Superhard abrasive tool with free smelting ceramic bond and preparation method and application thereof

Abstract

The application provides a superhard abrasive tool free smelting ceramic binder and a preparation method and application thereof, which is composed of silica, alumina, boric oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate and rare earth oxide in specific proportions. The ceramic binder does not need to be cooled and broken after smelting, and through the interaction and reaction among the raw materials, glass is generated under certain conditions, and ceramic nanocrystals with different shapes and sizes are contained inside, so that the obtained binder has good mechanical strength, grinding performance and binding force, and is used for the preparation of superhard ceramic abrasive tools, and the superhard ceramic abrasive tools with high strength, good toughness, good sharpness and long service life can be obtained. The ceramic binder provided by the application has a simple preparation method, the smelting step of the conventional superhard abrasive tool binder is omitted, and the preparation cost is reduced. The superhard abrasive tool binder prepared by the application has not been reported.

Description

Technical Field

[0001] This invention belongs to the technical field of ceramic binders, and in particular relates to a non-melting ceramic nano-binder suitable for the superhard abrasive industry, its preparation method, and its application. Background Technology

[0002] Existing superhard ceramic abrasives often require ceramic binder powder that has been melted at high temperatures, as the melted ceramic binder provides better wetting of the abrasive. Existing technology discloses a low-temperature ceramic-bonded diamond grinding wheel and its preparation method, belonging to the field of superhard abrasive manufacturing technology; the initial ceramic binder material is obtained by ball milling, melting, water quenching, ball milling again, drying, and sieving. Existing technology also discloses a method for preparing crystallized ceramic-bonded abrasives, in which a certain proportion of raw materials are mixed, melted, cooled, pulverized, and ball-milled uniformly; the resulting mixed powder is then added to a solvent and dispersed uniformly with a surfactant; then tetraethyl orthosilicate is added and stirred to react; the mixture is spray-dried; and finally microwave-treated to obtain a crystallized ceramic binder. Existing technology provides a polycrystalline microcrystalline glass-ceramic binder with high strength and reliable wear resistance. The sieved mixture is placed in an oven and baked at 120-150℃ for 1-2 hours, then melted in a converter at a heating rate of 5-7℃ / min to a high temperature of 1320-1400℃, and held at that temperature for 1-2 hours. Existing technology also discloses a porous ceramic binder and its preparation method. The preparation method includes mixing, melting and quenching, ball milling, and sieving. This invention has a simple process and readily available raw materials. The research progress on ceramic binders for diamond abrasives discloses a glass material preparation process that involves first determining the formula and preparing the corresponding raw materials, then weighing, mixing, melting, water quenching, grinding to below 80μm, and drying to a moisture content of less than 5% for later use. Existing technologies have selected a borosilicate glass system as the base system for ceramic binders, determined the components of the binder, and finally obtained the ceramic binder through processes such as weighing and mixing, high-temperature melting, water quenching and drying, ball milling and sieving.

[0003] Traditional ceramic binder preparation requires high-temperature melting to improve binder performance, enhance its wetting effect on abrasives, and ultimately improve abrasive performance. This is common knowledge in the field, but the melting process for binder preparation consumes a lot of energy and resources. Summary of the Invention

[0004] This invention provides a ceramic binder that eliminates the need for high-temperature smelting, reducing energy consumption and production costs, thus achieving green production, energy conservation, and emission reduction. The preparation method is simple, efficient, and low-cost. Furthermore, this binder is a ceramic binder containing a large number of nanocrystals of different shapes and sizes. Abrasives prepared with this binder exhibit good mechanical strength and sharpness.

[0005] The present invention adopts the following technical solution:

[0006] A method for preparing a ceramic binder includes the following steps: mixing raw materials to obtain the ceramic binder; the raw materials include one or more of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides. Preferably, the ceramic binder is composed of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides.

[0007] In this invention, silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides are mixed to prepare a ceramic binder without smelting; preferably, silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides are ball-milled to prepare the ceramic binder; even more preferably, silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides are ball-milled, dried, and sieved to prepare the ceramic binder.

[0008] In this invention, the rare earth oxides include lanthanum oxide and cerium oxide; preferably, the rare earth oxides are lanthanum oxide and cerium oxide; more preferably, the weight ratio of lanthanum oxide and cerium oxide is 1:(0.5-1.5), and more preferably 1:(0.9-1.3).

[0009] In this invention, the proportions of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides by weight are (300-500):(10-50):(300-400):(30-80):(10-30):(5-15):(30-80):(10-50):(50-100):(5-20); preferably, the proportions of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides are (350-450):(20-100):(5-20). 40): (320-380): (40-60): (15-25): (7-13): (40-60): (20-40): (70-90): (7-15); More preferably, the ratio of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxide is (380-420): (25-35): (330-360): (45-55): (17-22): (8-12): (45-55): (25-35): (75-85): (8-12).

[0010] In this invention, during ball milling, the material-to-ball-to-water ratio is 1:(1-3):(0.1-2), preferably 1:(1-2):(0.2-1), for example, 1:1.5:0.5; the ball milling time is 1-48 hours, preferably 20-40 hours. The drying temperature is 80-200℃, preferably 120-180℃; the drying time is 5-24 hours, preferably 15-20 hours. After sieving, the material with a particle size of 10-30 μm is used as the ceramic binder of this invention.

[0011] A superhard abrasive tool comprising a ceramic bond and an abrasive.

[0012] The preparation method of the above-mentioned superhard abrasive includes the following steps: mixing abrasive, ceramic binder and resin liquid, molding, drying and sintering to obtain superhard abrasive.

[0013] Preferably, the abrasive includes CBN abrasive; the resin liquid is a common commercially available phenolic resin liquid, which mixes and molds the abrasive binder.

[0014] Preferably, the weight ratio of abrasive, ceramic binder and resin liquid is (65-85):(15-20):(3-5), more preferably (70-85):(15-18):(4-5), such as 80:15:5.

[0015] This invention discloses the application of the above-mentioned ceramic binder in the preparation of superhard abrasives, such as the preparation of CBN abrasives, which have good mechanical strength, strong abrasive holding force, good sharpness, long service life, and the preparation method is simple.

[0016] This invention discloses the application of the aforementioned superhard abrasives, such as CBN abrasives, in the machining of the inner diameter of compressors.

[0017] Compared with existing technologies, the ceramic binder and its preparation method provided by this invention have the following advantages:

[0018] The ceramic binder provided by this invention is composed of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides in a specific range of proportions. The rare earth oxides include lanthanum oxide and cerium oxide. This ceramic binder does not require melting; it generates a glassy substance under certain conditions through the interaction and reaction between the raw materials. The substance contains ceramic nanocrystals of different shapes and sizes. The resulting binder exhibits good mechanical strength, grinding performance, and bonding force. When used in the preparation of superhard ceramic abrasives, it can produce superhard ceramic abrasives with high strength, good toughness, good sharpness, and long service life.

[0019] The ceramic binders used in conventional abrasives are composed of mineral raw materials such as clay, quartz, and feldspar, and are generally fired at temperatures above 1200℃, making them unsuitable for applications such as the inner and outer diameters and end faces of compressors. Due to the temperature sensitivity of diamond and CBN, superhard abrasives are generally fired at temperatures below 950℃, and the ceramic binders used are mostly formulated through the melting and refining of chemically pure compounds. The ceramic binder preparation method provided by this invention is simple, overcoming the technical bias in existing technologies that require a melting and refining step for superhard abrasive binders, and reducing preparation costs.

[0020] The CBN abrasive provided by this invention has high strength, good sharpness, long service life, and requires less binder. The preparation method of the CBN abrasive provided by this invention is low in cost. Attached Figure Description

[0021] Figure 1 This is a scanned electronic photograph of the non-melting ceramic CBN abrasive tool of Embodiment 2 of the present invention.

[0022] Figure 2 An optical photograph of a compressor cylinder workpiece machined by a superhard grinding wheel according to Embodiment 2 of the present invention. Detailed Implementation

[0023] The embodiments and examples of the present invention will be described in detail below. However, those skilled in the art will understand that the following embodiments and examples are for illustrative purposes only and should not be considered as limiting the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specified, conventional conditions or conditions recommended by the manufacturer shall apply. The raw materials involved in the present invention are all commercially available products that meet the conventional application requirements of superhard grinding wheels. Those skilled in the art can obtain suitable raw materials without creative effort.

[0024] This invention provides a ceramic binder, which is prepared by ball milling, drying, and sieving silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides. The ratio of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides by weight is (300-500):(10-50):(300-400):(30-80):(10-30):(5-15):(30-80):(10-50):(50-100):(5-20).

[0025] In this invention, a specific ratio of conventional metal oxides combined with rare earth metal oxides is used to lower the glass transition temperature of the binder. This allows the binder raw materials to be used immediately after being proportioned, without the need for smelting. The particle size of the ceramic binder is 10–30 μm. In this invention, the binder containing specific proportions of zirconium silicate, boron oxide, rare earth oxides, and other components reacts with each other, promoting the precipitation of crystals in the binder during the grinding wheel sintering process. This improves the mechanical strength and grinding performance of the binder, thereby enhancing the strength, sharpness, and service life of the grinding wheel.

[0026] As an example, this invention provides a method for preparing a CBN abrasive, comprising the following steps: first, mixing the formulated amounts of CBN abrasive, ceramic binder, and resin liquid; then, cold-pressing and drying the mixture; and finally, sintering it to obtain the CBN abrasive. The mixing time is 10-45 min, preferably 25 min; the density of the CBN obtained by molding is 2-2.5 g / cm³. 3 Preferred concentration: 2.5g / cm 3 The drying temperature is 150℃, and the drying time is 5-12h, preferably 8h; the sintering temperature is 750-950℃, preferably 900℃; the sintering heating rate is 30-65℃ / h, preferably 30℃ / h; the sintering holding time is 1-3h, preferably 2h.

[0027] This invention provides the application of the above-mentioned CBN abrasive in machining the inner circle of a compressor; preferably, the inner circle of the compressor is the inner circle of an air conditioning compressor.

[0028] Example 1

[0029] A ceramic binder is composed of the following components: 400g silicon oxide, 30g aluminum oxide, 350g boron oxide, 50g sodium carbonate, 20g lithium carbonate, 10g calcium oxide, 50g magnesium oxide, 30g zinc oxide, 80g zirconium silicate, 5g lanthanum oxide, and 6g cerium oxide.

[0030] The preparation method of the above-mentioned ceramic binder is as follows:

[0031] (1) Mixing: Take the above materials and ball mill them in a ball mill with a material-to-water ratio of 1:1.5:0.5 and ball mill at 800 rpm for 36 hours.

[0032] (2) Keep the ball-milled material in a drying oven at 150℃ for 18 hours;

[0033] (3) After drying, the material is sieved through a screen and the powder with a particle size of 10-30 μm is obtained to obtain the ceramic binder; the whole process does not require smelting.

[0034] Example 2

[0035] A CBN abrasive tool, the raw materials are as follows: 80g of CBN abrasive, 15g of ceramic binder provided in Example 1 and 5g of phenolic resin liquid.

[0036] The preparation method is as follows:

[0037] (1) Mixing: Stir and mix the CBN abrasive, ceramic binder and resin liquid evenly for 25 minutes;

[0038] (2) Molding: The mixture from step (1) is cold-pressed in a mold to a density of 2.5 g / cm³. 3 The mold specifications are: 1A8 35×33×66×M12 CBN140 N200 45 m / s;

[0039] (3) Drying: Dry the CBN grinding wheel formed in step (2) in an oven at a temperature of 150°C for 8 hours.

[0040] (4) Sintering: Place the dried CBN grinding wheel from step (3) in a muffle furnace for sintering. The heating rate is 30℃ / h, from room temperature to 900℃, and hold for 2h. Then, allow it to cool naturally to room temperature to obtain the CBN abrasive. See the scanning electron microscope image for details. Figure 1 .

[0041] Example 3

[0042] The difference from Example 1 is that the raw material composition is: 350g silicon oxide, 40g aluminum oxide, 320g boron oxide, 60g sodium carbonate, 25g lithium carbonate, 12g calcium oxide, 60g magnesium oxide, 20g zinc oxide, 70g zirconium silicate, 10g lanthanum oxide, and 5g cerium oxide.

[0043] Example 4

[0044] The difference from Example 1 is that the raw material composition is: 450g silicon oxide, 20g aluminum oxide, 380g boron oxide, 40g sodium carbonate, 15g lithium carbonate, 8g calcium oxide, 40g magnesium oxide, 40g zinc oxide, 90g zirconium silicate, 4g lanthanum oxide, and 5g cerium oxide.

[0045] Example 5

[0046] The difference from Example 1 is that the raw material composition does not include boron oxide and zirconium silicate, but the rest is the same.

[0047] Example 6

[0048] The difference from Example 1 is that the raw material composition does not contain boron oxide, but the rest is the same.

[0049] Example 7

[0050] The difference from Example 1 is that the raw material composition does not contain zirconium silicate, but the rest is the same.

[0051] Comparison Example

[0052] A type of existing ceramic binder CBN abrasive is currently the best performing product of its kind in industrial production, and is a smelting ceramic binder.

[0053] Comparative Example 1

[0054] The difference from Example 2 is that the ceramic binder used is the one prepared in Example 5, but the rest are the same.

[0055] Test case

[0056] The grinding wheels of the examples and comparative examples were used as inner grinding wheels for air conditioning compressors, and parallel experiments were conducted. The specific performance test results are shown in Table 1. The roughness and roundness are the results within the dressing interval.

[0057]

[0058] Figure 2The image shows a workpiece processed by the CBN abrasive tool in Example 2. The results are excellent and meet customer requirements. From the above actual performance results, it can be seen that the ceramic CBN abrasive tool made with the non-melting ceramic binder provided by this invention not only meets processing requirements but also, compared to existing CBN abrasive tools, has a faster processing cycle, longer dressing intervals and service life, and better processing stability.

[0059] Comparative Example 2

[0060] The difference from Example 2 is that the ceramic binder used is the one provided in Example 6; otherwise, they are the same. The grinding wheel prepared by holding at 900℃ for 2 hours has low hardness, significantly lower than that of existing ceramic-bonded CBN abrasives, and is not suitable for processing experiments.

[0061] Comparative Example 3

[0062] The difference from Example 2 is that the ceramic binder used is the one provided in Example 7, and the rest is the same. After sintering, the grinding wheel cracked because the relative content of boron oxide in the formula increased, the coefficient of thermal expansion increased, the thermal shock resistance decreased, and the number of crystalline phases obtained was less, which increased the brittleness of the grinding wheel. The present invention creatively adds an appropriate amount of zirconium silicate to the formula, which promotes the precipitation of a large number of crystalline phases during the sintering process, thus solving the problem of cracking of the grinding wheel prepared by the non-melting binder in Example 7.

[0063] Example 8

[0064] A ceramic binder is composed of the following components: 410g silicon oxide, 25g aluminum oxide, 330g boron oxide, 55g sodium carbonate, 18g lithium carbonate, 8g calcium oxide, 45g magnesium oxide, 35g zinc oxide, 75g zirconium silicate, 5g lanthanum oxide, and 5g cerium oxide.

[0065] Example 9

[0066] A ceramic binder is composed of the following components: 380g silicon oxide, 35g aluminum oxide, 360g boron oxide, 45g sodium carbonate, 220g lithium carbonate, 12g calcium oxide, 55g magnesium oxide, 25g zinc oxide, 85g zirconium silicate, 6g lanthanum oxide, and 6g cerium oxide.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

[0068] Ceramic binders are silicate glass materials with a certain degree of brittleness. Superhard ceramic abrasives are prone to breakage during use. While they possess good sharpness, existing ceramic-bonded abrasives have limitations in applications requiring high strength and high grip, leading to short lifespans and substandard workpiece quality. This invention prepares a non-melting ceramic binder. By limiting the material ratio and formula, the step of melting to prepare the nano-ceramic binder is eliminated, significantly reducing production costs and energy consumption, resulting in superior application value. Furthermore, the prepared grinding wheels exhibit better processing performance than existing products.

Claims

1. A method for preparing a ceramic binder, comprising the following steps: mixing raw materials to obtain a ceramic binder; wherein the raw materials are composed of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides; the rare earth oxides include lanthanum oxide and cerium oxide; the ratio of silicon oxide, aluminum oxide, boron oxide, sodium carbonate, lithium carbonate, calcium oxide, magnesium oxide, zinc oxide, zirconium silicate, and rare earth oxides by weight is (300-500):(10-50):(300-400):(30-80):(10-30):(5-15):(30-80):(10-50):(50-100):(5-20); no melting is required when preparing the ceramic binder.

2. The ceramic binder prepared by the method of preparing the ceramic binder according to claim 1.

3. A method for preparing a superhard abrasive, comprising the following steps: mixing abrasive, the ceramic binder described in claim 2 and resin liquid, followed by molding, drying and sintering to obtain a superhard abrasive; the weight ratio of abrasive, ceramic binder and resin liquid is (65-85):(15-20):(3-5).

4. The superhard abrasive prepared by the method for preparing superhard abrasives according to claim 3.

5. The application of the superhard abrasive as described in claim 4 in the machining of the inner circle of a compressor.

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