Preparation method of in-situ modified and reinforced atomic gas chamber glass bulb

Abstract

The invention discloses a preparation method of an in-situ modified and reinforced atomic gas chamber glass bulb, and belongs to the field of atomic gas chamber preparation. According to the method, the atomic gas chamber glass bulb is subjected to composite treatment such as high-temperature shot blasting, ion replacement, high-temperature annealing, magnetorheological polishing and ultrasonic cleaning, in-situ strengthening of the atomic gas chamber glass bulb is achieved, the helium leakage rate, alkali corrosion resistance, chemical stability and light transmittance of the atomic gas chamber glass bulb are comprehensively improved, and the working life of the atomic gas chamber glass bulb is comprehensively prolonged.

Description

Technical Field

[0001] This invention relates to a method for preparing an in-situ modified and strengthened atomic gas cell glass shell, belonging to the field of atomic gas cell preparation. Background Technology

[0002] The atomic gas cell is a core component of quantum precision measuring instruments such as atomic interferometers, atomic clocks, and atomic gyroscopes. It is typically a glass shell filled with alkali metals and buffer gases (mainly spherical, cylindrical, or cubic structures), serving as the physical site for atomic polarization, spin exchange, spin relaxation, and spin precession. The performance of the atomic gas cell has a decisive influence on the performance of quantum instruments and is currently key to improving their performance and bringing them to practical application.

[0003] Currently, atomic cell glass shells are mainly prepared through methods such as flame firing and direct bonding. Glass, as a hard and brittle material, is difficult to process, and its millimeter-scale dimensions further increase the processing difficulty. Therefore, atomic cell glass shells suffer from a series of common defects in mechanical properties, optical properties, and service life. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose an in-situ modified and strengthened method for preparing atomic gas chamber glass shells. Through the combined effects of high-temperature shot peening, ion replacement, magnetorheological polishing and high-temperature annealing, the in-situ strengthening of the atomic gas chamber glass shell is achieved, which comprehensively improves the helium leakage rate, alkali corrosion resistance, chemical stability, light transmittance and working life of the atomic gas chamber glass shell.

[0005] The technical solution of this invention is:

[0006] A method for preparing an in-situ modified and strengthened atomic gas cell glass shell includes:

[0007] The outer surface of the glass shell of the atomic gas chamber was strengthened by high-temperature shot peening and then removed after cooling to room temperature. The shot peening used glass powder with a particle size of 20,000 to 25,000 mesh and a composition of Al2O3 and SiO2. The heating temperature was 660±10℃. The shot peening distance was 75 mm to 100 mm, the shot peening angle was greater than 70°, and the shot peening time was selected as 2 to 2.4 times the saturated shot peening time.

[0008] RbNO3 solution was injected into the glass shell of the atomic gas chamber after high-temperature shot peening. After the particle replacement reaction was completed, the solution was poured out, washed with deionized water and dried.

[0009] The dried atomic gas chamber glass shell was then subjected to high-temperature annealing, ultrasonic-assisted magnetorheological polishing, and ultrasonic cleaning.

[0010] Furthermore, the outer surface of the glass shell of the atomic gas chamber is strengthened by high-temperature shot peening, with a shot peening intensity of 0.25A to 0.3A during the process.

[0011] Further, RbNO3 solution was injected into the glass shell of the atomic gas chamber, heated to 77℃~80℃, and allowed to stand for 10min~15min before the solution was poured out, washed with deionized water and dried.

[0012] Furthermore, the RbNO3 solution is a saturated solution with a purity of 99.9%. During heating, care should be taken to keep the container sealed to reduce the amount of water evaporation.

[0013] Further, the glass shell of the atomic gas chamber is placed in a vacuum annealing furnace, a vacuum is drawn, and heating is started for high-temperature annealing. The temperature is raised to 530℃~560℃ and held at that temperature. Then, it is cooled to room temperature in the furnace and removed.

[0014] Furthermore, the vacuum degree of the vacuum annealing furnace is better than 0.1 Pa, and the heating rate during the heating process is between 8℃ / min and 12℃ / min.

[0015] Furthermore, ultrasonic-assisted magnetorheological polishing was performed at a polishing pressure of 25 kPa to 40 kPa and a polishing speed of 0.1 m / s to 0.15 m / s.

[0016] Furthermore, the polishing slurry contains core-shell abrasive particles formed by amorphous SiO2 coated on Fe3O4, with a particle size of 30nm–50nm and a particle size of 5wt%.

[0017] Further, ultrasonic cleaning is performed using anhydrous ethanol as the cleaning solvent, repeated 2-3 times; then the ultrasonically cleaned atomic gas chamber glass shell is baked to dry the moisture for later use.

[0018] Furthermore, the shape, airtightness, and transmittance of the ultrasonically cleaned atomic gas cell glass shell were tested. The shell showed no defects, cracks, or chipping, and the transmittance was greater than 85% at 400–1100 nm. The airtightness was better than 1E-13 Pa·m. 3 / s, all three conditions must be met for it to be considered qualified.

[0019] The advantages of this invention compared to the prior art are:

[0020] (1) The atomic gas chamber glass shell treated by this method is subjected to high-temperature shot peening to form a dense layer, which can increase the alumina content on the outer surface of the atomic gas chamber glass shell and effectively improve the mechanical strength and helium leakage rate of the atomic gas chamber glass shell.

[0021] (2) The atomic gas chamber glass shell treated by this method, through ion replacement, replaces sodium atoms in the inner wall of the atomic gas chamber glass shell with rubidium atoms, which can significantly improve chemical stability and alkali resistance. When the atomic gas chamber is filled with alkali metal, the reaction between the alkali metal and the glass components can be effectively inhibited, thus extending the working life of the atomic gas chamber.

[0022] (3) The atomic gas cell glass shell treated by this method is polished by ultrasonic-assisted magnetorheological polishing on both the inner and outer walls of the atomic gas cell glass shell to reduce its surface roughness and improve the light transmission performance of the atomic gas cell glass shell.

[0023] (4) The atomic gas chamber glass shell treated by this method can reduce the residual stress of the atomic gas chamber glass shell by high temperature annealing, which can effectively avoid cracking and breakage caused by stress release and extend the working reliability of the atomic gas chamber. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0025] Figure 1 This is a schematic diagram of an in-situ modified and strengthened atomic gas cell glass shell preparation method according to an embodiment of the present invention;

[0026] Figure 2 This is a typical physical image of the glass shell of the atomic gas chamber in an embodiment of the present invention. Detailed Implementation

[0027] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0028] The glass shell of the atomic gas chamber is made of borosilicate glass (grade BF33); common shapes include spheres, cylinders, and cuboids, with sizes ranging from millimeters to decimeters; structurally, it can be divided into a shell and an inflatable tube, such as... Figure 2 As shown, the two are connected, and after the atomic gas chamber glass shell is filled, it is fused and removed from the root of the filling capillary tube. To improve the overall performance and yield of the atomic gas chamber glass shell, this invention proposes an in-situ modified and strengthened method for preparing the atomic gas chamber glass shell. The method involves designing and preparing the glass shell, as detailed below. Figure 1 As shown, it includes the following steps:

[0029] (1) The outer surface of the glass shell of the atomic gas chamber is subjected to high-temperature shot peening and then cooled to room temperature before being removed. The shot peening uses glass powder with a particle size of 20,000-25,000 mesh and a composition of 70% Al₂O₃ + 30% SiO₂; the heating temperature is 660±10℃, with a temperature control accuracy better than 5℃. The shot peening distance is 75mm-100mm, the shot peening angle is >70°, the shot peening intensity is 0.25A-0.3A, and the shot peening time is 2-2.4 times the saturation shot peening time (in engineering, the time required to achieve 98% coverage of the bullet marks on the treated sample is called the saturation shot peening time). The purpose of this step is to improve the surface density, thereby reducing He permeability. Existing high-temperature shot peening technology is mainly applied to metallic materials. This invention applies this technology to glass materials without a fixed melting point, with the main improvements being: firstly, changing the shot peening material to use ultrafine glass powder; and secondly, setting more gentle and reasonable shot peening parameters, such as shot peening temperature, distance, angle, and time, for more fragile materials.

[0030] (2) Inject RbNO3 solution into the glass shell of the shot-peened atomic gas chamber, heat to 80°C, let stand for 10-15 minutes, then pour out the solution, wash with deionized water and air dry. The RbNO3 solution is a saturated solution with a purity of 99.9%. Ensure sealing during heating to minimize water evaporation. The purpose of this step is to enhance its chemical stability through an ion replacement reaction. While KNO3, NaCl, and CuSO4 are commonly used for replacement reactions, RbNO3 solution is better suited for the subsequent infusion of elemental Rb. This injection step can suppress the subsequent Rb infusion reaction in space, thus improving the service life of the atomic gas chamber.

[0031] (3) The ion-substituted atomic gas cell glass shell is placed in a vacuum annealing furnace, evacuated, and heated to 550°C. After holding at this temperature for 90 minutes, it is cooled to room temperature in the furnace and then removed. The vacuum degree of the vacuum annealing furnace is better than 0.1 Pa, and the heating rate is between 8°C / min and 12°C / min. The purpose of this step is to reduce its residual stress through high-temperature annealing.

[0032] (4) The annealed atomic gas cell glass shell is placed in a polishing machine for ultrasonic-assisted magnetorheological polishing, and then removed after completion. The polishing pressure is 25 kPa to 40 kPa, the polishing speed is 0.1 m / s to 0.15 m / s, and the polishing time is 4 h. The polishing solution contains amorphous SiO2 coated on Fe3O4 core-shell abrasive particles with a particle size of 30 nm to 50 nm and a wt% content. The ultrasonic vibration frequency is 20 kHz and the amplitude is 30 μm. The purpose of this step is to reduce the surface roughness so that its transmittance meets the light transmission requirements.

[0033] (5) Put the polished atomic cell glass shell into an ultrasonic cleaning machine for ultrasonic cleaning. The cleaning solvent is 99.99% anhydrous ethanol, the ultrasonic frequency is 40 kHz, the ultrasonic power is 15 W, and the ultrasonic time is 15 min. Repeat 2 - 3 times. Bake the cleaned atomic cell glass shell at 120 °C for 2 h to dry the moisture for standby. The purpose of this step is to remove the impurities attached to the inner and outer walls to improve its cleanliness.

[0034] (6) Detect the appearance, airtightness, light transmittance and other indicators of the atomic cell glass shell. There are no defects, cracks or chipping on the outer surface, the transmittance > 85% @ 400 - 1100 nm, and the airtightness is better than 1E-13 Pa·m 3 / s. Only when all three items meet the requirements can it be considered qualified. Reject unqualified samples.

[0035] Through the combined effects of high-temperature shot peening, ion replacement, magnetorheological polishing and high-temperature annealing, etc., the in-situ strengthening of the atomic cell glass shell is realized, and the comprehensive improvement of its helium leakage rate, alkali corrosion resistance, chemical stability, light transmittance and working life is achieved. Among them:

[0036] By high-temperature shot peening treatment, a dense layer is formed to increase the alumina content on the outer surface of the atomic cell glass shell, which can effectively improve the mechanical strength and helium leakage rate of the atomic cell glass shell.

[0037] By ion replacement, the sodium atoms in the inner wall of the atomic cell glass shell are replaced by rubidium atoms, which can significantly improve the chemical stability and alkali resistance. When the atomic cell is filled with alkali metal, the reaction between the alkali metal and the glass components can be effectively inhibited, and the working life of the atomic cell can be extended.

[0038] By ultrasonic-assisted magnetorheological polishing, the inner and outer walls of the atomic cell glass shell are polished simultaneously to reduce its surface roughness and improve the light transmission performance of the atomic cell glass shell.

[0039] By high-temperature annealing treatment, the residual stress of the atomic cell glass shell is reduced, which can effectively avoid cracking and breaking caused by stress release and improve the working reliability of the atomic cell.

[0040] The above embodiments are only the more preferred specific embodiments of the present invention. The common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an in-situ modified and strengthened atomic gas cell glass shell, characterized in that, include: The outer surface of the glass shell of the atomic gas chamber was strengthened by high-temperature shot peening and then removed after cooling to room temperature. The shot peening used glass powder with a particle size of 20,000 to 25,000 mesh and a composition of Al2O3 and SiO2. The heating temperature was 660±10℃. The shot peening distance was 75 mm to 100 mm, the shot peening angle was greater than 70°, and the shot peening time was selected as 2 to 2.4 times the saturated shot peening time. RbNO3 solution was injected into the glass shell of the atomic gas chamber after high-temperature shot peening. After the particle replacement reaction was completed, the solution was poured out, washed with deionized water and dried. The dried atomic gas chamber glass shell was then subjected to high-temperature annealing, ultrasonic-assisted magnetorheological polishing, and ultrasonic cleaning.

2. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 1, characterized in that, The outer surface of the glass shell of the atomic gas chamber is strengthened by high-temperature shot peening. During the process, the shot peening intensity is 0.25A to 0.3A.

3. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 1, characterized in that, Inject RbNO3 solution into the glass shell of the atomic gas chamber, heat to 77℃~80℃, let stand for 10min~15min, pour out the solution, wash with deionized water and air dry.

4. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 3, characterized in that, The RbNO3 solution is a saturated solution with a purity of 99.9%. During heating, ensure the container is sealed to minimize water evaporation.

5. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 1, characterized in that, The glass shell of the atomic gas chamber is placed in a vacuum annealing furnace, and after evacuation, it is heated to perform high-temperature annealing. The temperature is raised to 530℃~560℃ and held at that temperature. Then it is cooled to room temperature with the furnace and removed.

6. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 5, characterized in that, The vacuum annealing furnace has a vacuum level better than 0.1 Pa, and the heating rate during the heating process is between 8℃ / min and 12℃ / min.

7. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 1, characterized in that, The annealed atomic gas cell glass shell is placed in a polishing machine for ultrasonic-assisted magnetorheological polishing at a pressure of 25 kPa to 40 kPa and a polishing speed of 0.1 m / s to 0.15 m / s.

8. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 7, characterized in that, The polishing slurry contains amorphous SiO2 coated on Fe3O4 core-shell abrasive particles with a particle size of 30nm to 50nm.

9. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 1, characterized in that, After polishing, the glass shell of the atomic gas chamber is placed in an ultrasonic cleaner for ultrasonic cleaning. Anhydrous ethanol is used as the cleaning solvent. The process is repeated 2 to 3 times. Then, the ultrasonically cleaned glass shell of the atomic gas chamber is baked to dry it and set it aside for later use.

10. The method for preparing an in-situ modified and strengthened atomic gas cell glass shell according to claim 1, characterized in that, The atomic gas cell glass shell, after ultrasonic cleaning, was inspected for shape, airtightness, and transmittance. The shell was free of defects, cracks, or chipping. The transmittance was greater than 85% at 400–1100 nm, and the airtightness was better than 1E-13 Pa·m. 3 / s, all three conditions must be met for it to be considered qualified.

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