamond micro powder into a mixed solution of 3 mol / L urea and 0.1 mol / L Zn(NO3)2, and simultaneously add the coating material and tetraethyl orthosilicate. After heating to 100°C and stirring for 2 hours, stop stirring to allow precipitation. Finally, filter and separate the precipitate from the supernatant. Place the precipitate in a high-temperature furnace and sinter at 300°C for 2 hours to obtain the surface-coated clustered diamond micro powder for grinding wheels.

2. The clustered diamond micron powder for use in fine grinding wheels as described in claim 1, characterized in that: The activator includes 20 g / L of analytical grade sodium hydroxide, 10 g / L of analytical grade sodium carbonate, analytical grade concentrated nitric acid, and analytical grade hydrogen peroxide.

Images