Fused quartz hemispherical resonator and method of manufacture

Abstract

The present application belongs to the technical field of fused quartz hemispherical resonator processing and manufacturing, and discloses a fused quartz hemispherical resonator and a preparation method. The quartz glass rod material is annealed by twice annealing process, the magnetic fluid polishing adopts a magnetic fluid polishing device, the magnetic powder adopts oil-based liquid as carrier and adds cerium oxide; the safety protection of the fused quartz hemispherical resonator is realized in the chemical polishing and cleaning process by using a tool; the surface residues of the fused quartz hemispherical resonator are removed by multiple cleaning and ultrasonic cleaning. The fused quartz hemispherical resonator prepared by the present application has the advantages of low surface damage layer, small stress, high quality factor and the like, solves the problems existing in the current fused quartz hemispherical resonator processing process, improves the fused quartz hemispherical resonator processing efficiency and enhances the performance index of the fused quartz hemispherical resonator, and realizes the engineering application of the fused quartz hemispherical resonator.

Description

Technical Field

[0001] The invention belongs to the technical field of fused quartz hemispherical resonator processing and manufacturing, and in particular relates to a fused quartz hemispherical resonator and a preparation method thereof. Background Art

[0002] Currently, the fused silica hemispherical resonator (HSR) is the most promising solid-state wave gyroscope in the aerospace industry. The HSR is made of a thin-walled, ultra-precision spherical cup-shaped component made of fused silica glass. The HSR's operation requires continuous vibration at a specific frequency, which creates a four-antinode shape around the edge of the spherical shell. Therefore, it is the core and sensitive component of the HSR. Its performance is directly influenced by parameters such as dimensional accuracy, surface roughness, quality factor, and frequency resolution. The dimensional accuracy of the HSR is primarily influenced by the accuracy of the machine tool spindle, tooling, and machining process. The surface roughness, surface stress level, and degree of crack damage are related to the polishing method. Given a given structural dimension, the HSR's quality factor, damping nonuniformity, frequency resolution, and mode deviation are related to the HSR's structural dimension accuracy, surface crack layer thickness, and internal stress level.

[0003] The current fabrication process for fused silica hemispherical resonators faces the following major challenges: Relying solely on ultra-precision grinding machines makes it difficult to balance the geometric accuracy and surface roughness of the spherical surface. The polishing method and timing also affect the uniformity of the polish and the removal of the crack layer, limiting the efficiency and performance of fused silica hemispherical resonators. Therefore, a new fabrication method for fused silica hemispherical resonators is urgently needed. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a fused quartz hemispherical resonator and a preparation method thereof.

[0005] The present invention is achieved by providing a method for preparing a fused quartz hemispherical resonator. The method comprises annealing a quartz glass rod in two annealing steps, using a magnetic fluid polishing device for magnetic fluid polishing, and using an oil-based liquid as a carrier for magnetic powder with cerium oxide added. A tool is used to achieve chemical polishing and to ensure safety protection of the fused quartz hemispherical resonator during cleaning. Multiple cleaning steps and ultrasonic cleaning are used to remove residues on the surface of the fused quartz hemispherical resonator.

[0006] Furthermore, the preparation method of the fused silica hemispherical resonator comprises the following steps:

[0007] Step 1: Rough-processing the fused quartz glass rod to a process size, and placing the quartz glass rod in a vacuum annealing furnace for a primary annealing treatment;

[0008] Step 2: Using a precision spherical surface processing grinding head to shape the outer surface of the fused quartz hemispherical resonator; performing coarse grinding and semi-fine grinding on the outer surface of the fused quartz hemispherical resonator;

[0009] Step 3: polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; soaking and cleaning the fused quartz hemispherical resonator with a cleaning solution, and then rinsing the fused quartz hemispherical resonator with deionized water;

[0010] Step 4: using a precision spherical surface processing grinding head to shape the inner surface of the fused quartz hemispherical resonator; performing coarse grinding and semi-fine grinding on the inner surface of the fused quartz hemispherical resonator;

[0011] Step 5: polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; and cleaning the fused quartz hemispherical resonator using deionized water;

[0012] Step 6: placing the quartz glass rod into a vacuum annealing furnace for secondary annealing, and performing a magnetic fluid polishing treatment on the fused quartz hemispherical resonator after the secondary annealing;

[0013] Step 7: immersing the fused quartz hemispherical resonator in a chemical polishing solution for chemical polishing; and cleaning the fused quartz hemispherical resonator with deionized water;

[0014] Step eight, polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; soaking and cleaning the fused quartz hemispherical resonator with a cleaning solution, and then rinsing the fused quartz hemispherical resonator with deionized water.

[0015] Furthermore, the diameter of the quartz glass rod is larger than the maximum process diameter of the fused quartz hemispherical resonator to be prepared, and the length of the quartz rod meets the process processing and clamping requirements;

[0016] The primary annealing and the secondary annealing both include a temperature rising stage, a temperature keeping stage and a temperature falling stage.

[0017] In the heating stage, the temperature in the vacuum furnace is raised from room temperature to 860-880°C at a heating rate of 10-15°C / min; the furnace temperature is raised from 860-880°C to 1030-1050°C at a heating rate of 5-10°C / min.

[0018] During the insulation stage, the temperature in the vacuum furnace is maintained at 1030-1050° C. for 480-540 minutes.

[0019] In the cooling stage, the temperature in the vacuum furnace is reduced from 1030-1050° C. to 800-820° C. at a cooling rate of 2° C. / min, and then to 350-380° C. at a cooling rate of 3-5° C. / min, and then naturally cooled to room temperature.

[0020] Furthermore, in the outer surface molding and inner surface molding steps of the fused quartz hemispherical resonator, the method parameters α of the fused quartz hemispherical resonator processing, β of the grinding head angular velocity, γ of the swing angle amplitude, and the elastic loading force F method parameter combination sequence are: α=31r / min, β=29r / min, γ=±41°, rough grinding F=3 / 5N, semi-fine grinding F=0.8 / 1N.

[0021] Method tests were carried out on the size of the grinding head cylinder mouth, the material and abrasive particles of the grinding agent, and the fixture tooling to obtain the proportional coefficient between the size d of the grinding head cylinder mouth and the spherical shell diameter Φ, d = (0.7~0.85) × Φmm; as a preferred method, the optimal proportional coefficient between the size d of the magnetic head cylinder mouth and the spherical shell diameter Φ is d = 0.8 × Φmm.

[0022] Furthermore, the cleaning liquid is a mixed liquid of gasoline, ether, acetone and ethanol. The fused quartz hemispherical resonator is immersed in the cleaning liquid for 2 to 3 hours and rinsed with deionized water for 2 to 5 minutes.

[0023] The chemical polishing liquid includes hydrofluoric acid, sulfuric acid, deionized water or a mixture of hydrofluoric acid, hydrochloric acid and deionized water. The temperature of the chemical polishing liquid is 35 to 60° C. The thickness of the surface of the fused quartz hemispherical resonator is etched and removed by 2 to 5 μm. After chemical polishing, a neutralizing liquid is used to neutralize the fused quartz hemispherical resonator parts.

[0024] Furthermore, the fused silica hemispherical resonator is polished by magnetic fluid using a dedicated magnetic fluid polishing device, the magnetic powder uses an oil-based liquid as a carrier, and cerium oxide is added as a polishing component.

[0025] A magnetic fluid polishing device is used to perform fine grinding and polishing on the inner and outer surfaces of the fused quartz hemispherical resonator using a spherical surface development principle; and a water-based magnetic fluid with a ratio of 10 to 15:1 is selected for the magnetic fluid polishing.

[0026] Furthermore, a placement tool for the same material is provided in the vacuum furnace, and the fused quartz hemispherical resonator is vertically placed on the placement tool.

[0027] Select the grinding machine particle size according to the precision. For coarse grinding, select W40~W20; for semi-fine grinding, select W10~W3.5.

[0028] Furthermore, the polishing includes: placing the fused quartz hemispherical resonator into a special chemical polishing tool for pretreatment; purging the fused quartz hemispherical resonator with high-purity nitrogen, then immersing it in deionized water, and ultrasonically cleaning it for 10 to 15 minutes; heating the chemical polishing liquid to 35 to 60° C. and keeping it warm; placing the pretreated fused quartz hemispherical resonator together with the tool into the chemical polishing liquid for chemical polishing treatment, with a single polishing time of 6 to 10 minutes; and the number of polishing times is determined based on the quality factor value of the fused quartz hemispherical resonator after polishing.

[0029] Preferably, the ultrasonic cleaning time is 15 minutes; the chemical polishing liquid is heated to 50° C. and kept warm; and the single polishing time is 10 minutes.

[0030] Furthermore, the cleaning includes: placing the fused quartz hemispherical resonator into a special cleaning tool for pre-cleaning; immersing it in a hydrochloric acid solution for ultrasonic cleaning for 15 to 20 minutes, taking it out and cleaning it with deionized water for 2 to 5 minutes, and then blowing it dry with high-purity nitrogen; using a microscope to detect whether there is any residue on the surface of the fused quartz hemispherical resonator, and repeating the pre-cleaning 2 to 3 times depending on the residue; after pre-cleaning, placing the fused quartz hemispherical resonator in a cleaning solution and soaking it for 2 to 3 hours, rinsing it with deionized water for 2 to 5 minutes, and then blowing it dry with high-purity nitrogen.

[0031] Preferably, the ultrasonic cleaning time is 20 minutes, the surface is cleaned with deionized water for 5 minutes, and the pre-cleaning is repeated 3 times depending on the residual situation; the surface is soaked in the cleaning solution for 3 hours, and rinsed with deionized water for 5 minutes.

[0032] Another object of the present invention is to provide a fused silica hemispherical resonator prepared by implementing the preparation method of the fused silica hemispherical resonator.

[0033] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0034] The fused silica hemispherical resonator prepared in the present invention is a core component of a quartz hemispherical resonator gyroscope. Its dimensional accuracy, surface quality, and quality factor are crucial for ensuring the precision of the gyroscope. The fused silica hemispherical resonator prepared in the present invention, using the aforementioned preparation method and process, exhibits advantages such as low surface damage, low stress, and a high quality factor.

[0035] The preparation method of the fused quartz hemispherical resonator provided by the application adjusts the timing of the two annealing processes, mainly reduces the mechanical stress generated in the rapid volume reduction process during the processing of the fused quartz hemispherical resonator.

[0036] The application uses special fixtures to realize the safety protection of the fused quartz hemispherical resonator in the chemical polishing and cleaning processes, and uses multiple cleaning and ultrasonic cleaning to remove the residues on the surface of the fused quartz hemispherical resonator.

[0037] The application solves the problems existing in the processing of the fused quartz hemispherical resonator, improves the processing efficiency of the fused quartz hemispherical resonator, improves the performance indicators of the fused quartz hemispherical resonator, and realizes the engineering application of the fused quartz hemispherical resonator.

[0038] The fused quartz hemispherical resonator prepared by the application has the advantages of low surface damage layer, small stress, high quality factor, etc.

[0039] The technical scheme of the application solves the technical problems that people have been eager to solve but have failed to successfully solve: the application designs special grinding heads and magnetic fluid polishing fixtures for the polishing of the fillet of the inner spherical surface and the root of the inner support rod of the hemispherical fused quartz hemispherical resonator and the polishing of the lip plane of the hemispherical fused quartz hemispherical resonator, meets the processing quality of the fillet surface of the inner spherical surface and the root of the inner support rod and the lip plane, and solves the processing quality problems of the fillet of the inner spherical surface and the root of the inner support rod and the lip plane.

[0040] The technical scheme of the application overcomes the technical bias: the efficiency distribution problem of grinding and magnetic fluid polishing is comprehensively solved, the crack layer damage of the fillet of the inner spherical surface and the root of the inner support rod is reduced through the multiple polishing processes such as magnetic fluid polishing and chemical polishing after grinding, and the processing efficiency of the single use of the magnetic fluid polishing process is improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical scheme of the embodiments of the application, the drawings needed in the embodiments of the application will be briefly introduced as follows: obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0042] Figure 1This is a flow chart of a method for preparing a fused silica hemispherical resonator provided by an embodiment of the present invention;

[0043] Figure 2 It is a schematic diagram of the principle of the method for preparing the fused silica hemispherical resonator provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] In view of the problems existing in the prior art, the present invention provides a fused silica hemispherical resonator and a preparation method thereof. The present invention is described in detail below with reference to the accompanying drawings.

[0046] Example 1

[0047] like Figure 1 As shown, the preparation method of the fused silica hemispherical resonator (quartz resonator or resonator) provided in the embodiment of the present invention includes the following steps:

[0048] S101, rough-processing the fused quartz glass rod to a process size, and placing the quartz glass rod in a vacuum annealing furnace for a primary annealing treatment;

[0049] S102, using a precision spherical surface processing grinding head to shape the outer surface of the fused quartz hemispherical resonator; performing coarse grinding and semi-fine grinding on the outer surface of the fused quartz hemispherical resonator;

[0050] S103, polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; soaking and cleaning the fused quartz hemispherical resonator with a cleaning solution, and then rinsing the fused quartz hemispherical resonator with deionized water;

[0051] S104, using a precision spherical surface processing grinding head to shape the inner surface of the fused quartz hemispherical resonator; performing coarse grinding and semi-fine grinding on the inner surface of the fused quartz hemispherical resonator;

[0052] S105, polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; cleaning the fused quartz hemispherical resonator using deionized water;

[0053] S106, placing the quartz glass rod in a vacuum annealing furnace for secondary annealing, and performing a magnetic fluid polishing process on the fused quartz hemispherical resonator after the secondary annealing;

[0054] S107, immersing the fused quartz hemispherical resonator in a chemical polishing solution for chemical polishing; and cleaning the fused quartz hemispherical resonator with deionized water;

[0055] S108, polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; soaking and cleaning the fused quartz hemispherical resonator using a cleaning liquid, and then rinsing the fused quartz hemispherical resonator using deionized water.

[0056] The primary annealing and secondary annealing provided in the embodiment of the present invention both include a heating stage, a heat preservation stage, and a cooling stage. The mechanical stress in the fused silica hemispherical resonator processing is eliminated through the two annealing processes before and after the rapid de-massing process.

[0057] During the heating stage, the temperature in the vacuum furnace rises from room temperature to (860-880)°C at a heating rate of (10-15)°C / min, and the furnace temperature rises from (860-880)°C to (1050-1030)°C at a heating rate of (5-10)°C / min.

[0058] During the insulation stage, the temperature in the vacuum furnace is maintained at (1050-1030)°C for (480-540) minutes.

[0059] During the cooling stage, the temperature in the vacuum furnace was reduced from (1050-1030)°C to (820-800)°C at a cooling rate of 2°C / min, and then to (380-350)°C at a cooling rate of (3-5)°C / min, and finally cooled naturally to room temperature.

[0060] In the outer surface molding and inner surface molding steps of the fused silica hemispherical resonator, the embodiment of the present invention preferably uses a method parameter combination sequence of the fused silica hemispherical resonator processing method parameters α spindle angular velocity, β grinding head angular velocity, γ swing angular amplitude, and elastic loading force F; the method parameter combination is: α = 31 r / min, β = 29 r / min, γ = ± 41°, rough grinding F = 5 N, semi-fine grinding F = 1 N.

[0061] According to the preparation method of the fused quartz hemispherical resonator provided in an embodiment of the present invention, in order to ensure ultra-precision machining accuracy, special research and method tests were carried out on the size of the grinding head cylinder mouth, the material and abrasive particles of the abrasive, and the fixture tooling, and the proportional coefficient of the grinding head cylinder mouth size d and the spherical shell diameter Φ was obtained, d = (0.7~0.85)×Φmm, the smaller value was taken for coarse grinding, and 0.8 was taken for fine grinding.

[0062] The cleaning liquid provided in the embodiment of the present invention is a mixed liquid of gasoline, ether, acetone, and ethanol. The fused quartz hemispherical resonator is immersed in the cleaning liquid for (2-3) hours and then rinsed with deionized water for (2-5) minutes.

[0063] The chemical polishing solution provided in the embodiments of the present invention includes hydrofluoric acid, sulfuric acid, deionized water, or a mixture of hydrofluoric acid, hydrochloric acid, deionized water, etc. The temperature of the chemical polishing solution is 35 to 60 degrees Celsius. The thickness of the surface of the fused quartz hemispherical resonator is etched away to a thickness of 2 to 5 microns. After chemical polishing, the fused quartz hemispherical resonator components need to be neutralized using a separate neutralizing liquid.

[0064] In the embodiment of the present invention, the particle size of the grinder is selected according to the precision, and W40 to W20 is selected for general coarse grinding; and W10 to W3.5 is selected for semi-fine grinding.

[0065] The embodiment of the present invention adopts a magnetic fluid polishing device to perform fine grinding and polishing on the inner and outer surfaces of a fused quartz hemispherical resonator using the spherical surface development principle.

[0066] According to an embodiment of the present invention, a dedicated tool is used to achieve chemical polishing and safety protection of the fused quartz hemispherical resonator during cleaning; multiple cleaning and ultrasonic cleaning are used to remove residues on the surface of the fused quartz hemispherical resonator.

[0067] In the embodiment of the present invention, the fused quartz hemispherical resonator is placed in a special chemical polishing tool for pretreatment. The fused quartz hemispherical resonator is first purged with high-purity nitrogen, then immersed in deionized water and ultrasonically cleaned for 10 minutes to 15 minutes. The chemical polishing liquid is heated to (35 to 60)°C and kept warm. The pretreated fused quartz hemispherical resonator is placed together with the tool into the chemical polishing liquid for chemical polishing treatment, and the single polishing time is 6 minutes to 10 minutes. The number of polishing times is confirmed based on the quality factor value of the fused quartz hemispherical resonator after polishing.

[0068] In the embodiment of the present invention, the fused quartz hemispherical resonator is placed in a special cleaning tool for pre-cleaning. It is immersed in a hydrochloric acid solution and ultrasonically cleaned for 15 minutes to 20 minutes. After being removed, it is rinsed with deionized water for 2 minutes to 5 minutes and then blown dry with high-purity nitrogen. The surface of the fused quartz hemispherical resonator is inspected with a microscope to see if there is any residue; the pre-cleaning is repeated 2 to 3 times depending on the residue; after the pre-cleaning is completed, the fused quartz hemispherical resonator is immersed in the cleaning solution for (2 to 3) hours, then rinsed with deionized water for (2 to 5) minutes; and finally blown dry with high-purity nitrogen.

[0069] According to an embodiment of the present invention, through magnetic fluid polishing, the concentration of the magnetic fluid medium and the magnetic force of the magnet have a great influence on the processing. If the magnetic medium is too viscous, the magnetic force will be weakened, and finally a water-based magnetic fluid with a ratio of (15 to 10):1 is selected.

[0070] Example 2

[0071] As a preferred embodiment, Figure 2As shown, the preparation method of the fused quartz hemispherical resonator provided by the embodiment of the present application specifically comprises the following steps:

[0072] P1, bar processing: rough processing of a fused quartz glass bar to a process size; the diameter of the quartz glass bar is greater than the maximum diameter of the fused quartz hemispherical resonator to be prepared, and the length of the quartz bar meets the process clamping requirement;

[0073] P2, primary annealing: placing the quartz glass bar into a vacuum annealing furnace for annealing treatment;

[0074] P3, outer surface forming: using a precision spherical surface processing grinding head to perform forming treatment on the outer surface of the fused quartz hemispherical resonator;

[0075] P4, outer surface rough grinding: rough grinding is performed on the outer surface of the fused quartz hemispherical resonator;

[0076] P5, outer surface semi-fine grinding: semi-fine grinding is performed on the outer surface of the fused quartz hemispherical resonator;

[0077] P6, magnetic fluid polishing: magnetic fluid equipment is used to polish the outer surface of the fused quartz hemispherical resonator;

[0078] P7, cleaning: using a cleaning liquid to soak and clean the fused quartz hemispherical resonator, and then using deionized water to rinse the fused quartz hemispherical resonator;

[0079] P8, inner surface forming: using a precision spherical surface processing grinding head to perform forming treatment on the inner surface of the fused quartz hemispherical resonator;

[0080] P9, inner surface rough grinding: rough grinding is performed on the inner surface of the fused quartz hemispherical resonator;

[0081] P10, inner surface semi-fine grinding: semi-fine grinding is performed on the inner surface of the fused quartz hemispherical resonator;

[0082] P11, magnetic fluid polishing: magnetic fluid equipment is used to polish the outer surface of the fused quartz hemispherical resonator;

[0083] P12, cleaning: using deionized water to clean the fused quartz hemispherical resonator;

[0084] P13, secondary annealing: placing the quartz glass bar into a vacuum annealing furnace for annealing treatment;

[0085] P14, magnetic fluid polishing: performing magnetic fluid polishing treatment on the fused quartz hemispherical resonator after secondary annealing;

[0086] P15, chemical polishing: immersing the fused quartz hemispherical resonator in a chemical polishing liquid for chemical polishing;

[0087] P16, cleaning: using deionized water to clean the fused silica hemispherical resonator;

[0088] P17, magnetic fluid polishing: polishing the outer surface of the fused silica hemispherical resonator using a magnetic fluid device;

[0089] P18, cleaning: Use cleaning solution to soak and clean the fused quartz hemispherical resonator, and then use deionized water to rinse the fused quartz hemispherical resonator.

[0090] As a preferred embodiment, the primary annealing and the secondary annealing both include a heating stage, a holding stage, and a cooling stage; in the heating stage, the temperature in the vacuum furnace is preferably raised from room temperature to 860°C at a heating rate of 10°C / min, and then the furnace temperature is raised from 860°C to 1050°C at a heating rate of 5°C / min.

[0091] During the holding stage, the temperature in the vacuum furnace is preferably maintained at 1050° C. for 480 minutes.

[0092] In the cooling stage, the temperature in the vacuum furnace is preferably reduced from 1050°C to 800°C at a cooling rate of 2°C / min, then to 380°C at a cooling rate of 5°C / min, and finally cooled naturally to room temperature.

[0093] In the outer surface molding and inner surface molding steps of the fused quartz hemispherical resonator, the method parameters for machining the fused quartz hemispherical resonator are a spindle angular velocity α, a grinding head angular velocity β, a swing angular amplitude γ, and a method parameter combination sequence of an elastic loading force F; the method parameter combination is: α=31 r / min, β=29 r / min, γ=±41°, rough grinding F=3 N, and semi-fine grinding F=0.8 N.

[0094] In order to ensure ultra-precision machining accuracy, the embodiment of the present invention has conducted special research and method tests on the size of the grinding head cylinder mouth, the material and abrasive particles of the grinding agent, and the fixture tooling, and obtained the proportional coefficient between the size d of the grinding head cylinder mouth and the spherical shell diameter Φ, d = (0.7~0.85)×Φmm, the smaller value is taken for coarse grinding, and 0.8 is taken for semi-fine grinding.

[0095] According to the method for preparing the fused silica hemispherical resonator provided by the embodiment of the present invention, the timing of the two annealing steps is adjusted, mainly to reduce the mechanical stress generated by the rapid de-weighting process during the processing of the fused silica hemispherical resonator.

[0096] According to the method for preparing the fused silica hemispherical resonator of the embodiment of the present invention, the magnetic fluid polishing adopts a special magnetic fluid polishing equipment, the magnetic powder adopts an oil-based liquid as a carrier, and cerium oxide can be added as a polishing component to improve the polishing efficiency.

[0097] The fused quartz hemispherical resonator magnetic fluid polishing provided by the embodiment of the present application adopts a special magnetic fluid polishing device, magnetic powder adopts oil-based liquid as a carrier, and cerium oxide can be added as a polishing component, so that the polishing efficiency is greatly improved.

[0098] The embodiment of the present application provides a placing tool of the same material in the vacuum furnace, and the fused quartz hemispherical resonator is vertically placed on the placing tool.

[0099] As a preferred embodiment, the present application puts the fused quartz hemispherical resonator into a special chemical polishing tool for pretreatment. First, the fused quartz hemispherical resonator is blown with high-purity nitrogen, and then is immersed in deionized water for ultrasonic cleaning for 15 min. The chemical polishing liquid is heated to 50 DEG C and is placed in an incubator. The pretreated fused quartz hemispherical resonator is placed in the chemical polishing liquid together with the tool for chemical polishing treatment, and the single polishing time is 10 min. The polishing frequency is determined according to the quality factor value of the fused quartz hemispherical resonator after polishing.

[0100] As a preferred embodiment, the present application puts the fused quartz hemispherical resonator into a special cleaning tool for pre-cleaning. The ultrasonic cleaning is carried out by immersing in hydrochloric acid solution for 20 min, and then the fused quartz hemispherical resonator is cleaned with deionized water for 5 min and dried with high-purity nitrogen. Whether there is residue on the surface of the fused quartz hemispherical resonator is detected by a microscope. The pre-cleaning is repeated 3 times according to the residue. After the pre-cleaning, the fused quartz hemispherical resonator is immersed in the cleaning liquid for 3 h, and then is washed with deionized water for 5 min. Finally, the fused quartz hemispherical resonator is dried with high-purity nitrogen.

[0101] The embodiment of the present application specially researches and processes the size of the magnetic head cylinder port, the material and the polishing liquid of the polishing medium, and the jig tool, and obtains the best ratio coefficient of the size d of the magnetic head cylinder port and the spherical diameter Φ of the spherical shell, d = 0.8 * Φ mm.

[0102] According to the fused quartz hemispherical resonator provided by the embodiment of the present application, the surface crack layer of the fused quartz hemispherical resonator can be removed by using the preparation method as described above, and the fused quartz hemispherical resonator has high quality factor and uniform damping.

[0103] As a preferred embodiment, the present application selects a water-based magnetic fluid with a ratio of 10:1 through magnetic fluid polishing.

[0104] According to the fused quartz hemispherical resonator provided by the embodiment of the present application, the fused quartz hemispherical resonator has the advantages of low surface damage layer, small stress, high quality factor, etc. by using the preparation method and the process route as described above.

[0105] The embodiment of the present invention is described by taking the preparation of a hemispherical fused silica hemispherical resonator with an outer diameter of 21.9 mm, an inner diameter of 20.5 mm, and a support rod diameter of 5 mm as an example.

[0106] P1, rod processing: rough processing of fused silica glass rods to process size (rod length 30 mm, diameter 25 mm);

[0107] P2, primary annealing: placing the quartz glass rod in a vacuum annealing furnace for annealing;

[0108] The primary annealing process includes a heating stage, a holding stage, and a cooling stage. During the heating stage, the temperature in the vacuum furnace is raised from room temperature to (860±10)°C at a heating rate of (10±2)°C / min, and then the furnace temperature is raised from (860±10)°C to (1050±10)°C at a heating rate of (5±2)°C / min.

[0109] During the holding stage, the temperature in the vacuum furnace was maintained at (1050±10)°C for (480±30) min.

[0110] During the cooling stage, the temperature in the vacuum furnace was reduced from (1050±10)℃ to (800±10)℃ at a cooling rate of (2±0.5)℃ / min, and then to (380±10)℃ at a cooling rate of (5±2)℃ / min, and finally cooled naturally to room temperature.

[0111] P3, outer surface molding: using a precision spherical machining grinding head to mold the outer surface of the fused quartz hemispherical resonator;

[0112] P4, outer surface rough grinding: rough grinding the outer surface of the fused silica hemispherical resonator;

[0113] P5, semi-fine grinding of outer surface: semi-fine grinding of the outer surface of the fused silica hemispherical resonator;

[0114] A method parameter combination sequence of α spindle angular velocity, β grinding head angular velocity, γ swing angular amplitude, and elastic loading force F; the method parameter combination is: α=31r / min, β=29r / min, γ=±41°, rough grinding F=3N, semi-fine grinding F=0.8N.

[0115] P6, magnetic fluid polishing: polishing the outer surface of the fused silica hemispherical resonator using a magnetic fluid device, using a 10:1 water-based magnetic fluid;

[0116] P7, cleaning: soak and clean the fused quartz hemispherical resonator with a solution of acetone and 13% hydrochloric acid in a volume ratio of 1:1, and then rinse the fused quartz hemispherical resonator with 0.3 MPa deionized water for at least 5 minutes;

[0117] P8, inner surface molding: using a precision spherical machining grinding head to mold the inner surface of the fused quartz hemispherical resonator;

[0118] P9, inner surface rough grinding: rough grinding the inner surface of the fused silica hemispherical resonator;

[0119] P10, semi-fine grinding of inner surface: semi-fine grinding of the inner surface of the fused quartz hemispherical resonator;

[0120] A method parameter combination sequence of α spindle angular velocity, β grinding head angular velocity, γ swing angular amplitude, and elastic loading force F; the method parameter combination is: α=31r / min, β=29r / min, γ=±41°, rough grinding F=3N, semi-fine grinding F=0.5N.

[0121] P11, magnetic fluid polishing: polishing the outer surface of the fused silica hemispherical resonator using a magnetic fluid device;

[0122] P12, cleaning: soak and clean the fused quartz hemispherical resonator with a solution of acetone and 13% hydrochloric acid in a volume ratio of 1:1, and then rinse the fused quartz hemispherical resonator with 0.3 MPa pressure deionized water for at least 5 minutes;

[0123] P13, secondary annealing: placing the quartz glass rod in a vacuum annealing furnace for annealing;

[0124] The secondary annealing includes a heating stage, a holding stage, and a cooling stage. During the heating stage, the temperature in the vacuum furnace is increased from room temperature to (860±10)°C at a heating rate of (10±2)°C / min, and then the furnace temperature is increased from (860±10)°C to (1050±10)°C at a heating rate of (5±2)°C / min.

[0125] During the holding stage, the temperature in the vacuum furnace was maintained at (1050±10)°C for (480±30) min.

[0126] During the cooling stage, the temperature in the vacuum furnace was reduced from (1050±10)℃ to (800±10)℃ at a cooling rate of (2±0.5)℃ / min, and then to (380±10)℃ at a cooling rate of (5±2)℃ / min, and finally cooled naturally to room temperature.

[0127] P14, magnetic fluid polishing: subjecting the fused silica hemispherical resonator after secondary annealing to magnetic fluid polishing;

[0128] P15, Chemical Polishing: Immerse the fused quartz hemispherical resonator in a chemical polishing solution for chemical polishing. Heat the solution to 50°C and keep it warm. The polishing solution is an acidic cleaning solution consisting of hydrofluoric acid and ultrapure water in a ratio of 1:10. Ultrasonic cleaning and bubbling cleaning (120-160 kHz) are used. The single polishing time is 5 minutes.

[0129] P16, Cleaning: Use a solution of acetone and 13% hydrochloric acid in a volume ratio of 1:1 to soak and clean the fused quartz hemispherical resonator, and then use 0.3 MPa pressure deionized water to rinse the fused quartz hemispherical resonator for not less than 5 minutes.

[0130] P17, magnetic fluid polishing: polish the outer surface of the fused silica hemispherical resonator using a magnetic fluid device, using a 10:1 water-based magnetic fluid;

[0131] P18, Cleaning: Use a solution of acetone and 13% hydrochloric acid in a volume ratio of 1:1 to soak and clean the fused quartz hemispherical resonator, and then use 0.3 MPa pressure deionized water to rinse the fused quartz hemispherical resonator for not less than 5 minutes.

[0132] Taking the preparation of a hemispherical fused silica resonator with an outer diameter of 21.9mm, an inner diameter of 20.5mm, and a support rod diameter of 5mm as an example, the morphological accuracy and surface quality of the spherical surface of the fused silica hemispherical resonator are effectively guaranteed through grinding and multiple chemical polishing processes. At the same time, through magnetic fluid processing, the coaxiality of the fused silica hemispherical resonator shell and the support rod is controlled to be better than 0.5, and the radial concentricity of the sphere center of the inner and outer surfaces of the shell is better than 0.5μm. The transition radius R runout between the inner surface of the shell and the support rod is better than 2μm, the flatness of the shell lip is better than 1μm, and the perpendicularity of the shell lip plane to the support rod axis is better than 1μm.

[0133] Taking the preparation of a hemispherical fused silica hemispherical resonator with an outer diameter of 21.9 mm, an inner diameter of 20.5 mm, and a support rod diameter of 5 mm as an example, the dimensional accuracy and behavioral accuracy of the fused silica hemispherical resonator are prepared through application examples, and the quality factor of the fused silica hemispherical resonator can reach 1.3×10 7 .

[0134] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a fused silica hemispherical resonator, characterized in that: The preparation method of the fused silica hemispherical resonator adopts two annealing processes to anneal the quartz glass rod, adopts a magnetic fluid polishing device for magnetic fluid polishing, adopts an oil-based liquid as a carrier for magnetic powder and adds cerium oxide, uses a tool to achieve chemical polishing and safety protection of the fused silica hemispherical resonator during the cleaning process, and adopts multiple cleaning and ultrasonic cleaning to remove residues on the surface of the fused silica hemispherical resonator. The preparation method of the fused silica hemispherical resonator comprises the following steps: Step 1: Rough processing is performed on the fused quartz glass rod, and the quartz glass rod is placed in a vacuum annealing furnace for a primary annealing treatment; Step 2: Use a precision spherical surface processing grinding head to shape the outer surface of the fused quartz hemispherical resonator; perform rough grinding and semi-fine grinding on the outer surface of the fused quartz hemispherical resonator; Step 3: polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; soaking and cleaning the fused quartz hemispherical resonator with a cleaning solution, and then rinsing the fused quartz hemispherical resonator with deionized water; Step 4: using a precision spherical surface processing grinding head to shape the inner surface of the fused quartz hemispherical resonator; performing rough grinding and semi-fine grinding on the inner surface of the fused quartz hemispherical resonator; Step 5: polishing the outer surface of the fused quartz hemispherical resonator with a magnetic fluid device; cleaning the fused quartz hemispherical resonator with deionized water; Step 6: Place the quartz glass rod in a vacuum annealing furnace for secondary annealing, and perform magnetic fluid polishing on the fused quartz hemispherical resonator after the secondary annealing; Step 7: immerse the fused quartz hemispherical resonator in a chemical polishing solution for chemical polishing; and clean the fused quartz hemispherical resonator with deionized water; Step eight, polishing the outer surface of the fused quartz hemispherical resonator using a magnetic fluid device; soaking and cleaning the fused quartz hemispherical resonator with a cleaning solution, and then rinsing the fused quartz hemispherical resonator with deionized water; The diameter of the quartz glass rod is larger than the maximum process diameter of the fused quartz hemispherical resonator to be prepared; The primary annealing and the secondary annealing both include a heating stage, a heat preservation stage and a cooling stage; In the heating stage, the temperature in the vacuum annealing furnace is increased from room temperature to 860°C~880°C at a heating rate of 10°C / min~15°C / min; the furnace temperature is increased from 860°C~880°C to 1030°C~1050°C at a heating rate of 5°C / min~10°C / min; During the holding stage, the temperature in the vacuum annealing furnace is maintained at 1030° C. to 1050° C. for 480 min to 540 min. In the cooling stage, the temperature in the vacuum annealing furnace is reduced from 1030°C to 1050°C at a cooling rate of 2°C / min to 800°C to 820°C, and then to 350°C to 380°C at a cooling rate of 3°C / min to 5°C / min, and then naturally cooled to room temperature; The fused silica hemispherical resonator is polished by magnetic fluid using a dedicated magnetic fluid polishing device, the magnetic powder uses an oil-based liquid as a carrier, and cerium oxide is added as a polishing component; A magnetic fluid polishing device is used to perform fine grinding and polishing on the inner and outer surfaces of the fused quartz hemispherical resonator using a spherical surface development principle; and a water-based magnetic fluid with a ratio of 10 to 15:1 is selected for magnetic fluid polishing.

2. The method for preparing a fused silica hemispherical resonator according to claim 1, wherein: In the outer surface molding and inner surface molding steps of the fused quartz hemispherical resonator, the method parameters for the fused quartz hemispherical resonator machining are a spindle angular velocity α, a grinding head angular velocity β, a swing angular amplitude γ, and a method parameter combination sequence of an elastic loading force F; the method parameter combination is: α=31 r / min, β=29 r / min, γ=±41°, rough grinding F=3 / 5N, semi-fine grinding F=0.8 / 1N; Method tests were conducted on the size of the grinding head cylinder mouth, the material and abrasive particles of the abrasive, and the fixture tooling, and the proportional coefficient between the size d of the grinding head cylinder mouth and the spherical shell diameter Φ was obtained, d=(0.7~0.85)×Φmm.

3. The method for preparing a fused silica hemispherical resonator according to claim 1, wherein: The cleaning liquid is a mixed liquid of gasoline, ether, acetone and ethanol. The fused quartz hemispherical resonator is immersed in the cleaning liquid for 2 to 3 hours and rinsed with deionized water for 2 to 5 minutes. The chemical polishing liquid includes hydrofluoric acid, sulfuric acid, deionized water or a mixture of hydrofluoric acid, hydrochloric acid and deionized water. The temperature of the chemical polishing liquid is 35-60° C. The surface of the fused quartz hemispherical resonator is etched and removed to a thickness of 2-5 μm. After chemical polishing, the fused quartz hemispherical resonator parts are neutralized using a neutralizing liquid.

4. The method for preparing a fused silica hemispherical resonator according to claim 1, wherein: The vacuum annealing furnace is provided with a placement tool for the same material, and the fused quartz hemispherical resonator is vertically placed on the placement tool; For coarse grinding, select W40~W20; for semi-fine grinding, select W10~W3.

5.

5. The method for preparing a fused silica hemispherical resonator according to claim 1, wherein: The polishing comprises: placing the fused quartz hemispherical resonator in a special chemical polishing tool for pretreatment; purging the fused quartz hemispherical resonator with high-purity nitrogen, then immersing it in deionized water, and ultrasonically cleaning it for 10 to 15 minutes; heating the chemical polishing liquid to 35 to 60° C. and keeping it warm; placing the pretreated fused quartz hemispherical resonator together with the tool into the chemical polishing liquid for chemical polishing, with a single polishing time of 6 to 10 minutes; and determining the number of polishing times based on the quality factor value of the fused quartz hemispherical resonator after polishing.

6. The method for preparing a fused silica hemispherical resonator according to claim 1, wherein: The cleaning comprises: placing the fused quartz hemispherical resonator in a special cleaning tool for pre-cleaning; immersing it in a hydrochloric acid solution for ultrasonic cleaning for 15 to 20 minutes, taking it out and cleaning it with deionized water for 2 to 5 minutes, and then blowing it dry with high-purity nitrogen; using a microscope to detect whether there is any residue on the surface of the fused quartz hemispherical resonator, and repeating the pre-cleaning 2 to 3 times depending on the residue; after the pre-cleaning, placing the fused quartz hemispherical resonator in a cleaning solution and soaking it for 2 to 3 hours, rinsing it with deionized water for 2 to 5 minutes, and then blowing it dry with high-purity nitrogen.

7. A fused silica hemispherical resonator prepared by the method for preparing a fused silica hemispherical resonator according to any one of claims 1 to 6.

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