Super essential oil stone and preparation method thereof

Abstract

The invention relates to the technical field of ultra-fine oilstones, in particular to an ultra-fine oilstone and a preparation method thereof.The preparation method comprises the steps that calcined and KH-570 modified diatomite is dispersed in water, a monomer N-isopropylacrylamide, a free radical initiator and an accelerant TEMED are added, the mixture is stirred and reacted for 1-10 h at the room temperature, sediment is filtered out, the sediment is leached with cold water and then dispersed in a polyethylene glycol aqueous solution, and the ultra-fine oilstone is obtained; and then adding the grinding material and the glass powder, heating to 40-60 DEG C, stirring and mixing for 10-60 minutes, filtering, pressing and drying the obtained solid in a mold, and finally sintering.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of super-fine oil stone, in particular to a super-fine oil stone and a preparation method thereof. BACKGROUND

[0002] The super-fine oil stone is a new type of polishing material developed in recent years, which is composed of abrasive and binder, and is particularly suitable for super-finishing of bearing grooves, and can efficiently obtain a surface with high smoothness, uniform texture and mirror-like surface. Generally speaking, the higher the hardness of the polishing material, the more difficult the abrasive particles fall off from the surface, and the smaller the consumption during grinding. However, in the super-finishing of bearing grooves, the pores play a role in chip containment, chip removal and cooling during grinding. Therefore, the super-fine oil stone requires a certain porosity and a certain hardness, which is a contradictory problem. How to ensure uniform distribution of internal pores after sintering, maintain the use performance while still maintaining high hardness, and realize the unity of super-long service life and excellent super-fine grinding finishing effect has become a problem to be solved. SUMMARY

[0003] The present application provides a super-fine oil stone and a preparation method thereof.

[0004] The technical scheme adopted is as follows: A preparation method of a super-fine oil stone, specifically as follows: The diatomite modified by calcination and KH-570 is dispersed in water, monomer N-isopropyl acrylamide, free radical initiator and accelerator TEMED (N,N,N',N'-tetramethyl ethylenediamine) are added, and after stirring at room temperature for 1-10 h, the precipitate is filtered out, washed with cold water and then dispersed in a polyethylene glycol aqueous solution. Subsequently, the abrasive and glass powder are added, and after stirring and mixing at 40-60℃ for 10-60 min, the obtained solid is filtered. The solid is pressed in a mold, dried, and finally sintered.

[0005] Further, the preparation method of the super-fine oil stone is as follows: The diatomite is heated and calcined, and after cooling to room temperature, a mixed solution of anhydrous ethanol / water is added, the pH is adjusted to 4, and the mixture is dispersed by water bath stirring. Then, silane coupling agent KH-570 is added, and after continuous stirring and reaction, the mixture is filtered and dried to obtain modified diatomite. The modified diatomite is added to water and dispersed by ultrasonic vibration. Under stirring, monomer N-isopropyl acrylamide, free radical initiator KPS and accelerator TEMED are added, and after stirring and reaction, the precipitate is filtered out, washed with cold water and then dispersed in a polyethylene glycol aqueous solution. Subsequently, the abrasive and glass powder are added, and after stirring and mixing, the obtained solid is filtered. The solid is pressed and formed in a mold and dried, and finally sintered in a muffle furnace.

[0006] Further, the calcination temperature of the diatomite is 400-500℃.

[0007] Further, the abrasive is silicon carbide.

[0008] Further, the glass powder is SiO2-B2O3-Al2O3-Sm2O3 glass powder.

[0009] Further, the SiO2-B2O3-Al2O3-Sm2O3 glass powder is prepared by the following method: SiO2, H3BO3, Al2O3 and Sm2O3 are mixed and ground, then heated to 400-600 DEG C and kept for 1-5 hours, then heated to 800-1000 DEG C and kept for 1-5 hours, and finally heated to 1200-1300 DEG C and kept for 1-5 hours, then the molten glass liquid is immersed in deionized water for water quenching, the water-quenched glass is ground into powder, and dried.

[0010] Further, the mass ratio of SiO2, H3BO3, Al2O3 and Sm2O3 is 20-25:50-60:10-15:1-5.

[0011] Further, the mass ratio of the abrasive, the glass powder and diatomite is 1:0.05-0.1:0.1-0.15.

[0012] Further, the pressure during pressing is 10-50 MPa.

[0013] Further, the temperature during sintering is 800-900 DEG C.

[0014] The application further provides an ultra-fine oil stone prepared by the above method.

[0015] The application has the following advantages: The present application provides a kind of super fine oil stone, diatomite has nanoscale pore inside, pore can be retained or enlarged in sintering process, so it can be used as pore forming agent in the preparation process of super fine oil stone, the present application is grafted on the surface and inside of diatomite by calcining and KH-570 modification, and double bond is grafted on the surface and inside of diatomite, and it is used as crosslinking agent and N-isopropyl acrylamide copolymerization, so that diatomite is loaded with poly N-isopropyl acrylamide, poly N-isopropyl acrylamide has temperature sensitive characteristics, when lower than critical solution temperature, poly N-isopropyl acrylamide molecular chain is hydrophilic and stretched, occupies larger space, when higher than critical solution temperature, poly N-isopropyl acrylamide molecular chain is hydrophobic and shrinks and gathers, and forms dense block.In 40-60 DEG C stirring mixing, poly N-isopropyl acrylamide in diatomite interior shrinks sharply, and uniform cavity structure is formed, and the shrinkage degree of poly N-isopropyl acrylamide can also be accurately controlled by temperature, when sintering, poly N-isopropyl acrylamide is finally decomposed, and high porosity, small pore diameter and uniform distribution of dispersed micropore are left in the original position, and these pore structures increase the porosity of super fine oil stone.

[0016] SiO2-B2O3-Al2O3-Sm2O3 glass powder can realize low temperature sintering of super fine oil stone, the addition of Sm2O3 can enter the glass network and increase the network porosity, reduce the high temperature viscosity of liquid phase, and make the liquid phase formation temperature drop, so as to accelerate the interface diffusion of glass phase and ceramic particles, promote low temperature densification, and improve the mechanical strength of super fine oil stone.

[0017] The super fine oil stone of the present application has excellent performance, uniform internal pore distribution, maintains the use performance while still maintaining high hardness, and can realize the unification of super long service life and excellent super fine polishing finishing effect. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The surface morphology of the raceway of the ring before superfinishing; Figure 2 The surface morphology of the raceway of the ring after superfinishing. DETAILED DESCRIPTION

[0019] Unless specific conditions are specified in the examples, conventional conditions or manufacturer's recommended conditions are used.The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be purchased on the market.The technologies not mentioned in the present application refer to the prior art, unless otherwise specified, the following examples and comparative examples are parallel tests, and the same processing steps and parameters are used.

[0020] Example 1: A method for preparing a super fine oil stone: Diatomaceous earth with an average particle size of 5 μm was placed in a muffle furnace and calcined at 450 °C for 4 h. After cooling to room temperature, 100 g of the calcined diatomaceous earth was added to 500 ml of a 1:1 mixture of anhydrous ethanol and water. Dilute acetic acid solution was added dropwise to adjust the pH to 4. The mixture was stirred in a water bath at 70 °C for 30 min. Then, 10 g of silane coupling agent KH-570 was added dropwise. The mixture was stirred and reacted for another 2 h. After filtration and drying, the modified diatomaceous earth was obtained. 12g of modified diatomaceous earth was added to 800ml of water and ultrasonically dispersed for 30min. Then, 1g of monomer N-isopropylacrylamide, 10mg of free radical initiator KPS and 5mg of accelerator TEMED were added under stirring. After stirring for 5h, the precipitate was filtered out, rinsed with cold water and dispersed in 800ml of 5wt% polyethylene glycol aqueous solution. Then, 100g of β-SiC with an average particle size of 5μm and 8g of glass powder were added. The mixture was heated to 50℃ and stirred for 30min, then filtered. The resulting solid was pressed in a mold at 25MPa for 1min and dried in an oven at 50℃ for 12h. Finally, it was sintered in a muffle furnace at 850℃ for 2h at a rate of 5℃ / min.

[0021] The glass powder is SiO2-B2O3-Al2O3-Sm2O3 glass powder, and the preparation method is as follows: SiO2, H3BO3, Al2O3, and Sm2O3 in a mass ratio of 25:55:15:5 were thoroughly mixed and ground. The mixture was first heated to 500℃ and held for 3 hours, then heated to 950℃ and held for 2 hours, and finally heated to 1250℃ and held for 1 hour. The resulting molten glass was then immersed in deionized water for water quenching. The water-quenched glass was then ground into powder with an average particle size of 2 μm and finally dried.

[0022] Example 2: A method for preparing super-essential oilstone: Diatomaceous earth with an average particle size of 5 μm was placed in a muffle furnace and calcined at 500 °C for 3 h. After cooling to room temperature, 100 g of the calcined diatomaceous earth was added to 500 ml of a 1:1 mixture of anhydrous ethanol and water. The pH was adjusted to 4 by adding dilute acetic acid solution dropwise. The mixture was stirred in a water bath at 70 °C for 30 min. Then, 10 g of silane coupling agent KH-570 was added dropwise. The mixture was stirred and reacted for another 2 h before being filtered and dried to obtain modified diatomaceous earth. Add 15g of modified diatomaceous earth to 800ml of water, and disperse by ultrasonic vibration for 30min. Then, add 1g of monomer N-isopropylacrylamide, 10mg of free radical initiator KPS and 5mg of accelerator TEMED under stirring. After stirring for 5h, filter out the precipitate, rinse with cold water and disperse in 800ml of 5wt% polyethylene glycol aqueous solution. Then, add 100g of β-SiC with an average particle size of 5μm and 5g of glass powder. Heat to 60℃ and stir for 10min, then filter. Press the resulting solid in a mold at 25MPa for 1min and dry in an oven at 40℃ for 12h. Finally, sinter in a muffle furnace at 900℃ for 2h at a rate of 5℃ / min.

[0023] The glass powder is SiO2-B2O3-Al2O3-Sm2O3 glass powder, and the preparation method is the same as in Example 1.

[0024] Example 3: A method for preparing super-essential oilstone: Diatomaceous earth with an average particle size of 5 μm was placed in a muffle furnace and calcined at 400℃ for 5 h. After cooling to room temperature, 100 g of the calcined earth was added to 500 ml of a 1:1 mixture of anhydrous ethanol and water. Dilute acetic acid solution was added dropwise to adjust the pH to 4. The mixture was stirred in a water bath at 70℃ for 30 min. Then, 10 g of silane coupling agent KH-570 was added dropwise. The mixture was stirred and reacted for another 2 h. After filtration and drying, the modified diatomaceous earth was obtained. 10g of modified diatomaceous earth was added to 800ml of water and ultrasonically dispersed for 30min. Then, 1g of monomer N-isopropylacrylamide, 10mg of free radical initiator KPS and 5mg of accelerator TEMED were added under stirring. After stirring for 5h, the precipitate was filtered out, rinsed with cold water and dispersed in 800ml of 5wt% polyethylene glycol aqueous solution. Then, 100g of β-SiC with an average particle size of 5μm and 10g of glass powder were added. The mixture was heated to 40℃ and stirred for 60min, then filtered. The resulting solid was pressed in a mold at 25MPa for 1min and dried in an oven at 60℃ for 12h. Finally, it was sintered in a muffle furnace at 800℃ for 2h at a rate of 5℃ / min.

[0025] The glass powder is SiO2-B2O3-Al2O3-Sm2O3 glass powder, and the preparation method is the same as in Example 1.

[0026] Comparative Example 1: The example is basically the same as Example 1, except that poly-N-isopropylacrylamide is not introduced, that is, calcined diatomaceous earth is used alone as a pore-forming agent. A method for preparing super-essential oilstone: Diatomaceous earth with an average particle size of 5 μm was placed in a muffle furnace and calcined at 450 °C for 4 h. After cooling to room temperature, it was dispersed in 800 ml of 5 wt% polyethylene glycol aqueous solution. Then, 100 g of β-SiC with an average particle size of 5 μm and 8 g of glass powder were added. The mixture was heated to 50 °C and stirred for 30 min, then filtered. The resulting solid was pressed in a mold at 25 MPa for 1 min and dried in an oven at 50 °C for 12 h. Finally, it was sintered in a muffle furnace at 850 °C for 2 h at a rate of 5 °C / min.

[0027] Comparative Example 2: The method is basically the same as in Example 1, except that the glass powder is SiO2-B2O3-Al2O3 glass powder, and the preparation method is as follows: SiO2, H3BO3, and Al2O3 in a mass ratio of 25:55:15 were thoroughly mixed and ground. The mixture was first heated to 500℃ and held for 3 hours, then heated to 950℃ and held for 2 hours, and finally heated to 1250℃ and held for 1 hour. The resulting molten glass was then immersed in deionized water for water quenching. The quenched glass was then ground into powder with an average particle size of 2 μm and finally dried.

[0028] Comparative Example 3: The method is basically the same as in Example 1, except that refined naphthalene is used instead of modified diatomaceous earth as the pore-forming agent, and the amount of pore-forming agent and the preparation method are also adjusted accordingly. A method for preparing super-essential oilstone: 100g of β-SiC with an average particle size of 5μm, 8g of glass powder and 10g of refined naphthalene were mixed evenly, and then 10g of sugar water with a mass concentration of 25% was added to obtain a wet material. The sugar water was made by dissolving edible white sugar in water. The wet material was pressed in a mold at 25MPa for 1min to form a shape and dried in an oven at 50℃ for 12h. Finally, it was sintered in a muffle furnace at a rate of 5℃ / min to 850℃ for 2h.

[0029] Comparative Example 4: The method is basically the same as in Example 1, except that dimethyl terephthalate is used instead of modified diatomaceous earth as the pore-forming agent, and the amount of pore-forming agent and the preparation method are also adjusted accordingly. A method for preparing super-essential oilstone: 100g of β-SiC with an average particle size of 5μm, 8g of glass powder and 10g of dimethyl terephthalate were mixed evenly, and then 10g of sugar syrup with a mass concentration of 25% was added to obtain a wet material. The sugar syrup was made by dissolving edible white sugar in water. The wet material was pressed in a mold at 25MPa for 1min to form a shape and dried in an oven at 50℃ for 12h. Finally, it was sintered in a muffle furnace at a rate of 5℃ / min to 850℃ for 2h.

[0030] Performance testing: ① The super oilstones prepared in Examples 1-3 and Comparative Examples 1-4 of the present invention were used as samples for performance testing.

[0031] The porosity and density of the samples were determined using the methods described in GB / T 1966-2024, "Determination of Apparent Porosity and Bulk Density of Porous Ceramics". The flexural strength was determined using the three-point bending method on a computer-controlled electronic universal testing machine. The sample dimensions were 80 mm × 12 mm × 8 mm. The Rockwell hardness of the samples was determined using a Rockwell hardness tester.

[0032] The test results are shown in Table 1 below: Table 1: As shown in Table 1 above, the super-fine oilstone of the present invention has a high porosity and maintains high hardness while maintaining its performance, thus achieving a balance between ultra-long lifespan and excellent ultra-fine finishing effect.

[0033] ② The ring was ultra-finished using the ultra-refined oilstone prepared in Example 1. The surface morphology of the ring groove was observed using a scanning electron microscope. The surface morphology of the ring groove before ultra-finishing is as follows: Figure 1 As shown in the figure, the surface quality of the channel is poor and does not meet the technical requirements of precision bearings. Ultra-precision machining of the channel is required to improve the surface quality of the channel.

[0034] The surface morphology of the raceway groove after ultra-precision machining is as follows Figure 2 As shown, after oilstone superfinishing, a large number of brittle fracture surfaces and plastic protrusions are removed, resulting in a smooth and flat surface. However, a small number of deep grooves remain. These grooves can store lubricating oil during bearing operation, which helps reduce internal frictional losses. The surface roughness of the grooves should not be too low; excessively low surface roughness will cause the rolling elements inside the bearing to not roll purely, resulting in relative sliding and affecting the bearing's service performance and lifespan. After superfinishing, the surface is relatively smooth, and the surface quality is significantly improved.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a super-essential oilstone, characterized in that, Specifically as follows: The calcined and KH-570 modified diatomaceous earth is dispersed in water, and the monomer N-isopropylacrylamide, free radical initiator and accelerator TEMED are added. After stirring at room temperature for 1-10 hours, the precipitate is filtered out, washed with cold water and dispersed in polyethylene glycol aqueous solution. Then, abrasive and glass powder are added, the temperature is raised to 40-60℃ and stirred for 10-60 minutes and filtered. The resulting solid is pressed in a mold, dried and finally sintered.

2. The method for preparing the super oilstone as described in claim 1, characterized in that, The calcination temperature of diatomaceous earth is 400-500℃.

3. The method for preparing the super oilstone as described in claim 1, characterized in that, The abrasive is silicon carbide.

4. The method for preparing the super oilstone as described in claim 1, characterized in that, The glass powder is SiO2-B2O3-Al2O3-Sm2O3 glass powder.

5. The method for preparing the super oilstone as described in claim 4, characterized in that, The preparation method of the SiO2-B2O3-Al2O3-Sm2O3 glass powder is as follows: After thoroughly mixing and grinding SiO2, H3BO3, Al2O3, and Sm2O3, the temperature is first raised to 400-600℃ and held for 1-5 hours, then raised to 800-1000℃ and held for 1-5 hours, and finally raised to 1200-1300℃ and held for 1-5 hours. The resulting molten glass is then immersed in deionized water for water quenching. The water-quenched glass is then ground into powder and dried.

6. The method for preparing the super oilstone as described in claim 5, characterized in that, The mass ratio of SiO2, H3BO3, Al2O3, and Sm2O3 is 20-25:50-60:10-15:1-5.

7. The method for preparing the super oilstone as described in claim 1, characterized in that, The mass ratio of the abrasive, glass powder and diatomaceous earth is 1:0.05-0.1:0.1-0.

15.

8. The method for preparing the super oilstone as described in claim 1, characterized in that, The pressure during pressing is 10-50 MPa.

9. The method for preparing the super oilstone as described in claim 1, characterized in that, The sintering temperature is 800-900℃.

10. A super essential oil stone, characterized in that, It is prepared by the method of any one of claims 1-9.

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