WO2023071897A1 - High-precision silicon nitride ceramic microsphere, and preparation method therefor and use thereof - Google Patents

High-precision silicon nitride ceramic microsphere, and preparation method therefor and use thereof Download PDF

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WO2023071897A1
WO2023071897A1 PCT/CN2022/126295 CN2022126295W WO2023071897A1 WO 2023071897 A1 WO2023071897 A1 WO 2023071897A1 CN 2022126295 W CN2022126295 W CN 2022126295W WO 2023071897 A1 WO2023071897 A1 WO 2023071897A1
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silicon nitride
nitride ceramic
preparation
wall
green body
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PCT/CN2022/126295
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French (fr)
Chinese (zh)
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张伟儒
公平
徐金梦
王文雪
孙峰
董廷霞
高翔
宋健
吕沛远
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中材高新氮化物陶瓷有限公司
中国航发哈尔滨轴承有限公司
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Priority to JP2023553433A priority Critical patent/JP2024512903A/en
Publication of WO2023071897A1 publication Critical patent/WO2023071897A1/en

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    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/584—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride
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    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C04B35/645—Pressure sintering
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
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    • F16C33/32—Balls
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    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance

Definitions

  • the invention relates to the technical field of ceramic ball preparation, in particular to a high-precision silicon nitride ceramic microsphere and its preparation method and application.
  • the high-speed dental drill ball bearing is a thin-walled ultra-light series precision miniature ball bearing. It has a high speed, requires fast start-up, low noise, can withstand certain axial and radial loads, and has good corrosion resistance and wear resistance. Performance, and requires long-term work in a wet mouth without rust, and the clinical life of it should reach six months under correct use conditions.
  • High-speed dental drill bearings were mainly imported from abroad in the past. Although there are a few domestic bearing companies producing them, their quality, specifications and quantity cannot meet the needs of the market. Therefore, the research and development of high-speed dental drill bearings is of great significance.
  • Si 3 N 4 ceramic balls have low density and light weight, which not only significantly reduces the centrifugal force of the ball, but also significantly reduces the gyroscopic moment of the ball, thereby reducing the preload of the bearing and reducing the contact load inside the bearing, so that the frictional moment and The frictional temperature rise is significantly reduced.
  • silicon nitride ceramic balls have the characteristics of high hardness, corrosion resistance, friction and wear, and small thermal expansion coefficient. They have low heat absorption, low cooling requirements, and can operate in environments with poor lubrication conditions. At the same time, ceramic balls are difficult to adhere to the steel surface and wear. At high speed and light load, silicon nitride ceramic ball bearings have a longer life than all-steel bearings. Therefore, silicon nitride ceramic balls are very suitable as the rolling body material of high-speed dental drill bearings.
  • the surface roughness of the rolling elements of the bearing is the main cause of the vibration of the bearing, which will cause noise in the bearing.
  • the vibration of a single ceramic sphere is mainly caused by the surface quality defect of the sphere and the geometric shape error of the sphere.
  • the surface quality defects of silicon nitride ceramic microspheres for dental drills are mainly pores, pits, abnormally large grains and snowflakes, which seriously affect the surface roughness of ceramic balls and reduce the service life.
  • the purpose of the present invention is to provide a high-precision silicon nitride ceramic microsphere and its preparation method and application, which solves the defects of silicon nitride ceramic microspheres such as pores, abnormally large grains, surface pits and snowflakes, and realizes nitrogen High-precision preparation of silica ceramic microspheres.
  • the invention provides a method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps:
  • the larger The diameter of the silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body;
  • the crucible is a crucible with multi-layer side walls, and the multi-layer side walls are sequentially It includes graphite outer wall, middle wall and inner wall; the extension direction of the middle wall and the inner wall is consistent with the extension direction of the crucible outer wall, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than that of the crucible The diameter of the large-size silicon nitride ceramic green ball;
  • the diameter of the larger-sized silicon nitride ceramic green ball is 20-35 mm; the diameter of the pressed silicon nitride ceramic microsphere green body is 0.8-4 mm.
  • the mass ratio of the pressed silicon nitride ceramic microsphere green body to the larger-sized silicon nitride ceramic green body ball is 1: (1-3).
  • the temperature of the atmosphere pressure sintering is 1700-1800° C.
  • the holding time is 1-3 hours
  • the atmosphere pressure sintering is carried out under the protection of nitrogen.
  • the temperature of the hot isostatic pressing sintering is 1800-1850° C.
  • the holding time is 0.5-1 h
  • the hot isostatic pressing sintering is carried out under the protection of nitrogen
  • the pressure of the nitrogen gas during the hot isostatic pressing sintering is 200 ⁇ 210MPa.
  • the mass of the sintering aid is 3-5% of the total mass of the silicon nitride powder and the sintering aid.
  • the sintering aid includes one or more of alumina, lanthanum oxide, neodymium oxide, ytterbium oxide, erbium oxide and samarium oxide.
  • the loading into the crucible is a cavity formed by filling the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body balls into the interlayer and inner wall of the crucible with multi-layer side walls middle.
  • the present invention provides high-precision silicon nitride ceramic microspheres prepared by the preparation method described in the above proposal.
  • the surface roughness Ra of the high-precision silicon nitride ceramic microspheres satisfies: 0.006 ⁇ m ⁇ Ra ⁇ 0.008 ⁇ m, and the ball diameter varies
  • the quantity VDw satisfies: 0.03 ⁇ m ⁇ VDw ⁇ 0.08 ⁇ m
  • the spherical error ⁇ Sph satisfies: 0.03 ⁇ m ⁇ Sph ⁇ 0.08 ⁇ m.
  • the present invention provides the application of the high-precision silicon nitride ceramic microspheres described in the above scheme in dental drill bearings.
  • the invention provides a method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps: performing ball milling and mixing of silicon nitride powder, sintering aid and dispersion liquid to obtain a mixed material liquid; Spray granulation to obtain granulated powder; press the granulated powder to obtain a pressed silicon nitride ceramic microsphere green body; Put the green ball into the crucible and carry out the atmosphere pressure sintering and hot isostatic pressing sintering successively to obtain the silicon nitride green green ball; 5 to 50 times the diameter; the crucible is a crucible with a multi-layer side wall, and the multi-layer side wall includes a graphite outer wall, an intermediate wall and an inner wall from outside to inside; The extension direction of the same, the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than the diameter of the silicon nitride ceramic green ball; the silicon nit
  • the pressed silicon nitride ceramic microsphere green body and the larger-sized silicon nitride ceramic green body ball are sintered together, because the diameter of the larger-sized silicon nitride ceramic green body ball is larger than the pressed silicon nitride ceramic microsphere green body diameter, when loaded into the crucible, the pressed silicon nitride ceramic microsphere green body will be filled into the gap of the large-size silicon nitride ceramic green body ball, which is beneficial to the pressed silicon nitride ceramic microsphere green body to be heated evenly during the sintering process
  • the present invention adopts the multilayer side wall crucible to carry out sintering, and the material of the middle wall and the interior is silicon nitride, and silicon nitride can absorb part of heat, prevents the compacted silicon nitride ceramic microsphere blank from being overheated locally and causes The crystal grains grow abnormally, and defects such as white pits and snowflakes appear on the surface.
  • the present invention can further improve the density of silicon nitride ceramic microspheres, reduce pores and abnormally large Grain defects, thereby improving the mechanical properties, stability and surface quality of Si 3 N 4 ceramic balls.
  • the present invention controls the quality of the sintering aid to be 3 to 5% of the total mass of the silicon nitride powder and the sintering aid.
  • the nitrogen oxide liquid phase formed by the reaction of the sintering aid and the particle surface material is less, and after sintering There are few glass phases left between the grain boundaries, and the ceramic balls have high purity, which is beneficial to improving the mechanical properties of the silicon nitride ceramic microspheres.
  • the Vickers hardness HV10 of the high-precision silicon nitride ceramic microspheres prepared by the present invention can reach up to 1524kg/mm 2
  • the fracture toughness can reach up to 8.6MPa ⁇ m 1/2
  • the surface roughness is 0.006 ⁇ m ⁇ Ra ⁇ 0.008 ⁇ m
  • ball diameter variation 0.03 ⁇ m ⁇ V Dw ⁇ 0.08 ⁇ m
  • spherical error 0.03 ⁇ m ⁇ S ph ⁇ 0.08 ⁇ m
  • all performance indicators are in line with GB/T308.2-2010/ISO3290-2: 2008 "Rolling Bearing Ball Part 2: G3 level standard requirements for silicon nitride ceramic microbeads.
  • Fig. 1 is the structural representation of crucible used for sintering of the present invention
  • Fig. 2 is wherein a photo of silicon nitride microspheres prepared in comparative example 1;
  • the invention provides a method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps:
  • the larger The diameter of the silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body;
  • the crucible is a crucible with multi-layer side walls, and the multi-layer side walls are sequentially It includes graphite outer wall, middle wall and inner wall; the extension direction of the middle wall and the inner wall is consistent with the extension direction of the crucible outer wall, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than that of the crucible The diameter of the large-size silicon nitride ceramic green ball;
  • the raw materials used are commercially available products well known in the art.
  • the silicon nitride powder, the sintering aid and the dispersion liquid are ball-milled and mixed to obtain the mixed material liquid.
  • the mass of the sintering aid is preferably 3-5% of the total mass of the silicon nitride powder and the sintering aid;
  • the sintering aid preferably includes alumina, lanthanum oxide, neodymium oxide, ytterbium oxide, oxide One or more of erbium and samarium oxide, more preferably 3% alumina + 2% lanthanum oxide, 2% alumina + 1% lutetium oxide, or 2% alumina + 2% erbium oxide.
  • the percentages in this paragraph refer to the total mass of silicon nitride powder and sintering aid.
  • the dispersion liquid is preferably absolute ethanol; the ratio of the mass of the dispersion liquid to the total mass of the silicon nitride powder and the sintering aid is preferably (3-4):1.
  • the grinding balls used in the ball mill mixing are preferably silicon nitride grinding balls, and the ratio of the mass of the silicon nitride grinding balls to the total mass of silicon nitride powder and sintering aid is preferably (1.5-3) :1, more preferably 2:1.
  • the time for ball milling and mixing is preferably 18-24 hours.
  • the mixing by ball milling is preferably by drum milling. In the present invention, there is no special requirement on the rotating speed of the ball milling, and the rotating speed well known in the art can be used.
  • the present invention sprays and granulates the mixed material liquid to obtain granulated powder.
  • the spray granulation is preferably in the form of pressure spray granulation.
  • the present invention preferably carries out spray granulation in a spray granulation tower.
  • the present invention has no special requirements on the conditions of the spray granulation, and the spray granulation conditions well known in the art can be used.
  • the inlet temperature of the spray granulation tower used is 190° C.
  • the hole diameter of the nozzle is 0.9 mm.
  • the particle size of the granulated powder is preferably 50-100 ⁇ m.
  • the invention utilizes spray granulation to improve the fluidity of the granulated powder, which is beneficial to subsequent compression molding.
  • the present invention compresses the granulated powder to obtain a pressed silicon nitride ceramic microsphere compact.
  • the compression molding is preferably performed using the ceramic microbead molding device described in Chinese patent CN202023003181.3.
  • the diameter of the pressed silicon nitride ceramic microsphere green body is preferably 0.8-4mm.
  • the present invention puts the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body balls into a crucible to carry out atmosphere pressure sintering and hot isostatic sintering successively. Press and sinter to obtain silicon nitride green balls.
  • the present invention has no special requirements on the chemical composition of the larger-sized silicon nitride ceramic green balls, and any silicon nitride ceramic green balls known in the art can be used.
  • the relatively large-sized silicon nitride nitride ceramic green ball is preferably formed by dry pressing using a rotary press by means of an upper die and a lower die.
  • the diameter of the larger-sized silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body. More preferably, the larger-sized silicon nitride The diameter of the ceramic green ball is 20-35 mm, and the diameter of the pressed silicon nitride ceramic microsphere green body is 0.8-4 mm. In the present invention, the mass ratio of the pressed silicon nitride ceramic microsphere green body to the larger-sized silicon nitride ceramic green body ball is preferably 1: (1-3), more preferably 1: (1.5-2.5) .
  • the present invention carries out atmosphere pressure sintering and hot isostatic pressing sintering successively together with the larger-sized silicon nitride ceramic green body pressed silicon nitride ceramic microsphere green body, because the diameter of larger-sized silicon nitride ceramic green body ball is larger than The diameter of the pressed silicon nitride ceramic microsphere green body, when the ceramic ball is loaded into the crucible, the pressed silicon nitride ceramic microsphere green body will be filled into the gap of the larger size silicon nitride ceramic green body ball, which is beneficial to the pressing and nitriding
  • the silicon ceramic microsphere green body is evenly heated during the sintering process to prevent abnormal grain growth, white pits, snowflakes and other defects on the surface caused by excessive local heating.
  • the crucible is a crucible with multilayer side walls.
  • the multilayer side walls include graphite outer wall, middle wall and inner wall from outside to inside; the extension of the middle wall and inner wall The direction is consistent with the extension direction of the outer wall of the crucible, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than the diameter of the silicon nitride ceramic green ball.
  • the multi-layer side wall crucible has an integrated structure, and the graphite outer wall, middle wall and inner wall share the same crucible bottom.
  • the thickness of the inner wall is preferably 2 to 4 mm, and the inner diameter of the concentric circle formed by the inner wall is preferably 90 to 100 mm; the thickness of the intermediate wall is preferably 3 to 5 mm, and the inner diameter of the concentric circle formed by the intermediate wall is preferably 180-200 mm; the thickness of the graphite outer wall is preferably 8-10 mm, and the inner diameter of the formed concentric circles is preferably 300-320 mm.
  • the bottom thickness of the crucible is preferably 6-8mm.
  • the height of each side wall of the crucible is preferably the same, and the height is preferably 15-17 mm.
  • the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body balls are preferably packed into the cavity formed by the interlayer and inner wall of the multilayer sidewall crucible.
  • the present invention uses a crucible with multi-layer side walls to carry out atmosphere pressure sintering and hot isostatic pressing sintering sequentially, and the material of the middle wall and the inside is silicon nitride, which can absorb part of the heat and prevent the pressing of silicon nitride ceramic microspheres. Partial heating of the green body is too high, resulting in abnormal grain growth, white pits, snowflakes and other defects on the surface.
  • the temperature of the atmosphere pressure sintering is preferably 1700-1800°C, more preferably 1720-1780°C; the holding time is preferably 1-3h, more preferably 2h; the atmosphere pressure sintering is preferably under the protection of nitrogen conduct.
  • the temperature is preferably raised from room temperature to the temperature of the atmosphere pressure sintering, and the heating rate is preferably 5-20° C./min.
  • the invention utilizes atmosphere pressure sintering to obtain Si 3 N 4 ceramics without open pores.
  • the present invention is preferably cooled to room temperature, and then hot isostatic pressing sintering is performed.
  • the temperature of the hot isostatic pressing sintering is preferably 1800-1850°C
  • the holding time is preferably 0.5-1h
  • the hot isostatic pressing sintering is preferably carried out under nitrogen protection
  • the hot isostatic pressing sintering The pressure of the nitrogen gas is preferably 200 to 210 MPa.
  • the temperature increase rate to the temperature of the hot isostatic pressing sintering is preferably 5-20° C./min.
  • the present invention performs hot isostatic pressing sintering after atmospheric pressure sintering, which can further increase the density of silicon nitride ceramic microspheres and reduce abnormally large grain defects, thereby improving the density, mechanical properties, and stability of Si 3 N 4 ceramic balls. and surface quality.
  • both the atmosphere pressure sintering and the hot isostatic pressing sintering adopt the multi-layer side wall crucible of the present invention.
  • the present invention removes larger-sized silicon nitride ceramic green balls to obtain silicon nitride green balls.
  • the present invention grinds the silicon nitride green balls to obtain high-precision silicon nitride ceramic microspheres.
  • the grinding process preferably includes rough grinding, fine grinding, fine grinding, fine grinding and superfinishing in sequence.
  • the grinding process is preferably performed using the silicon nitride ceramic microbead batch processing device disclosed in Chinese patent CN 202021836565.0.
  • the upper and lower grinding plates of the grinding device are all cast iron plates, and the size is preferably ⁇ 660mm ⁇ 420mm.
  • the pressure applied between the upper and lower grinding plates is preferably (0.8 ⁇ 1) ⁇ 10KN
  • the spindle speed is preferably 100 ⁇ 120r/min
  • the machining allowance of the rough grinding is preferably 250 ⁇ 350 ⁇ m.
  • the pressure applied between the upper and lower grinding plates is preferably (0.6 ⁇ 0.9) ⁇ 10KN
  • the spindle speed is preferably 80 ⁇ 100r/min
  • the machining allowance of the fine grinding is preferably ⁇ 150 ⁇ m and ⁇ 250 ⁇ m.
  • the pressure applied between the upper and lower grinding plates is preferably (0.4 ⁇ 0.7) ⁇ 10KN
  • the spindle speed is preferably 70 ⁇ 80r/min
  • the machining allowance of the fine grinding is preferably ⁇ 50 ⁇ m and ⁇ 100 ⁇ m.
  • the pressure applied between the upper and lower grinding plates is preferably (0.3-0.6) ⁇ 10KN
  • the spindle speed is preferably 60-70r/min
  • the machining allowance of the lapping is preferably ⁇ 30 ⁇ m and ⁇ 50 ⁇ m.
  • the pressure applied between the upper and lower grinding plates is preferably (0.1 ⁇ 0.3) ⁇ 10KN
  • the spindle speed is preferably 50 ⁇ 60r/min
  • the machining allowance of the superfinishing If it is 0, the target size is reached.
  • the present invention provides high-precision silicon nitride ceramic microspheres prepared by the preparation method described in the above proposal.
  • the surface roughness Ra of the high-precision silicon nitride ceramic microspheres satisfies: 0.006 ⁇ m ⁇ Ra ⁇ 0.008 ⁇ m, and the ball diameter varies
  • the quantity VDw satisfies: 0.03 ⁇ m ⁇ VDw ⁇ 0.08 ⁇ m
  • the spherical error ⁇ Sph satisfies: 0.03 ⁇ m ⁇ Sph ⁇ 0.08 ⁇ m.
  • the Vickers hardness HV10 of the high-precision silicon nitride ceramic microspheres can reach up to 1480kg/mm 2
  • the fracture toughness can reach up to 8MPa ⁇ m 1/2
  • all performance indicators conform to GB/T308.2-2010 /ISO3290-2:2008 "Rolling Bearing Balls Part 2: Silicon Nitride Ceramic Microballs" standard requirements of the G3 level standard requirements.
  • the size of the high-precision silicon nitride ceramic microspheres is preferably 0.4-1 mm.
  • the present invention provides the application of the high-precision silicon nitride ceramic microspheres described in the above scheme in dental drill bearings.
  • the thickness of the inner wall is 3mm, and the inner diameter of the concentric circle formed by the inner wall is 100mm; the thickness of the middle wall is 4mm, and the inner diameter of the concentric circle formed by the middle wall is 180mm; the thickness of the graphite outer wall is 10mm, and the inner diameter of the formed concentric circle is 320mm.
  • the bottom thickness of the multilayer sidewall crucible is 6mm, and the height of each sidewall of the multilayer sidewall crucible is the same, which is 15mm.
  • the silicon nitride rough ball is subjected to rough grinding, fine grinding, fine grinding, fine grinding and super-finishing processing, and the upper and lower grinding plates are made of cast iron with a specification of ⁇ 660mm ⁇ 420mm.
  • the pressure applied between the upper and lower grinding plates in the grinding process is 1 ⁇ 10KN, and the spindle speed is 110r/min; the pressure applied between the upper and lower grinding plates in the fine grinding process is 0.9 ⁇ 10KN, and the spindle speed is 90r/min;
  • the pressure applied between the upper and lower grinding plates is 0.7 ⁇ 10KN, the spindle speed is 80r/min; the pressure applied between the upper and lower grinding plates in the lapping process is 0.6 ⁇ 10KN, and the spindle speed is 70r/min;
  • the pressure applied between the upper and lower grinding plates in the process is 0.3 ⁇ 10KN, the spindle speed is 60r/min, and the finished product of ⁇ 1mm silicon nitride ceramic microspheres is obtained.
  • the aluminum oxide of 3wt% content, the lanthanum oxide of 2wt% content and the silicon nitride of 95wt% content are used as powder, and dehydrated alcohol (weight is 2 times of powder gross weight) is dispersion liquid, and powder , the dispersion liquid and silicon nitride grinding balls (weight is 2 times of the total weight of the powder) are put into the drum mill for ball milling and mixing, and the mixing time is 24h to obtain the mixed material liquid;
  • the upper and lower grinding plates are made of cast iron with a specification of ⁇ 660mm ⁇ 420mm.
  • the pressure applied between the upper and lower grinding plates in the grinding process is 0.8 ⁇ 10KN, and the spindle speed is 110r/min; the pressure applied between the upper and lower grinding plates in the fine grinding process is between 0.7 ⁇ 10KN, and the spindle speed is 90r/min;
  • the pressure applied between the upper and lower grinding plates in the grinding process is between 0.6 ⁇ 10KN, and the spindle speed is 70r/min;
  • the pressure applied between the upper and lower grinding plates in the finishing process is between 0.5 ⁇ 10KN, and the spindle speed is 60r/min ;
  • the pressure applied between the upper and lower grinding plates is between 0.2 ⁇ 10KN, the spindle speed is 60r/min, and the finished product of ⁇ 0.8mm silicon nitride ceramic microspheres
  • the aluminum oxide of 2wt% content, the lutetium oxide of 1wt% content and the silicon nitride powder of 97wt% content are used as powder, and dehydrated alcohol (weight is 2 times of powder gross weight) is dispersion liquid, powder Material, absolute ethanol and silicon nitride grinding balls (weight is 2 times of the total weight of the powder) were put into the drum mill for ball milling and mixing, and the mixing time was 24h to obtain the mixed material liquid;
  • the upper and lower grinding plates are made of cast iron with a specification of ⁇ 660mm ⁇ 420mm.
  • the pressure applied between the upper and lower grinding plates in the grinding process is 0.8 ⁇ 10KN, and the spindle speed is 100r/min; the pressure applied between the upper and lower grinding plates in the fine grinding process is 0.6 ⁇ 10KN, and the spindle speed is 80r/min;
  • the pressure applied between the upper and lower grinding plates is 0.4 ⁇ 10KN, and the spindle speed is 70r/min;
  • the pressure applied between the upper and lower grinding plates in the lapping process is 0.3 ⁇ 10KN, and the spindle speed is 60r/min;
  • the pressure applied between the lower grinding plates is 0.1 ⁇ 10KN, the spindle speed is 50r/min, and the finished product of ⁇ 0.4mm silicon nitride ceramic microspheres is obtained.
  • Example 1 The difference from Example 1 is only that a common single-layer crucible is used.
  • Example 1 The difference from Example 1 is only that silicon nitride ceramic green balls with a diameter of 20 mm are not used during sintering.
  • Example 1 The difference from Example 1 is only that hot isostatic pressing sintering is omitted.
  • Example 1 The difference from Example 1 is only that the atmosphere pressure sintering is omitted.
  • Example 1 The finished products of Examples 1-3 and Comparative Examples 1-4 were subjected to mechanical performance test and precision test, wherein, the mechanical performance test refers to ASTM F2094-2018a, and the precision test refers to GB/T308.2-2010/ISO3290-2:2008 " Rolling Bearing Balls Part 2: Silicon Nitride Ceramic Microballs", the test results are shown in Table 1.
  • the density of the silicon nitride ceramic microspheres prepared in Comparative Example 1 reached 99.53%, the hardness only reached the ASTM F2094-2018a Class II material standard, the fracture toughness and three-point bending strength reached the Class I material standard, and the precision grade reached GB/T308.2 G10 grade standard, white spots and snowflake ratios are 32% and 18% respectively; the density of silicon nitride ceramic microspheres prepared in Comparative Example 2 reaches 99.41%, the hardness only reaches the ASTM F2094-2018a II material standard, and the fracture toughness and three The point bending strength reaches the material standard of Class I, the precision grade reaches the standard of GB/T308.2 G10, the proportion of white spots and snowflakes is 35% and 21% respectively; the density of silicon nitride ceramic microspheres prepared in Comparative Example 3 only reaches 95.11 %, the hardness is lower than the ASTM F2094-2018a grade III material standard, the fracture toughness reaches the II grade material standard, the three
  • the present invention solves the problem of silicon nitride ceramic microspheres by adopting a sintering method combining atmospheric pressure sintering and hot isostatic pressing sintering, adopting larger-sized silicon nitride ceramic green balls and adopting multilayer sidewall crucibles for sintering.
  • a sintering method combining atmospheric pressure sintering and hot isostatic pressing sintering, adopting larger-sized silicon nitride ceramic green balls and adopting multilayer sidewall crucibles for sintering.
  • defects such as pores, abnormally large grains, surface pits and snowflakes, and the high-precision preparation of silicon nitride ceramic microspheres is realized.
  • FIG. 2 is a photo of one of the silicon nitride microspheres prepared in Comparative Example 1. It can be seen from FIG. 2 that white pits appear on the surface of the silicon nitride microspheres.
  • FIG. 3 is a scanning electron microscope image of one of the silicon nitride microspheres prepared in Comparative Example 1. It can be seen that abnormally large grains appear.

Abstract

Provided in the present invention are a high-precision silicon nitride ceramic microsphere, and a preparation method therefor and the use thereof, belonging to the technical field of ceramic sphere preparation. According to the present invention, the defects of pores, abnormal large grains, surface pits, flakes, etc. of silicon nitride ceramic microspheres are overcome, and the high-precision preparation of a silicon nitride ceramic microsphere is realized. The results of embodiments show that the Vickers hardness HV10 of the high-precision silicon nitride ceramic microsphere prepared in the present invention reaches up to 1524 kg/mm2, the fracture toughness reaches up to 8.6 MPa·m1/2, the surface roughness Ra is greater than or equal to 0.006 μm and less than or equal to 0.008 μm, the sphere diameter variation VDw is greater than or equal to 0.03 μm and less than or equal to 0.08 μm, the sphericity error △Sph is greater than or equal to 0.03 μm and less than or equal to 0.08 μm, and all the performance indexes of the high-precision silicon nitride ceramic microsphere meet the G3-level standard requirements prescribed in Rolling Bearing Balls Part 2: Silicon Nitride Ceramic Microbeads GB/T308.2-2010/ISO3290-2:2008.

Description

一种高精度氮化硅陶瓷微球及其制备方法和应用A kind of high precision silicon nitride ceramic microsphere and its preparation method and application
本申请要求于2021年10月26日提交中国专利局、申请号为202111246756.0、发明名称为“一种高精度氮化硅陶瓷微球及其制备方法和应用”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application submitted to the China Patent Office on October 26, 2021, the application number is 202111246756.0, and the invention title is "a high-precision silicon nitride ceramic microsphere and its preparation method and application". The entire contents are incorporated by reference in this application.
技术领域technical field
本发明涉及陶瓷球制备技术领域，尤其涉及一种高精度氮化硅陶瓷微球及其制备方法和应用。The invention relates to the technical field of ceramic ball preparation, in particular to a high-precision silicon nitride ceramic microsphere and its preparation method and application.
背景技术Background technique
近年来随着人民生活水平和生活质量的提高，对牙病防治日益重视和普及。目前国内对牙医手机配套的高速牙钻轴承的需求不断增加。高速牙钻球轴承是一种薄壁超轻系列的精密微型球轴承，其转速较高，工作时要求启动快，低噪音，能承受一定的轴向和径向负荷，具有良好的耐腐蚀及耐磨性能，并要求长期在潮湿的口腔中工作而不锈蚀，在正确使用条件下临床寿命要达到六个月。高速牙钻轴承以前主要是从国外进口，现在国内虽有少数几家轴承企业生产，但其质量、规格和数量都满足不了市场的需求，所以对高速牙钻轴承的研发具有重要意义。Along with the raising of people's living standard and quality of life in recent years, dental disease prevention and treatment is paid more and more attention to and popularized day by day. At present, the domestic demand for high-speed dental drill bearings for dentist mobile phones continues to increase. The high-speed dental drill ball bearing is a thin-walled ultra-light series precision miniature ball bearing. It has a high speed, requires fast start-up, low noise, can withstand certain axial and radial loads, and has good corrosion resistance and wear resistance. Performance, and requires long-term work in a wet mouth without rust, and the clinical life of it should reach six months under correct use conditions. High-speed dental drill bearings were mainly imported from abroad in the past. Although there are a few domestic bearing companies producing them, their quality, specifications and quantity cannot meet the needs of the market. Therefore, the research and development of high-speed dental drill bearings is of great significance.
Si 3N 4陶瓷球密度低，质量轻，不仅显著降低球的离心力，而且显著降低球的陀螺力矩，从而降低轴承的预紧载荷和减小轴承内部的接触载荷，使轴承内部的摩擦力矩和摩擦温升显著降低。此外，氮化硅陶瓷球具有硬度高、耐腐蚀和摩擦磨损、热膨胀系数小等特点，其吸收热量低，冷却要求较低，能在润滑条件差的环境中运转。同时陶瓷球较难和钢表面出现黏附磨损，在高速轻载时，氮化硅陶瓷球轴承比全钢轴承寿命长。因此，氮化硅陶瓷球非常适合作为高速牙钻轴承滚动体的材料。 Si 3 N 4 ceramic balls have low density and light weight, which not only significantly reduces the centrifugal force of the ball, but also significantly reduces the gyroscopic moment of the ball, thereby reducing the preload of the bearing and reducing the contact load inside the bearing, so that the frictional moment and The frictional temperature rise is significantly reduced. In addition, silicon nitride ceramic balls have the characteristics of high hardness, corrosion resistance, friction and wear, and small thermal expansion coefficient. They have low heat absorption, low cooling requirements, and can operate in environments with poor lubrication conditions. At the same time, ceramic balls are difficult to adhere to the steel surface and wear. At high speed and light load, silicon nitride ceramic ball bearings have a longer life than all-steel bearings. Therefore, silicon nitride ceramic balls are very suitable as the rolling body material of high-speed dental drill bearings.
轴承在工作时，其振动会严重影响寿命，从而影响工作设备的稳定性、可靠性。相比于套圈和保持架，轴承滚动体的表面粗糙度是轴承振动的主要原因，会使轴承产生杂音。单粒陶瓷球体的振动主要由球体表面质量缺陷和球体的几何形状误差产生。目前，牙钻用氮化硅陶瓷微球表面质量缺陷主要为气孔、凹坑、异常大晶粒和雪花，严重影响陶瓷球表面粗糙度从 而降低使用寿命。When the bearing is working, its vibration will seriously affect the service life, thus affecting the stability and reliability of the working equipment. Compared with the rings and cages, the surface roughness of the rolling elements of the bearing is the main cause of the vibration of the bearing, which will cause noise in the bearing. The vibration of a single ceramic sphere is mainly caused by the surface quality defect of the sphere and the geometric shape error of the sphere. At present, the surface quality defects of silicon nitride ceramic microspheres for dental drills are mainly pores, pits, abnormally large grains and snowflakes, which seriously affect the surface roughness of ceramic balls and reduce the service life.
发明内容Contents of the invention
本发明的目的在于提供一种高精度氮化硅陶瓷微球及其制备方法和应用，解决了氮化硅陶瓷微球存在气孔、异常大晶粒、表面凹坑及雪花等缺陷，实现了氮化硅陶瓷微球的高精度制备。The purpose of the present invention is to provide a high-precision silicon nitride ceramic microsphere and its preparation method and application, which solves the defects of silicon nitride ceramic microspheres such as pores, abnormally large grains, surface pits and snowflakes, and realizes nitrogen High-precision preparation of silica ceramic microspheres.
为了实现上述发明目的，本发明提供以下技术方案：In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:
本发明提供了一种高精度氮化硅陶瓷微球的制备方法，包括以下步骤：The invention provides a method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps:
将氮化硅粉、烧结助剂和分散液进行球磨混合，得到混合料液；Ball milling and mixing the silicon nitride powder, sintering aid and dispersion liquid to obtain a mixed material liquid;
将所述混合料液进行喷雾造粒，得到造粒粉；Spraying and granulating the mixed material liquid to obtain granulated powder;
将所述造粒粉压制成型，得到压制氮化硅陶瓷微球素坯；Compressing the granulated powder to obtain a pressed silicon nitride ceramic microsphere green body;
将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入坩埚中依次进行气氛压力烧结和热等静压烧结，得到氮化硅毛坯球；所述较大尺寸氮化硅陶瓷素坯球的直径为压制氮化硅陶瓷微球素坯的直径的5～50倍；所述坩埚为多层侧壁的坩埚，所述多层侧壁由外到内依次包括石墨外壁、中间壁和内壁；所述中间壁和内壁的延伸方向与坩埚外壁的延伸方向一致，所述中间壁和内壁的材质为氮化硅；相邻层侧壁之间的间隙大于较大尺寸氮化硅陶瓷素坯球的直径；Put the pressed silicon nitride ceramic microsphere green body and the silicon nitride ceramic green body ball with larger size into the crucible to carry out atmosphere pressure sintering and hot isostatic pressing sintering sequentially to obtain the silicon nitride green body ball; the larger The diameter of the silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body; the crucible is a crucible with multi-layer side walls, and the multi-layer side walls are sequentially It includes graphite outer wall, middle wall and inner wall; the extension direction of the middle wall and the inner wall is consistent with the extension direction of the crucible outer wall, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than that of the crucible The diameter of the large-size silicon nitride ceramic green ball;
将所述氮化硅毛坯球进行磨削加工，得到高精度氮化硅陶瓷微球。Grinding the silicon nitride rough balls to obtain high-precision silicon nitride ceramic microspheres.
优选的，所述较大尺寸氮化硅陶瓷素坯球的直径为20～35mm；所述压制氮化硅陶瓷微球素坯的直径为0.8～4mm。Preferably, the diameter of the larger-sized silicon nitride ceramic green ball is 20-35 mm; the diameter of the pressed silicon nitride ceramic microsphere green body is 0.8-4 mm.
优选的，所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球的质量比为1：(1～3)。Preferably, the mass ratio of the pressed silicon nitride ceramic microsphere green body to the larger-sized silicon nitride ceramic green body ball is 1: (1-3).
优选的，所述气氛压力烧结的温度为1700～1800℃，保温时间为1～3h，所述气氛压力烧结在氮气保护下进行。Preferably, the temperature of the atmosphere pressure sintering is 1700-1800° C., the holding time is 1-3 hours, and the atmosphere pressure sintering is carried out under the protection of nitrogen.
优选的，所述热等静压烧结的温度为1800～1850℃，保温时间为0.5～1h，所述热等静压烧结在氮气保护下进行，所述热等静压烧结时氮气的压力为200～210MPa。Preferably, the temperature of the hot isostatic pressing sintering is 1800-1850° C., the holding time is 0.5-1 h, the hot isostatic pressing sintering is carried out under the protection of nitrogen, and the pressure of the nitrogen gas during the hot isostatic pressing sintering is 200～210MPa.
优选的，所述烧结助剂的质量为氮化硅粉和烧结助剂总质量的3～5％。Preferably, the mass of the sintering aid is 3-5% of the total mass of the silicon nitride powder and the sintering aid.
优选的，所述烧结助剂包括氧化铝、氧化镧、氧化钕、氧化镱、氧化铒和氧化钐中的一种或多种。Preferably, the sintering aid includes one or more of alumina, lanthanum oxide, neodymium oxide, ytterbium oxide, erbium oxide and samarium oxide.
优选的，所述装入坩埚中为将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入多层侧壁的坩埚的层间和内壁形成的腔体中。Preferably, the loading into the crucible is a cavity formed by filling the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body balls into the interlayer and inner wall of the crucible with multi-layer side walls middle.
本发明提供了上述方案所述制备方法制备得到的高精度氮化硅陶瓷微球，所述高精度氮化硅陶瓷微球的表面粗糙度Ra满足：0.006μm≤Ra≤0.008μm，球直径变动量VDw满足：0.03μm≤VDw≤0.08μm，球形误差△Sph满足：0.03μm≤△Sph≤0.08μm。The present invention provides high-precision silicon nitride ceramic microspheres prepared by the preparation method described in the above proposal. The surface roughness Ra of the high-precision silicon nitride ceramic microspheres satisfies: 0.006μm≤Ra≤0.008μm, and the ball diameter varies The quantity VDw satisfies: 0.03μm≤VDw≤0.08μm, and the spherical error △Sph satisfies: 0.03μm≤△Sph≤0.08μm.
本发明提供了上述方案所述高精度氮化硅陶瓷微球在牙钻轴承中的应用。The present invention provides the application of the high-precision silicon nitride ceramic microspheres described in the above scheme in dental drill bearings.
本发明提供了一种高精度氮化硅陶瓷微球的制备方法，包括以下步骤：将氮化硅粉、烧结助剂和分散液进行球磨混合，得到混合料液；将所述混合料液进行喷雾造粒，得到造粒粉；将所述造粒粉压制成型，得到压制氮化硅陶瓷微球素坯；将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入坩埚中依次进行气氛压力烧结和热等静压烧结，得到氮化硅毛坯球；所述较大尺寸氮化硅陶瓷素坯球的直径为压制氮化硅陶瓷微球素坯的直径的5～50倍；所述坩埚为多层侧壁的坩埚，所述多层侧壁由外到内依次包括石墨外壁、中间壁和内壁；所述中间壁和内壁的延伸方向与坩埚外壁的延伸方向一致，所述中间壁和内壁的材质为氮化硅；相邻层侧壁之间的间隙大于较大尺寸氮化硅陶瓷素坯球的直径；将所述氮化硅毛坯球进行磨削加工，得到高精度氮化硅陶瓷微球。The invention provides a method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps: performing ball milling and mixing of silicon nitride powder, sintering aid and dispersion liquid to obtain a mixed material liquid; Spray granulation to obtain granulated powder; press the granulated powder to obtain a pressed silicon nitride ceramic microsphere green body; Put the green ball into the crucible and carry out the atmosphere pressure sintering and hot isostatic pressing sintering successively to obtain the silicon nitride green green ball; 5 to 50 times the diameter; the crucible is a crucible with a multi-layer side wall, and the multi-layer side wall includes a graphite outer wall, an intermediate wall and an inner wall from outside to inside; The extension direction of the same, the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than the diameter of the silicon nitride ceramic green ball; the silicon nitride green ball is carried out Grinding to obtain high-precision silicon nitride ceramic microspheres.
本发明将压制氮化硅陶瓷微球素坯与较大尺寸氮化硅陶瓷素坯球一起进行烧结，由于较大尺寸氮化硅陶瓷素坯球的直径大于压制氮化硅陶瓷微球素坯的直径，装入坩埚时，压制氮化硅陶瓷微球素坯会填充到大尺寸氮化硅陶瓷素坯球的间隙内，有利于压制氮化硅陶瓷微球素坯在烧结过程中受热均匀；此外，本发明采用多层侧壁坩埚进行烧结，且中间壁和内部的材质均为氮化硅，氮化硅可吸收部分热量，防止压制氮化硅陶瓷微球素坯局部受热过高造成晶粒异常长大、表面出现白坑、雪花等缺陷。此外，本发明通过依次进行气氛压力烧结和热等静压烧结，相较于单一的气氛压 力烧结或热等静压烧结，能够进一步提高氮化硅陶瓷微球的致密度，减少气孔和异常大晶粒缺陷，从而提高Si 3N 4陶瓷球的力学性能、稳定性和表面质量。 In the present invention, the pressed silicon nitride ceramic microsphere green body and the larger-sized silicon nitride ceramic green body ball are sintered together, because the diameter of the larger-sized silicon nitride ceramic green body ball is larger than the pressed silicon nitride ceramic microsphere green body diameter, when loaded into the crucible, the pressed silicon nitride ceramic microsphere green body will be filled into the gap of the large-size silicon nitride ceramic green body ball, which is beneficial to the pressed silicon nitride ceramic microsphere green body to be heated evenly during the sintering process In addition, the present invention adopts the multilayer side wall crucible to carry out sintering, and the material of the middle wall and the interior is silicon nitride, and silicon nitride can absorb part of heat, prevents the compacted silicon nitride ceramic microsphere blank from being overheated locally and causes The crystal grains grow abnormally, and defects such as white pits and snowflakes appear on the surface. In addition, by performing atmosphere pressure sintering and hot isostatic pressing sequentially, the present invention can further improve the density of silicon nitride ceramic microspheres, reduce pores and abnormally large Grain defects, thereby improving the mechanical properties, stability and surface quality of Si 3 N 4 ceramic balls.
进一步的，本发明通过控制烧结助剂的质量为氮化硅粉和烧结助剂总质量的3～5％，烧结时烧结助剂与颗粒表层物质反应形成的氮氧化物液相少，烧结后在晶界间留下的玻璃相少，陶瓷球纯度高，有利于提高氮化硅陶瓷微球的力学性能。Further, the present invention controls the quality of the sintering aid to be 3 to 5% of the total mass of the silicon nitride powder and the sintering aid. During sintering, the nitrogen oxide liquid phase formed by the reaction of the sintering aid and the particle surface material is less, and after sintering There are few glass phases left between the grain boundaries, and the ceramic balls have high purity, which is beneficial to improving the mechanical properties of the silicon nitride ceramic microspheres.
实施例的结果表明，本发明制备的高精度氮化硅陶瓷微球维氏硬度HV10最高达到1524kg/mm 2，断裂韧性最高达到8.6MPa·m 1/2，表面粗糙度0.006μm≤Ra≤0.008μm，球直径变动量0.03μm≤V Dw≤0.08μm，球形误差0.03μm≤△S ph≤0.08μm，各项性能指标均符合GB/T308.2-2010/ISO3290-2：2008《滚动轴承珠第2部分：氮化硅陶瓷微珠》标准要求的G3级标准要求。 The results of the examples show that the Vickers hardness HV10 of the high-precision silicon nitride ceramic microspheres prepared by the present invention can reach up to 1524kg/mm 2 , the fracture toughness can reach up to 8.6MPa·m 1/2 , and the surface roughness is 0.006μm≤Ra≤0.008 μm, ball diameter variation 0.03μm≤V Dw ≤0.08μm, spherical error 0.03μm≤△S ph ≤0.08μm, all performance indicators are in line with GB/T308.2-2010/ISO3290-2: 2008 "Rolling Bearing Ball Part 2: G3 level standard requirements for silicon nitride ceramic microbeads.
说明书附图Instructions attached
图1为本发明烧结所用坩埚的结构示意图；Fig. 1 is the structural representation of crucible used for sintering of the present invention;
图2为对比例1制备的其中一个氮化硅微球的照片；Fig. 2 is wherein a photo of silicon nitride microspheres prepared in comparative example 1;
图3为对比例1制备的其中一个氮化硅微球的扫描电镜图。3 is a scanning electron microscope image of one of the silicon nitride microspheres prepared in Comparative Example 1.
具体实施方式Detailed ways
本发明提供了一种高精度氮化硅陶瓷微球的制备方法，包括以下步骤：The invention provides a method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps:
将氮化硅粉、烧结助剂和分散液进行球磨混合，得到混合料液；Ball milling and mixing the silicon nitride powder, sintering aid and dispersion liquid to obtain a mixed material liquid;
将所述混合料液进行喷雾造粒，得到造粒粉；Spraying and granulating the mixed material liquid to obtain granulated powder;
将所述造粒粉压制成型，得到压制氮化硅陶瓷微球素坯；Compressing the granulated powder to obtain a pressed silicon nitride ceramic microsphere green body;
将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入坩埚中依次进行气氛压力烧结和热等静压烧结，得到氮化硅毛坯球；所述较大尺寸氮化硅陶瓷素坯球的直径为压制氮化硅陶瓷微球素坯的直径的5～50倍；所述坩埚为多层侧壁的坩埚，所述多层侧壁由外到内依次包括石墨外壁、中间壁和内壁；所述中间壁和内壁的延伸方向与坩埚外壁的延 伸方向一致，所述中间壁和内壁的材质为氮化硅；相邻层侧壁之间的间隙大于较大尺寸氮化硅陶瓷素坯球的直径；Put the pressed silicon nitride ceramic microsphere green body and the silicon nitride ceramic green body ball with larger size into the crucible to carry out atmosphere pressure sintering and hot isostatic pressing sintering sequentially to obtain the silicon nitride green body ball; the larger The diameter of the silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body; the crucible is a crucible with multi-layer side walls, and the multi-layer side walls are sequentially It includes graphite outer wall, middle wall and inner wall; the extension direction of the middle wall and the inner wall is consistent with the extension direction of the crucible outer wall, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than that of the crucible The diameter of the large-size silicon nitride ceramic green ball;
将所述氮化硅毛坯球进行磨削加工，得到高精度氮化硅陶瓷微球。Grinding the silicon nitride rough balls to obtain high-precision silicon nitride ceramic microspheres.
在本发明中，未经特殊说明，所用原料均为本领域熟知的市售商品。In the present invention, unless otherwise specified, the raw materials used are commercially available products well known in the art.
本发明将氮化硅粉、烧结助剂和分散液进行球磨混合，得到混合料液。In the invention, the silicon nitride powder, the sintering aid and the dispersion liquid are ball-milled and mixed to obtain the mixed material liquid.
在本发明中，所述烧结助剂的质量优选为氮化硅粉和烧结助剂总质量的3～5％；所述烧结助剂优选包括氧化铝、氧化镧、氧化钕、氧化镱、氧化铒和氧化钐中的一种或多种，更优选为氧化铝3％+氧化镧2％、氧化铝2％+氧化镥1％、或氧化铝2％+氧化铒2％。本段中的百分比均指的是相对于氮化硅粉和烧结助剂的总质量而言。In the present invention, the mass of the sintering aid is preferably 3-5% of the total mass of the silicon nitride powder and the sintering aid; the sintering aid preferably includes alumina, lanthanum oxide, neodymium oxide, ytterbium oxide, oxide One or more of erbium and samarium oxide, more preferably 3% alumina + 2% lanthanum oxide, 2% alumina + 1% lutetium oxide, or 2% alumina + 2% erbium oxide. The percentages in this paragraph refer to the total mass of silicon nitride powder and sintering aid.
在本发明中，所述分散液优选为无水乙醇；所述分散液的质量与氮化硅粉和烧结助剂的总质量之比优选为(3～4)：1。In the present invention, the dispersion liquid is preferably absolute ethanol; the ratio of the mass of the dispersion liquid to the total mass of the silicon nitride powder and the sintering aid is preferably (3-4):1.
在本发明中，所述球磨混合采用的研磨球优选为氮化硅研磨球，所述氮化硅研磨球的质量与氮化硅粉和烧结助剂总质量的比优选为(1.5～3):1，更优选为2:1。在本发明中，所述球磨混合的时间优选为18～24h。在本发明中，所述球磨混合优选采用滚筒磨。本发明对所述球磨混合的转速没有特殊要求，采用本领域熟知的转速即可。In the present invention, the grinding balls used in the ball mill mixing are preferably silicon nitride grinding balls, and the ratio of the mass of the silicon nitride grinding balls to the total mass of silicon nitride powder and sintering aid is preferably (1.5-3) :1, more preferably 2:1. In the present invention, the time for ball milling and mixing is preferably 18-24 hours. In the present invention, the mixing by ball milling is preferably by drum milling. In the present invention, there is no special requirement on the rotating speed of the ball milling, and the rotating speed well known in the art can be used.
得到混合料液后，本发明将所述混合料液进行喷雾造粒，得到造粒粉。在本发明中，所述喷雾造粒优选采用压力喷雾造粒的方式。本发明优选在喷雾造粒塔中进行喷雾造粒。本发明对所述喷雾造粒的条件没有特殊要求，采用本领域熟知的喷雾造粒条件即可。在本发明的实施例中，所用喷雾造粒塔进口温度为190℃，喷片孔径为0.9mm。在本发明中，所述造粒粉的粒径优选为50～100μm。本发明利用喷雾造粒提高造粒粉的流动性，有利于后续压制成型。After the mixed material liquid is obtained, the present invention sprays and granulates the mixed material liquid to obtain granulated powder. In the present invention, the spray granulation is preferably in the form of pressure spray granulation. The present invention preferably carries out spray granulation in a spray granulation tower. The present invention has no special requirements on the conditions of the spray granulation, and the spray granulation conditions well known in the art can be used. In the embodiment of the present invention, the inlet temperature of the spray granulation tower used is 190° C., and the hole diameter of the nozzle is 0.9 mm. In the present invention, the particle size of the granulated powder is preferably 50-100 μm. The invention utilizes spray granulation to improve the fluidity of the granulated powder, which is beneficial to subsequent compression molding.
得到造粒粉后，本发明将所述造粒粉压制成型，得到压制氮化硅陶瓷微球素坯。在本发明中，所述压制成型优选采用中国专利CN202023003181.3中所述的陶瓷微珠成型装置压制成型。本发明优选根据压制氮化硅陶瓷微球素坯的尺寸选择合适尺寸的条状模具盘，圆柱形滚轮模具转速优选为5～10r/min。在本发明中，所述压制氮化硅陶瓷微球素坯的直径优选为0.8～4mm。After the granulated powder is obtained, the present invention compresses the granulated powder to obtain a pressed silicon nitride ceramic microsphere compact. In the present invention, the compression molding is preferably performed using the ceramic microbead molding device described in Chinese patent CN202023003181.3. In the present invention, it is preferable to select a strip-shaped mold plate of a suitable size according to the size of the pressed silicon nitride ceramic microsphere green body, and the rotational speed of the cylindrical roller mold is preferably 5-10 r/min. In the present invention, the diameter of the pressed silicon nitride ceramic microsphere green body is preferably 0.8-4mm.
得到压制氮化硅陶瓷微球素坯后，本发明将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入坩埚中依次进行气氛压力烧结和热等静压烧结，得到氮化硅毛坯球。After the pressed silicon nitride ceramic microsphere green body is obtained, the present invention puts the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body balls into a crucible to carry out atmosphere pressure sintering and hot isostatic sintering successively. Press and sinter to obtain silicon nitride green balls.
本发明对所述较大尺寸氮化硅陶瓷素坯球的化学组成没有特殊要求，本领域熟知的氮化硅陶瓷素坯球均可。在本发明中，所述较大尺寸氮氮化硅陶瓷素坯球优选使用旋转压机利用上模与下模冲压方式干压成型。The present invention has no special requirements on the chemical composition of the larger-sized silicon nitride ceramic green balls, and any silicon nitride ceramic green balls known in the art can be used. In the present invention, the relatively large-sized silicon nitride nitride ceramic green ball is preferably formed by dry pressing using a rotary press by means of an upper die and a lower die.
在本发明中，所述较大尺寸氮化硅陶瓷素坯球的直径为压制氮化硅陶瓷微球素坯的直径的5～50倍，更进一步优选的，所述较大尺寸氮化硅陶瓷素坯球的直径为20～35mm，所述压制氮化硅陶瓷微球素坯的直径为0.8～4mm。在本发明中，所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球的质量比优选为1：(1～3)，更优选为1：(1.5～2.5)。本发明将压制氮化硅陶瓷微球素坯与较大尺寸氮化硅陶瓷素坯球一起依次进行气氛压力烧结和热等静压烧结，由于较大尺寸氮化硅陶瓷素坯球的直径大于压制氮化硅陶瓷微球素坯的直径，陶瓷球装入坩埚时，压制氮化硅陶瓷微球素坯会填充到较大尺寸氮化硅陶瓷素坯球的间隙内，有利于压制氮化硅陶瓷微球素坯在烧结过程中受热均匀，防止局部受热过高造成晶粒异常长大、表面出现白坑、雪花等缺陷。In the present invention, the diameter of the larger-sized silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body. More preferably, the larger-sized silicon nitride The diameter of the ceramic green ball is 20-35 mm, and the diameter of the pressed silicon nitride ceramic microsphere green body is 0.8-4 mm. In the present invention, the mass ratio of the pressed silicon nitride ceramic microsphere green body to the larger-sized silicon nitride ceramic green body ball is preferably 1: (1-3), more preferably 1: (1.5-2.5) . The present invention carries out atmosphere pressure sintering and hot isostatic pressing sintering successively together with the larger-sized silicon nitride ceramic green body pressed silicon nitride ceramic microsphere green body, because the diameter of larger-sized silicon nitride ceramic green body ball is larger than The diameter of the pressed silicon nitride ceramic microsphere green body, when the ceramic ball is loaded into the crucible, the pressed silicon nitride ceramic microsphere green body will be filled into the gap of the larger size silicon nitride ceramic green body ball, which is beneficial to the pressing and nitriding The silicon ceramic microsphere green body is evenly heated during the sintering process to prevent abnormal grain growth, white pits, snowflakes and other defects on the surface caused by excessive local heating.
在本发明中，所述坩埚为多层侧壁的坩埚，如图1所示，所述多层侧壁由外到内依次包括石墨外壁、中间壁和内壁；所述中间壁和内壁的延伸方向与坩埚外壁的延伸方向一致，所述中间壁和内壁的材质为氮化硅；相邻层侧壁之间的间隙大于氮化硅陶瓷素坯球的直径。在本发明中，所述多层侧壁坩埚为一体结构，石墨外壁、中间壁和内壁共用同一个坩埚底。In the present invention, the crucible is a crucible with multilayer side walls. As shown in Figure 1, the multilayer side walls include graphite outer wall, middle wall and inner wall from outside to inside; the extension of the middle wall and inner wall The direction is consistent with the extension direction of the outer wall of the crucible, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than the diameter of the silicon nitride ceramic green ball. In the present invention, the multi-layer side wall crucible has an integrated structure, and the graphite outer wall, middle wall and inner wall share the same crucible bottom.
在本发明中，所述内壁的厚度优选为2～4mm，内壁形成的同心圆的内径优选为90～100mm；所述中间壁的厚度优选为3～5mm，中间壁形成的同心圆的内径优选为180～200mm；所述石墨外壁的厚度优选为8～10mm，形成的同心圆的内径优选为300～320mm。在本发明中，所述坩埚的底厚优选为6～8mm。在本发明中，所述坩埚各个侧壁的高度优选相同，高度优选为15～17mm。In the present invention, the thickness of the inner wall is preferably 2 to 4 mm, and the inner diameter of the concentric circle formed by the inner wall is preferably 90 to 100 mm; the thickness of the intermediate wall is preferably 3 to 5 mm, and the inner diameter of the concentric circle formed by the intermediate wall is preferably 180-200 mm; the thickness of the graphite outer wall is preferably 8-10 mm, and the inner diameter of the formed concentric circles is preferably 300-320 mm. In the present invention, the bottom thickness of the crucible is preferably 6-8mm. In the present invention, the height of each side wall of the crucible is preferably the same, and the height is preferably 15-17 mm.
在本发明中，烧结时优选将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入多层侧壁坩埚的层间和内壁形成的腔体中。本发明 采用多层侧壁的坩埚依次进行气氛压力烧结和热等静压烧结，且中间壁和内部的材质均为氮化硅，氮化硅可吸收部分热量，防止压制氮化硅陶瓷微球素坯局部受热过高造成晶粒异常长大、表面出现白坑、雪花等缺陷。In the present invention, during sintering, the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body balls are preferably packed into the cavity formed by the interlayer and inner wall of the multilayer sidewall crucible. The present invention uses a crucible with multi-layer side walls to carry out atmosphere pressure sintering and hot isostatic pressing sintering sequentially, and the material of the middle wall and the inside is silicon nitride, which can absorb part of the heat and prevent the pressing of silicon nitride ceramic microspheres. Partial heating of the green body is too high, resulting in abnormal grain growth, white pits, snowflakes and other defects on the surface.
在本发明中，所述气氛压力烧结的温度优选为1700～1800℃，更优选为1720～1780℃；保温时间优选为1～3h，更优选为2h；所述气氛压力烧结优选在氮气保护下进行。本发明优选自室温升温至所述气氛压力烧结的温度，升温速率优选为5～20℃/min。本发明利用气氛压力烧结得到无开口气孔的Si 3N 4陶瓷。 In the present invention, the temperature of the atmosphere pressure sintering is preferably 1700-1800°C, more preferably 1720-1780°C; the holding time is preferably 1-3h, more preferably 2h; the atmosphere pressure sintering is preferably under the protection of nitrogen conduct. In the present invention, the temperature is preferably raised from room temperature to the temperature of the atmosphere pressure sintering, and the heating rate is preferably 5-20° C./min. The invention utilizes atmosphere pressure sintering to obtain Si 3 N 4 ceramics without open pores.
待完成气氛压力烧结后，本发明优选冷却到室温，然后再进行热等静压烧结。在本发明中，所述热等静压烧结的温度优选为1800～1850℃，保温时间优选为0.5～1h，所述热等静压烧结优选在氮气保护下进行，所述热等静压烧结时氮气的压力优选为200～210MPa。在本发明中，升温至所述热等静压烧结的温度的升温速率优选为5～20℃/min。本发明在气氛压力烧结后进行热等静压烧结，能够进一步提高氮化硅陶瓷微球的致密度，减少异常大晶粒缺陷，从而提高Si 3N 4陶瓷球的致密度、力学性能、稳定性和表面质量。 After the atmosphere pressure sintering is completed, the present invention is preferably cooled to room temperature, and then hot isostatic pressing sintering is performed. In the present invention, the temperature of the hot isostatic pressing sintering is preferably 1800-1850°C, the holding time is preferably 0.5-1h, the hot isostatic pressing sintering is preferably carried out under nitrogen protection, the hot isostatic pressing sintering The pressure of the nitrogen gas is preferably 200 to 210 MPa. In the present invention, the temperature increase rate to the temperature of the hot isostatic pressing sintering is preferably 5-20° C./min. The present invention performs hot isostatic pressing sintering after atmospheric pressure sintering, which can further increase the density of silicon nitride ceramic microspheres and reduce abnormally large grain defects, thereby improving the density, mechanical properties, and stability of Si 3 N 4 ceramic balls. and surface quality.
在本发明中，所述气氛压力烧结和热等静压烧结均采用本发明所述的多层侧壁坩埚。In the present invention, both the atmosphere pressure sintering and the hot isostatic pressing sintering adopt the multi-layer side wall crucible of the present invention.
完成所述热等静压烧结后，本发明去除较大尺寸氮化硅陶瓷素坯球，得到氮化硅毛坯球。After the hot isostatic pressing sintering is completed, the present invention removes larger-sized silicon nitride ceramic green balls to obtain silicon nitride green balls.
得到氮化硅毛坯球后，本发明将所述氮化硅毛坯球进行磨削加工，得到高精度氮化硅陶瓷微球。在本发明中，所述磨削加工优选包括依次进行粗磨、细磨、精磨、精研和超精研。在本发明中，所述磨削加工优选采用中国专利CN 202021836565.0公开的氮化硅陶瓷微珠批量加工装置进行。在本发明中，所述磨削加工装置的上、下研磨板均为铸铁板，规格优选为Φ660mm×Φ420mm。After the silicon nitride green balls are obtained, the present invention grinds the silicon nitride green balls to obtain high-precision silicon nitride ceramic microspheres. In the present invention, the grinding process preferably includes rough grinding, fine grinding, fine grinding, fine grinding and superfinishing in sequence. In the present invention, the grinding process is preferably performed using the silicon nitride ceramic microbead batch processing device disclosed in Chinese patent CN 202021836565.0. In the present invention, the upper and lower grinding plates of the grinding device are all cast iron plates, and the size is preferably Φ660mm×Φ420mm.
在本发明中，所述粗磨时，上、下研磨板间施加的压力优选为(0.8～1)×10KN，主轴转速优选为100～120r/min，所述粗磨的加工余量优选为250～350μm。In the present invention, during the rough grinding, the pressure applied between the upper and lower grinding plates is preferably (0.8～1)×10KN, the spindle speed is preferably 100～120r/min, and the machining allowance of the rough grinding is preferably 250～350μm.
在本发明中，所述细磨时，上、下研磨板间施加的压力优选为 (0.6～0.9)×10KN，主轴转速优选为80～100r/min，所述细磨的加工余量优选为≥150μm且＜250μm。In the present invention, during the fine grinding, the pressure applied between the upper and lower grinding plates is preferably (0.6～0.9)×10KN, the spindle speed is preferably 80～100r/min, and the machining allowance of the fine grinding is preferably ≥150μm and <250μm.
在本发明中，所述精磨时，上、下研磨板间施加的压力优选为(0.4～0.7)×10KN，主轴转速优选为70～80r/min，所述精磨的加工余量优选为≥50μm且＜100μm。In the present invention, during the fine grinding, the pressure applied between the upper and lower grinding plates is preferably (0.4～0.7)×10KN, the spindle speed is preferably 70～80r/min, and the machining allowance of the fine grinding is preferably ≥50μm and <100μm.
在本发明中，所述精研时，上、下研磨板间施加的压力优选为(0.3～0.6)×10KN，主轴转速优选为60～70r/min，所述精研的加工余量优选为≥30μm且＜50μm。In the present invention, during the lapping, the pressure applied between the upper and lower grinding plates is preferably (0.3-0.6) × 10KN, the spindle speed is preferably 60-70r/min, and the machining allowance of the lapping is preferably ≥30μm and <50μm.
在本发明中，所述超精研时，上、下研磨板间施加的压力优选为(0.1～0.3)×10KN，主轴转速优选为50～60r/min，所述超精研的加工余量为0，即达到目标尺寸。In the present invention, during the superfinishing, the pressure applied between the upper and lower grinding plates is preferably (0.1～0.3)×10KN, the spindle speed is preferably 50～60r/min, and the machining allowance of the superfinishing If it is 0, the target size is reached.
本发明提供了上述方案所述制备方法制备得到的高精度氮化硅陶瓷微球，所述高精度氮化硅陶瓷微球的表面粗糙度Ra满足：0.006μm≤Ra≤0.008μm，球直径变动量VDw满足：0.03μm≤VDw≤0.08μm，球形误差△Sph满足：0.03μm≤△Sph≤0.08μm。在本发明中，所述高精度氮化硅陶瓷微球维氏硬度HV10最高达到1480kg/mm 2，断裂韧性最高达到8MPa·m 1/2，各项性能指标均符合GB/T308.2-2010/ISO3290-2：2008《滚动轴承珠第2部分：氮化硅陶瓷微珠》标准要求的G3级标准要求。在本发明中，所述高精度氮化硅陶瓷微球的尺寸优选为0.4～1mm。 The present invention provides high-precision silicon nitride ceramic microspheres prepared by the preparation method described in the above proposal. The surface roughness Ra of the high-precision silicon nitride ceramic microspheres satisfies: 0.006μm≤Ra≤0.008μm, and the ball diameter varies The quantity VDw satisfies: 0.03μm≤VDw≤0.08μm, and the spherical error △Sph satisfies: 0.03μm≤△Sph≤0.08μm. In the present invention, the Vickers hardness HV10 of the high-precision silicon nitride ceramic microspheres can reach up to 1480kg/mm 2 , and the fracture toughness can reach up to 8MPa·m 1/2 , and all performance indicators conform to GB/T308.2-2010 /ISO3290-2:2008 "Rolling Bearing Balls Part 2: Silicon Nitride Ceramic Microballs" standard requirements of the G3 level standard requirements. In the present invention, the size of the high-precision silicon nitride ceramic microspheres is preferably 0.4-1 mm.
本发明提供了上述方案所述高精度氮化硅陶瓷微球在牙钻轴承中的应用。The present invention provides the application of the high-precision silicon nitride ceramic microspheres described in the above scheme in dental drill bearings.
下面结合实施例对本发明提供的高精度氮化硅陶瓷微球及其制备方法和应用进行详细的说明，但是不能把它们理解为对本发明保护范围的限定。The high-precision silicon nitride ceramic microspheres provided by the present invention and their preparation methods and applications will be described in detail below in conjunction with the examples, but they should not be understood as limiting the protection scope of the present invention.
以下实施例所用多层侧壁坩埚的规格为：The specifications of the multilayer sidewall crucible used in the following examples are:
内壁的厚度为3mm，内壁形成的同心圆的内径为100mm；中间壁的厚度为4mm，中间壁形成的同心圆的内径为180mm；石墨外壁的厚度为10mm，形成的同心圆的内径为320mm。多层侧壁坩埚的底厚为6mm，多层侧壁坩埚各个侧壁的高度相同，为15mm。The thickness of the inner wall is 3mm, and the inner diameter of the concentric circle formed by the inner wall is 100mm; the thickness of the middle wall is 4mm, and the inner diameter of the concentric circle formed by the middle wall is 180mm; the thickness of the graphite outer wall is 10mm, and the inner diameter of the formed concentric circle is 320mm. The bottom thickness of the multilayer sidewall crucible is 6mm, and the height of each sidewall of the multilayer sidewall crucible is the same, which is 15mm.
实施例1Example 1
(1)以2wt％含量的氧化铝、2wt％含量的氧化铒和96wt％含量的氮化硅粉作为粉料，无水乙醇(重量为粉料总重量的2倍)为分散液，将粉料、无水乙醇和氮化硅研磨球(重量为粉料总重量的2倍)放入滚筒磨中进行球磨混合，混合时间为24h，得到混合料液；(1) With the aluminum oxide of 2wt% content, the erbium oxide of 2wt% content and the silicon nitride powder of 96wt% content as powder, dehydrated alcohol (weight is 2 times of powder gross weight) is dispersion liquid, powder Material, absolute ethanol and silicon nitride grinding balls (weight is 2 times of the total weight of the powder) were put into the drum mill for ball milling and mixing, and the mixing time was 24h to obtain the mixed material liquid;
(2)将所述混合料液通过喷雾造粒塔采用压力喷雾造粒方式获得造粒粉，所用喷雾造粒塔进口温度为190℃，喷片孔径为0.9mm，得到粒径为50～100μm的球形颗粒；(2) Pass the mixed material liquid through a spray granulation tower and adopt pressure spray granulation to obtain granulated powder. The inlet temperature of the spray granulation tower used is 190° C., and the aperture of the spray sheet is 0.9 mm to obtain a particle size of 50 to 100 μm. spherical particles;
(3)使用CN 202023003181.3中所述陶瓷微珠成型装置将喷雾造粉压制成型，压制氮化硅陶瓷微球素坯尺寸为2.0～2.1mm；(3) Use the ceramic microsphere forming device described in CN 202023003181.3 to press and form the spray powder, and the size of the pressed silicon nitride ceramic microsphere green body is 2.0-2.1mm;
(4)将压制氮化硅陶瓷微球素坯与直径为20mm的氮化硅陶瓷素坯球按照质量比1:2装入多层侧壁坩埚内，放于气氛压力烧结炉中，烧结温度为1790℃，升温速率为8℃/min，最高温保温时间为1.5h，烧结过程采用氮气常压保护；热等静压烧结温度为1830℃，升温速率为10℃/min，最高温保温时间为1小时，烧结过程中氮气压力为200MPa，得到氮化硅毛坯球；(4) Put the pressed silicon nitride ceramic microsphere green body and the silicon nitride ceramic green body ball with a diameter of 20mm into the multi-layer side wall crucible according to the mass ratio of 1:2, put them in the atmosphere pressure sintering furnace, and the sintering temperature The temperature is 1790°C, the heating rate is 8°C/min, the highest temperature holding time is 1.5h, and the sintering process is protected by nitrogen atmospheric pressure; the hot isostatic pressing sintering temperature is 1830°C, the heating rate is 10°C/min, and the highest temperature holding time is For 1 hour, the nitrogen pressure is 200MPa during the sintering process to obtain silicon nitride green balls;
(5)将所述氮化硅毛坯球进行粗磨、细磨、精磨、精研和超精研加工，上、下研磨板均为铸铁材质铸铁板，规格为Φ660mm×Φ420mm，其中，粗磨工序上、下研磨板间施加的压力为1×10KN，主轴转速为110r/min；细磨工序上、下研磨板间施加的压力为0.9×10KN，主轴转速为90r/min；精磨工序上、下研磨板间施加的压力为0.7×10KN之间，主轴转速为80r/min；精研工序上、下研磨板间施加的压力为0.6×10KN，主轴转速为70r/min；超精研工序上、下研磨板间施加的压力为0.3×10KN，主轴转速为60r/min，得到Φ1mm氮化硅陶瓷微球成品。(5) The silicon nitride rough ball is subjected to rough grinding, fine grinding, fine grinding, fine grinding and super-finishing processing, and the upper and lower grinding plates are made of cast iron with a specification of Φ660mm×Φ420mm. The pressure applied between the upper and lower grinding plates in the grinding process is 1×10KN, and the spindle speed is 110r/min; the pressure applied between the upper and lower grinding plates in the fine grinding process is 0.9×10KN, and the spindle speed is 90r/min; The pressure applied between the upper and lower grinding plates is 0.7×10KN, the spindle speed is 80r/min; the pressure applied between the upper and lower grinding plates in the lapping process is 0.6×10KN, and the spindle speed is 70r/min; The pressure applied between the upper and lower grinding plates in the process is 0.3×10KN, the spindle speed is 60r/min, and the finished product of Φ1mm silicon nitride ceramic microspheres is obtained.
实施例2Example 2
(1)将3wt％含量的氧化铝、2wt％含量的氧化镧和95wt％含量的氮化硅作为粉料，无水乙醇(重量为粉料总重量的2倍)为分散液，将粉料、分散液和氮化硅研磨球(重量为粉料总重量的2倍)放入滚筒磨中进行球磨混合，混合时间为24h，得到混合料液；(1) the aluminum oxide of 3wt% content, the lanthanum oxide of 2wt% content and the silicon nitride of 95wt% content are used as powder, and dehydrated alcohol (weight is 2 times of powder gross weight) is dispersion liquid, and powder , the dispersion liquid and silicon nitride grinding balls (weight is 2 times of the total weight of the powder) are put into the drum mill for ball milling and mixing, and the mixing time is 24h to obtain the mixed material liquid;
(2)将所述混合料液通过喷雾造粒塔采用压力喷雾造粒方式获得造粒粉，所用喷雾造粒塔进口温度为190℃，喷片孔径为0.9mm，得到粒径为50～100μm的球形颗粒；(2) Pass the mixed material liquid through a spray granulation tower and adopt pressure spray granulation to obtain granulated powder. The inlet temperature of the spray granulation tower used is 190° C., and the aperture of the spray sheet is 0.9 mm to obtain a particle size of 50 to 100 μm. spherical particles;
(3)使用CN 202023003181.3中所述陶瓷微珠成型装置将喷雾造粉压制成型，压制氮化硅陶瓷微球素坯尺寸为1.3～1.4mm；(3) Use the ceramic bead forming device described in CN 202023003181.3 to press and form the spray powder, and the size of the pressed silicon nitride ceramic microsphere green body is 1.3-1.4mm;
(4)将压制氮化硅陶瓷微球素坯与直径20mm的氮化硅陶瓷素坯球按照质量比1:2.5装入多层侧壁坩埚内，放于气氛压力烧结炉中，烧结温度为1760℃，升温速率为9℃/min，最高温保温时间为2h，烧结过程采用氮气常压保护；热等静压烧结温度为1800℃，升温速率为8℃/min，最高温保温时间为1小时，总烧结时间为10小时，烧结过程中氮气压力为200MPa，得到氮化硅毛坯球；(4) Put the pressed silicon nitride ceramic microsphere green body and the silicon nitride ceramic green body ball with a diameter of 20 mm into a multi-layer side wall crucible according to the mass ratio of 1:2.5, and put them in an atmosphere pressure sintering furnace at a sintering temperature of 1760°C, the heating rate is 9°C/min, the highest temperature holding time is 2h, and the sintering process is protected by nitrogen atmospheric pressure; the hot isostatic pressing sintering temperature is 1800°C, the heating rate is 8°C/min, and the highest temperature holding time is 1 hours, the total sintering time is 10 hours, and the nitrogen pressure is 200MPa during the sintering process to obtain silicon nitride green balls;
(5)将所述氮化硅毛坯球进行粗磨、细磨、精磨、精研、超精研加工，上、下研磨板均为铸铁材质铸铁板，规格为Φ660mm×Φ420mm，其中，粗磨工序上、下研磨板间施加的压力为0.8×10KN，主轴转速为110r/min；细磨工序上、下研磨板间施加的压力为0.7×10KN之间，主轴转速为90r/min；精磨工序上、下研磨板间施加的压力为0.6×10KN之间，主轴转速为70r/min；精研工序上、下研磨板间施加的压力为0.5×10KN之间，主轴转速为60r/min；超精研工序上、下研磨板间施加的压力为0.2×10KN之间，主轴转速为60r/min，得到Φ0.8mm氮化硅陶瓷微球成品。(5) Roughly grind, finely grind, finely grind, finely grind, and ultrafinely grind the silicon nitride rough balls. The upper and lower grinding plates are made of cast iron with a specification of Φ660mm×Φ420mm. The pressure applied between the upper and lower grinding plates in the grinding process is 0.8×10KN, and the spindle speed is 110r/min; the pressure applied between the upper and lower grinding plates in the fine grinding process is between 0.7×10KN, and the spindle speed is 90r/min; The pressure applied between the upper and lower grinding plates in the grinding process is between 0.6×10KN, and the spindle speed is 70r/min; the pressure applied between the upper and lower grinding plates in the finishing process is between 0.5×10KN, and the spindle speed is 60r/min ; In the superfinishing process, the pressure applied between the upper and lower grinding plates is between 0.2×10KN, the spindle speed is 60r/min, and the finished product of Φ0.8mm silicon nitride ceramic microspheres is obtained.
实施例3Example 3
(1)将2wt％含量的氧化铝、1wt％含量的氧化镥和97wt％含量的氮化硅粉作为粉料，无水乙醇(重量为粉料总重量的2倍)为分散液，将粉料、无水乙醇和氮化硅研磨球(重量为粉料总重量的2倍)放入滚筒磨中进行球磨混合，混合时间为24h，得到混合料液；(1) the aluminum oxide of 2wt% content, the lutetium oxide of 1wt% content and the silicon nitride powder of 97wt% content are used as powder, and dehydrated alcohol (weight is 2 times of powder gross weight) is dispersion liquid, powder Material, absolute ethanol and silicon nitride grinding balls (weight is 2 times of the total weight of the powder) were put into the drum mill for ball milling and mixing, and the mixing time was 24h to obtain the mixed material liquid;
(2)将所述混合料液通过喷雾造粒塔采用压力喷雾造粒方式获得造粒粉，所用喷雾造粒塔进口温度为190℃，喷片孔径为0.9mm，得到粒径为50～100μm的球形颗粒；(2) Pass the mixed material liquid through a spray granulation tower and adopt pressure spray granulation to obtain granulated powder. The inlet temperature of the spray granulation tower used is 190° C., and the aperture of the spray sheet is 0.9 mm to obtain a particle size of 50 to 100 μm. spherical particles;
(3)使用CN 202023003181.3中所述陶瓷微珠成型装置将喷雾造粉压制成型，压制氮化硅陶瓷微球素坯尺寸为0.8～0.9mm；(3) Use the ceramic bead forming device described in CN 202023003181.3 to press and form the spray powder, and the size of the pressed silicon nitride ceramic microsphere green body is 0.8-0.9mm;
(4)将压制氮化硅陶瓷微球素坯与直径Φ20mm氮化硅陶瓷素坯球按照质量比1:2.5装入多层侧壁坩埚内，放于气氛压力烧结炉中，烧结温度为1750℃，升温速率为10℃/min，最高温保温时间为2h，烧结过程采用氮气常压保护；热等静压烧结温度为1750℃，升温速率为12℃/min，最高温保温时间为0.5小时，总烧结时间为9.5小时，烧结过程中氮气压力为200MPa，得到氮化硅毛坯球；(4) Put the pressed silicon nitride ceramic microsphere green body and the silicon nitride ceramic green body ball with a diameter of Φ20 mm into a multi-layer side wall crucible according to the mass ratio of 1:2.5, and put it in an atmosphere pressure sintering furnace, and the sintering temperature is 1750 ℃, the heating rate is 10°C/min, the highest temperature holding time is 2h, and the sintering process is protected by nitrogen atmospheric pressure; the hot isostatic pressing sintering temperature is 1750°C, the heating rate is 12°C/min, and the highest temperature holding time is 0.5 hours , the total sintering time is 9.5 hours, the nitrogen pressure is 200MPa during the sintering process, and silicon nitride green balls are obtained;
(5)将所述氮化硅毛坯球进行粗磨、细磨、精磨、精研、超精研加工，上、下研磨板均为铸铁材质铸铁板，规格为Φ660mm×Φ420mm，其中，粗磨工序上、下研磨板间施加的压力为0.8×10KN，主轴转速为100r/min；细磨工序上、下研磨板间施加的压力为0.6×10KN，主轴转速为80r/min；精磨工序上、下研磨板间施加的压力为0.4×10KN，主轴转速为70r/min；精研工序上、下研磨板间施加的压力为0.3×10KN，主轴转速为60r/min；超精研工序上、下研磨板间施加的压力为0.1×10KN，主轴转速为50r/min，得到Φ0.4mm氮化硅陶瓷微球成品。(5) Roughly grind, finely grind, finely grind, finely grind, and ultrafinely grind the silicon nitride rough balls. The upper and lower grinding plates are made of cast iron with a specification of Φ660mm×Φ420mm. The pressure applied between the upper and lower grinding plates in the grinding process is 0.8×10KN, and the spindle speed is 100r/min; the pressure applied between the upper and lower grinding plates in the fine grinding process is 0.6×10KN, and the spindle speed is 80r/min; The pressure applied between the upper and lower grinding plates is 0.4×10KN, and the spindle speed is 70r/min; the pressure applied between the upper and lower grinding plates in the lapping process is 0.3×10KN, and the spindle speed is 60r/min; , and the pressure applied between the lower grinding plates is 0.1×10KN, the spindle speed is 50r/min, and the finished product of Φ0.4mm silicon nitride ceramic microspheres is obtained.
对比例1Comparative example 1
与实施例1的区别仅在于使用普通单层坩埚。The difference from Example 1 is only that a common single-layer crucible is used.
对比例2Comparative example 2
与实施例1的区别仅在于烧结时未使用直径20mm的氮化硅陶瓷素坯球。The difference from Example 1 is only that silicon nitride ceramic green balls with a diameter of 20 mm are not used during sintering.
对比例3Comparative example 3
与实施例1的区别仅在于省去热等静压烧结。The difference from Example 1 is only that hot isostatic pressing sintering is omitted.
对比例4Comparative example 4
与实施例1的区别仅在于省去气氛压力烧结。The difference from Example 1 is only that the atmosphere pressure sintering is omitted.
对实施例1～3及对比例1～4的成品进行力学性能测试和精度测试，其中，力学性能测试参照ASTM F2094-2018a，精度测试参照GB/T308.2-2010/ISO3290-2：2008《滚动轴承珠第2部分：氮化硅陶瓷微珠》，测试结果见表1。The finished products of Examples 1-3 and Comparative Examples 1-4 were subjected to mechanical performance test and precision test, wherein, the mechanical performance test refers to ASTM F2094-2018a, and the precision test refers to GB/T308.2-2010/ISO3290-2:2008 " Rolling Bearing Balls Part 2: Silicon Nitride Ceramic Microballs", the test results are shown in Table 1.
表1实施例1～3及对比例1～4制备的氮化硅陶瓷球的力学性能和精度Table 1 The mechanical properties and precision of the silicon nitride ceramic balls prepared in Examples 1 to 3 and Comparative Examples 1 to 4
Figure PCTCN2022126295-appb-000001
Figure PCTCN2022126295-appb-000001
Figure PCTCN2022126295-appb-000002
Figure PCTCN2022126295-appb-000002
注：异常大晶粒只能通过扫描电镜观察，每批次球数量较大，无法统计比例，故在表1中未列出。Note: Abnormally large grains can only be observed by scanning electron microscopy, and the number of balls in each batch is large, and the proportion cannot be counted, so they are not listed in Table 1.
由表1可知，实施例1、2、3制备的氮化硅陶瓷微球致密度都达到99.7％以上，维氏硬度、断裂韧性及三点弯曲强度等材料性能达到ASTM F2094-2018a I级材料标准，精度等级达到GB/T308.2G3级标准，白坑及雪花缺陷比例均低于0.5％。对比例1制备的氮化硅陶瓷微球致密度达到99.53％，硬度仅达到ASTM F2094-2018a II级材料标准，断裂韧性及三点弯曲强度达到I级材料标准，精度等级达到GB/T308.2 G10级标准，白点及雪花比例分别为32％、18％；对比例2制备的氮化硅陶瓷微球致密度达到99.41％，硬度仅达到ASTM F2094-2018a II级材料标准，断裂韧性及三点弯曲强度达到I级材料标准，精度等级达到GB/T308.2 G10级标准，白点及雪花比例分别为35％、21％；对比例3制备的氮化硅陶瓷微球致密度仅达到95.11％，硬度低于ASTM F2094-2018a III级材料标准，断裂韧性达到II级材料标准，三点弯曲强度达到III级材料标准，精度等级达到GB/T308.2 G20级标准，白点及雪花比例分别为26％、13％；对比例4制备的氮化硅陶瓷微球致密度达到96.32％，硬度断裂韧性达到ASTM F2094-2018a II级材料标准，三点弯曲强度达到III级材料标准，精度等级达到GB/T308.2 G20级标准，白点及雪花比例分别为30％、10％。说明本发明通过采用气氛压力烧结与热等静压烧结相结合的烧结方式，采用较大尺寸的氮化硅陶瓷素坯球以及采用多层侧壁坩埚进行烧结，解决了氮化硅陶瓷微球存在气孔、异常大晶粒、表面凹坑及雪花等缺陷，实现了氮化硅 陶瓷微球的高精度制备。It can be seen from Table 1 that the density of the silicon nitride ceramic microspheres prepared in Examples 1, 2, and 3 all reached above 99.7%, and the material properties such as Vickers hardness, fracture toughness, and three-point bending strength reached ASTM F2094-2018a Class I materials Standard, the accuracy level reaches GB/T308.2G3 standard, and the proportion of white pit and snowflake defects is less than 0.5%. The density of the silicon nitride ceramic microspheres prepared in Comparative Example 1 reached 99.53%, the hardness only reached the ASTM F2094-2018a Class II material standard, the fracture toughness and three-point bending strength reached the Class I material standard, and the precision grade reached GB/T308.2 G10 grade standard, white spots and snowflake ratios are 32% and 18% respectively; the density of silicon nitride ceramic microspheres prepared in Comparative Example 2 reaches 99.41%, the hardness only reaches the ASTM F2094-2018a II material standard, and the fracture toughness and three The point bending strength reaches the material standard of Class I, the precision grade reaches the standard of GB/T308.2 G10, the proportion of white spots and snowflakes is 35% and 21% respectively; the density of silicon nitride ceramic microspheres prepared in Comparative Example 3 only reaches 95.11 %, the hardness is lower than the ASTM F2094-2018a grade III material standard, the fracture toughness reaches the II grade material standard, the three-point bending strength reaches the III grade material standard, the precision grade reaches the GB/T308.2 G20 standard, and the proportion of white spots and snowflakes are respectively The density of the silicon nitride ceramic microspheres prepared in Comparative Example 4 reached 96.32%, the hardness and fracture toughness reached the ASTM F2094-2018a Class II material standard, the three-point bending strength reached the Class III material standard, and the precision grade reached GB/T308.2 G20 standard, white spots and snowflake ratios are 30% and 10% respectively. Explain that the present invention solves the problem of silicon nitride ceramic microspheres by adopting a sintering method combining atmospheric pressure sintering and hot isostatic pressing sintering, adopting larger-sized silicon nitride ceramic green balls and adopting multilayer sidewall crucibles for sintering. There are defects such as pores, abnormally large grains, surface pits and snowflakes, and the high-precision preparation of silicon nitride ceramic microspheres is realized.
图2为对比例1制备的其中一个氮化硅微球的照片，从图2中可以看出氮化硅微球表面出现白坑。图3为对比例1制备的其中一个氮化硅微球的扫描电镜图，可以看到有异常大晶粒出现。FIG. 2 is a photo of one of the silicon nitride microspheres prepared in Comparative Example 1. It can be seen from FIG. 2 that white pits appear on the surface of the silicon nitride microspheres. FIG. 3 is a scanning electron microscope image of one of the silicon nitride microspheres prepared in Comparative Example 1. It can be seen that abnormally large grains appear.
以上所述仅是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (21)

  1. 一种高精度氮化硅陶瓷微球的制备方法，其特征在于，包括以下步骤：A method for preparing high-precision silicon nitride ceramic microspheres, comprising the following steps:
    将氮化硅粉、烧结助剂和分散液进行球磨混合，得到混合料液；Ball milling and mixing the silicon nitride powder, sintering aid and dispersion liquid to obtain a mixed material liquid;
    将所述混合料液进行喷雾造粒，得到造粒粉；Spraying and granulating the mixed material liquid to obtain granulated powder;
    将所述造粒粉压制成型，得到压制氮化硅陶瓷微球素坯；Compressing the granulated powder to obtain a pressed silicon nitride ceramic microsphere green body;
    将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入坩埚中依次进行气氛压力烧结和热等静压烧结，得到氮化硅毛坯球；所述较大尺寸氮化硅陶瓷素坯球的直径为压制氮化硅陶瓷微球素坯的直径的5～50倍；所述坩埚为多层侧壁的坩埚，所述多层侧壁由外到内依次包括石墨外壁、中间壁和内壁；所述中间壁和内壁的延伸方向与坩埚外壁的延伸方向一致，所述中间壁和内壁的材质为氮化硅；相邻层侧壁之间的间隙大于较大尺寸氮化硅陶瓷素坯球的直径；Put the pressed silicon nitride ceramic microsphere green body and the silicon nitride ceramic green body ball with larger size into the crucible to carry out atmosphere pressure sintering and hot isostatic pressing sintering sequentially to obtain the silicon nitride green body ball; the larger The diameter of the silicon nitride ceramic green body is 5 to 50 times the diameter of the pressed silicon nitride ceramic microsphere green body; the crucible is a crucible with multi-layer side walls, and the multi-layer side walls are sequentially It includes graphite outer wall, middle wall and inner wall; the extension direction of the middle wall and the inner wall is consistent with the extension direction of the crucible outer wall, and the material of the middle wall and the inner wall is silicon nitride; the gap between the side walls of adjacent layers is larger than that of the crucible The diameter of the large-size silicon nitride ceramic green ball;
    将所述氮化硅毛坯球进行磨削加工，得到高精度氮化硅陶瓷微球。Grinding the silicon nitride rough balls to obtain high-precision silicon nitride ceramic microspheres.
  2. 根据权利要求1所述的制备方法，其特征在于，所述较大尺寸氮化硅陶瓷素坯球的直径为20～35mm；所述压制氮化硅陶瓷微球素坯的直径为0.8～4mm。The preparation method according to claim 1, characterized in that, the diameter of the larger-sized silicon nitride ceramic green body is 20-35 mm; the diameter of the pressed silicon nitride ceramic microsphere green body is 0.8-4 mm .
  3. 根据权利要求1或2所述的制备方法，其特征在于，所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球的质量比为1：(1～3)。The preparation method according to claim 1 or 2, characterized in that the mass ratio of the pressed silicon nitride ceramic microsphere green body to the larger-sized silicon nitride ceramic green body ball is 1: (1-3).
  4. 根据权利要求1所述的制备方法，其特征在于，所述气氛压力烧结的温度为1700～1800℃，保温时间为1～3h，所述气氛压力烧结在氮气保护下进行。The preparation method according to claim 1, characterized in that the temperature of the atmosphere pressure sintering is 1700-1800° C., the holding time is 1-3 hours, and the atmosphere pressure sintering is carried out under the protection of nitrogen.
  5. 根据权利要求4所述的制备方法，其特征在于，自室温升温至所述气氛压力烧结的温度，升温速率为5～20℃/min。The preparation method according to claim 4, characterized in that, the temperature is raised from room temperature to the temperature of the atmospheric pressure sintering at a rate of 5-20° C./min.
  6. 根据权利要求4或5所述的制备方法，其特征在于，所述气氛压力烧结在常压下进行。The preparation method according to claim 4 or 5, characterized in that the atmosphere pressure sintering is carried out under normal pressure.
  7. 根据权利要求1所述的制备方法，其特征在于，所述热等静压烧结的温度为1800～1850℃，保温时间为0.5～1h，所述热等静压烧结在氮气保 护下进行，所述热等静压烧结时氮气的压力为200～210MPa。The preparation method according to claim 1, characterized in that the temperature of the hot isostatic pressing sintering is 1800-1850°C, the holding time is 0.5-1h, and the hot isostatic pressing is carried out under the protection of nitrogen. The nitrogen pressure during the hot isostatic pressing sintering is 200-210 MPa.
  8. 根据权利要求7所述的制备方法，其特征在于，升温至所述热等静压烧结的温度的升温速率为5～20℃/min。The preparation method according to claim 7, characterized in that the heating rate to the hot isostatic pressing sintering temperature is 5-20° C./min.
  9. 根据权利要求1所述的制备方法，其特征在于，所述烧结助剂的质量为氮化硅粉和烧结助剂总质量的3～5％。The preparation method according to claim 1, characterized in that the mass of the sintering aid is 3-5% of the total mass of the silicon nitride powder and the sintering aid.
  10. 根据权利要求1或9所述的制备方法，其特征在于，所述烧结助剂包括氧化铝、氧化镧、氧化钕、氧化镱、氧化铒和氧化钐中的一种或多种。The preparation method according to claim 1 or 9, characterized in that the sintering aid comprises one or more of alumina, lanthanum oxide, neodymium oxide, ytterbium oxide, erbium oxide and samarium oxide.
  11. 根据权利要求10所述的制备方法，其特征在于，以相对于氮化硅粉和烧结助剂的总质量百分比计，所述烧结助剂为氧化铝3％+氧化镧2％、氧化铝2％+氧化镥1％、或氧化铝2％+氧化铒2％。The preparation method according to claim 10, characterized in that, in terms of the total mass percentage relative to the silicon nitride powder and the sintering aid, the sintering aid is 3% alumina + 2% lanthanum oxide, 2% alumina %+lutetium oxide 1%, or alumina 2%+erbium oxide 2%.
  12. 根据权利要求1所述的制备方法，其特征在于，所述装入坩埚中为将所述压制氮化硅陶瓷微球素坯和较大尺寸氮化硅陶瓷素坯球装入多层侧壁坩埚的层间和内壁形成的腔体中。The preparation method according to claim 1, wherein the loading into the crucible is to pack the pressed silicon nitride ceramic microsphere green body and larger-sized silicon nitride ceramic green body ball into the multi-layer side wall In the cavity formed by the interlayer and inner wall of the crucible.
  13. 根据权利要求1或9所述的制备方法，其特征在于，所述分散液为无水乙醇。The preparation method according to claim 1 or 9, characterized in that the dispersion liquid is absolute ethanol.
  14. 根据权利要求13所述的制备方法，其特征在于，所述分散液的质量与氮化硅粉和烧结助剂的总质量之比为(3～4)：1。The preparation method according to claim 13, characterized in that the ratio of the mass of the dispersion liquid to the total mass of the silicon nitride powder and the sintering aid is (3-4):1.
  15. 根据权利要求1所述的制备方法，其特征在于，所述造粒粉的粒径为50～100μm。The preparation method according to claim 1, characterized in that the particle size of the granulated powder is 50-100 μm.
  16. 根据权利要求1或2所述的制备方法，其特征在于，所述内壁的厚度为2～4mm，内壁形成的同心圆的内径为90～100mm；所述中间壁的厚度为3～5mm，中间壁形成的同心圆的内径为180～200mm；所述石墨外壁的厚度为8～10mm，形成的同心圆的内径为300～320mm。The preparation method according to claim 1 or 2, characterized in that, the thickness of the inner wall is 2-4 mm, and the inner diameter of the concentric circle formed by the inner wall is 90-100 mm; the thickness of the middle wall is 3-5 mm, and the middle wall The inner diameter of the concentric circle formed by the wall is 180-200mm; the thickness of the graphite outer wall is 8-10mm, and the inner diameter of the formed concentric circle is 300-320mm.
  17. 根据权利要求1或16所述的制备方法，其特征在于，所述坩埚各个侧壁的高度相同，高度为15～17mm。The preparation method according to claim 1 or 16, characterized in that, the height of each side wall of the crucible is the same, and the height is 15-17 mm.
  18. 根据权利要求1所述的制备方法，其特征在于，所述高精度氮化硅陶瓷微球的尺寸为0.4～1mm。The preparation method according to claim 1, characterized in that the size of the high-precision silicon nitride ceramic microspheres is 0.4-1 mm.
  19. 权利要求1～18任一项所述制备方法制备得到的高精度氮化硅陶 瓷微球，其特征在于，所述高精度氮化硅陶瓷微球的表面粗糙度Ra满足：0.006μm≤Ra≤0.008μm，球直径变动量V Dw满足：0.03μm≤V Dw≤0.08μm，球形误差△S ph满足：0.03μm≤△S ph≤0.08μm。 The high-precision silicon nitride ceramic microspheres prepared by the preparation method according to any one of claims 1 to 18 are characterized in that the surface roughness Ra of the high-precision silicon nitride ceramic microspheres satisfies: 0.006μm≤Ra≤ 0.008μm, ball diameter variation V Dw satisfies: 0.03μm≤V Dw ≤0.08μm, spherical error △S ph satisfies: 0.03μm≤△S ph ≤0.08μm.
  20. 根据权利要求19所述的高精度氮化硅陶瓷微球，其特征在于，所述高精度氮化硅陶瓷微球维氏硬度HV10最高达到1480kg/mm 2，断裂韧性最高达到8MPa·m 1/2。 The high-precision silicon nitride ceramic microsphere according to claim 19, characterized in that the Vickers hardness HV10 of the high-precision silicon nitride ceramic microsphere is up to 1480kg/mm 2 , and the fracture toughness is up to 8MPa·m 1/ 2 .
  21. 权利要求19或20所述高精度氮化硅陶瓷微球在牙钻轴承中的应用。The application of the high-precision silicon nitride ceramic microspheres in claim 19 or 20 in dental drill bearings.
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CN113800919B (en) * 2021-10-26 2023-01-03 中材高新氮化物陶瓷有限公司 High-precision silicon nitride ceramic microsphere and preparation method and application thereof
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2221922A (en) * 1988-07-27 1990-02-21 Ngk Spark Plug Co Sintered silicon nitride-based materials suitable as roller bearing material, and method for producing the same
JP2000072552A (en) * 1998-08-31 2000-03-07 Kyocera Corp Silicon nitride heat radiation member and its production
WO2013160236A1 (en) * 2012-04-24 2013-10-31 Saint-Gobain Ceramic Materials A. S. Silicon nitride containing crucible and a method of producing the silicon nitride containing crucible
CN209508391U (en) * 2018-12-29 2019-10-18 广东阿格蕾雅光电材料有限公司 A kind of bilayer evaporated receptacles
CN113800919A (en) * 2021-10-26 2021-12-17 中材高新氮化物陶瓷有限公司 High-precision silicon nitride ceramic microsphere and preparation method and application thereof

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5069663B2 (en) * 2008-10-31 2012-11-07 ジャパンスーパークォーツ株式会社 Quartz glass crucible with multilayer structure
JP5729519B2 (en) * 2012-03-26 2015-06-03 日立金属株式会社 Sintered silicon nitride substrate and manufacturing method thereof
JP2016078197A (en) * 2014-10-21 2016-05-16 Ntn株式会社 Silicon nitride spheroid, manufacturing method of silicon nitride spheroid, and inspection method of silicon nitride spheroid
CN107285772A (en) * 2016-04-05 2017-10-24 新特能源股份有限公司 The production method and α phase silicon nitrides of a kind of α phase silicon nitrides
CN111548163B (en) * 2020-05-18 2022-07-15 北京中材人工晶体研究院有限公司 Method for preparing silicon nitride ceramic ball for large-size wind power generation
CN113135762B (en) * 2021-05-13 2022-03-08 中材高新氮化物陶瓷有限公司 Large-size silicon nitride ceramic ball and preparation method thereof
CN113185302B (en) * 2021-06-10 2022-08-09 灵石鸿润和新材料有限公司 Large-size silicon nitride ceramic ball for wind power generation and preparation method and application thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2221922A (en) * 1988-07-27 1990-02-21 Ngk Spark Plug Co Sintered silicon nitride-based materials suitable as roller bearing material, and method for producing the same
JP2000072552A (en) * 1998-08-31 2000-03-07 Kyocera Corp Silicon nitride heat radiation member and its production
WO2013160236A1 (en) * 2012-04-24 2013-10-31 Saint-Gobain Ceramic Materials A. S. Silicon nitride containing crucible and a method of producing the silicon nitride containing crucible
CN209508391U (en) * 2018-12-29 2019-10-18 广东阿格蕾雅光电材料有限公司 A kind of bilayer evaporated receptacles
CN113800919A (en) * 2021-10-26 2021-12-17 中材高新氮化物陶瓷有限公司 High-precision silicon nitride ceramic microsphere and preparation method and application thereof

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