Method for preparing YAG (yttrium aluminum garnet) transparent ceramic optical fiber through rotary jet blowing forming

Abstract

The invention relates to a method for preparing YAG (yttrium aluminum garnet) transparent ceramic optical fibers through rotary jet blowing forming, and belongs to the technical field of preparation of advanced optical functional ceramics. The method disclosed by the invention comprises the following steps: taking Al (NO3) 3.9 H2O and Y (NO3) 3.6 H2O as raw material powder; the preparation method comprises the following steps: dissolving and mixing raw material powder, a sintering aid, a plasticizer and a solvent, adding a binder and acetic acid into the mixture, carrying out hydrothermal high-pressure reaction to obtain ceramic slurry with the solid content of 55-65 wt.%, carrying out rotary jet blowing molding and drying, and carrying out degreasing, glue discharging and vacuum sintering on the obtained YAG optical fiber biscuit to prepare the YAG transparent ceramic optical fiber, the problem of controlling the diameter uniformity of the optical fiber is solved, and the preparation of the in-situ spontaneous shrinkage and solidification ceramic optical fiber with the diameter being less than 50 microns can be directly realized; the long optical fiber can be directly prepared, the preparation efficiency is high, the method is not easily influenced by external application, and the prepared optical fiber product is good in circularity and suitable for industrial application.

Description

Technical Field

[0001] The invention relates to a method for preparing YAG transparent ceramics by rotary spraying and blowing wire forming, belonging to the technical field of advanced optical functional ceramic preparation. Background Art

[0002] At present, the more mature optical fiber materials are mainly quartz glass and single crystals. The preparation methods include in-tube chemical vapor deposition, plasma chemical vapor deposition and axial vapor deposition. The core process is to prefabricate the optical fiber rod, then heat and soften it in a high-temperature furnace, pull it into a long filament, and then carry out coating, sheathing and other processes to make the optical fiber core. The extremely low thermal conductivity of quartz optical fiber (1.38W m -1 K -1 ), resulting in large thermal gradients, optical distortion, thermal lens effects and other phenomena in the optical fiber products made from them during long-term operation, resulting in a decrease in beam quality. The preparation process of single-crystal optical fiber requires the use of temperatures above the melting point, which has problems such as complex production processes, high equipment requirements, and high energy consumption. In addition, due to the existence of the segregation coefficient of the single-crystal material itself, single-crystal optical fiber materials with high doping concentrations and high-power lasers cannot be prepared, which limits the development of the optical fiber technology industry.

[0003] In order to solve the above problems, Chinese patent application CN116857594A discloses a hollow fluorescent ceramic for laser lighting and a preparation method thereof. The basic principle is to prepare a hollow optical fiber material with an inner diameter of 50 to 100 μm and an outer diameter of 200 to 500 μm by implementing an extrusion molding process through the structural design of the extrusion port. However, the optical fiber material prepared by this process is a hollow structure with a rough surface. Due to the structural design of the plunger pump and the extrusion port, it is impossible to prepare an optical fiber material with a diameter of less than 50 μm. In addition, the slurry is separated from the constraint condition after being extruded from the extrusion port, and the slurry has an elastic aftereffect phenomenon (i.e., the slurry expands after being extruded from the extrusion port). Chinese patent application CN114779410A discloses a ceramic optical fiber preparation method based on 3D gel printing technology. The basic principle is to use a 3D printing process to print out an optical fiber from a ceramic slurry used in a gel molding system. The design purpose is to solve the problem of external force deformation during the gel process. However, the optical fiber printing speed of this technical route is slow and is not suitable for industrial mass production. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for preparing YAG transparent ceramics by rotary jet blowing, which has high preparation efficiency and good roundness of the prepared optical fiber product, and is suitable for industrial application.

[0005] The method for preparing YAG transparent ceramics by spin-jet blowing filament molding of the present invention comprises the following steps:

[0006] S1: According to the stoichiometric ratio Y3Al5O 12 Weigh Al(NO3)3·9H2O and Y(NO3)3·6H2O as raw material powders respectively;

[0007] S2: dissolving and mixing raw material powder, sintering aid, plasticizer and solvent to form a uniform mixed solution A;

[0008] S3: adding a binder and acetic acid to the mixed solution A obtained in S2, performing a hydrothermal high-pressure reaction, and then separating out water and filtering to obtain a ceramic slurry with a solid content of 55 to 65 wt.%;

[0009] S4: vacuum degassing the ceramic slurry obtained in S3, and then performing spin-blowing forming and drying to obtain a YAG optical fiber blank;

[0010] S5: Degreasing and debonding the YAG optical fiber blank obtained in S4 and performing vacuum sintering to obtain a YAG transparent ceramic optical fiber.

[0011] Preferably, the sum of the masses of Al(NO3)3·9H2O and Y(NO3)3·6H2O in S1 accounts for 10 to 30 wt.% of the total mass of the solution.

[0012] Preferably, the sintering aid in S2 is one or both of Mg(NO3)2·6H2O and ethyl orthosilicate, and the amount of Mg(NO3)2·6H2O added is Y3Al5O 12 0.05-0.15wt.% of the total mass, the amount of tetraethyl orthosilicate added is 0.05-0.1wt.% of the total mass of Y2O3 and Al2O3, the plasticizer is polyethylene glycol, and the solvent is one or both of anhydrous ethanol and water.

[0013] Preferably, the binder in S3 is polyvinyl alcohol (PVA), and the amount of acetic acid added is Y3Al5O 12 The total mass is 1.0-3.0wt.%, the hydrothermal temperature of the hydrothermal high-pressure reaction is 70-80°C, the reactor pressure is 20-40Mpa, and the reaction time is 1.5-3.0h.

[0014] Preferably, the rotary spray-blown filament forming in S4 is carried out by a rotary spray-blown filament forming machine, the rotation speed of the rotary spray-blown filament forming machine is 2000-5000r / min, the pressure is 30-50Mpa, and the drying includes a three-stage drying procedure, the temperature of the first drying chamber is 50-60°C, the temperature of the second drying chamber is 80-90°C, and the temperature of the third drying chamber is 90-100°C.

[0015] Preferably, the sintering temperature of the vacuum sintering in S5 is 1680-1780° C., the insulation time is 6-10 hours, and air annealing is performed.

[0016] Preferably, the nozzle diameter of the rotary jet blowing machine is 0.6-1.0 mm, and the nozzle length is 40-60 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention uses rotary spraying to form a filament, and can realize continuous preparation of ceramic optical fibers without using a mold or an extrusion nozzle with a special structure, and there is no elastic aftereffect phenomenon in the optical fiber forming process; the optical fiber spontaneously solidifies and shrinks after extrusion, and a high initial density ceramic blank is directly prepared. The initial relative density of the prepared ceramic blank after degreasing and debinding is higher than 52%, which can meet the requirements of high-quality ceramic optical fiber preparation;

[0019] (2) Compared with similar ceramic optical fiber preparation methods, the present invention has a fast preparation speed, a green and environmentally friendly preparation process, and the high molecular organic matter used is non-toxic and has no irritating odor; the preparation process is simple and easy to control; the prepared ceramic optical fiber has high optical transmittance, a smooth surface, good roundness, and uniform thickness, and is expected to realize the industrial production of ceramic optical fibers;

[0020] (3) The present invention prepares a ceramic solution based on a water-soluble material, and obtains a ceramic slurry containing fine gel by heating and modifying the solution. The preparation process of the present invention does not introduce impurities or organic matter that cannot be removed, and the prepared solution components are uniform, without precipitation and agglomerates.

[0021] (4) The design principle of the present invention is based on the shrinkage effect of the surface tension of the slurry droplets and the spontaneous solidification effect of the slurry itself, which solves the problem of controlling the uniform diameter of the optical fiber and can directly realize the preparation of ceramic optical fibers with a diameter of less than 50 μm and in-situ spontaneous shrinkage and solidification. The present invention can directly realize the preparation of long optical fibers with high preparation efficiency and is not easily affected by external applications. The prepared optical fiber products have good roundness and are suitable for industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a physical picture of the ceramic optical fiber prepared in Example 1;

[0023] Figure 2 is a schematic diagram of the diameter measurement of the ceramic optical fiber prepared in Example 1;

[0024] Figure 3 These are the side SEM test result diagrams of the ceramic optical fibers prepared in Example 1 and Example 2, wherein (a) is the microstructure diagram of the ceramic optical fiber prepared in Example 1, (a') is a partial enlarged diagram of Figure a, (b) is the microstructure diagram of the ceramic optical fiber prepared in Example 2, and (b') is a partial enlarged diagram of Figure b. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] Step 1: Using commercial high-purity Al(NO3)3·9H2O, Y(NO3)3·6H2O, TEOS, Mg(NO3)2·6H2O, PEG-4000, acetic acid, and deionized water as raw materials, TEOS was added to anhydrous ethanol at a volume ratio of 1:10; PEG-4000 was dissolved in deionized water at a mass ratio of 1:20, and stirred for 3 hours;

[0028] Step 2: Al(NO3)3·9H2O and Y(NO3)3·6H2O in the stoichiometric ratio Y3Al5O 12 Add the PEG-4000 aqueous solution obtained in step 1 to adjust the amount of metal nitrate to 30% of the total mass of the solution; continue stirring for 2 hours; add Mg(NO3)2·6H2O, the amount of Mg(NO3)2·6H2O added is Y3Al5O 12 0.1wt.% of the total mass, stirring was continued for 1h; TEOS alcohol solution was added, and the amount of TEOS added was Y3Al5O 12 0.05wt.% of the total mass, and continue stirring for 2h;

[0029] Step 3: Heat and dissolve PVA, then add it to the ceramic solution obtained in step 2, and add Y3Al5O 12 The total mass of acetic acid is 2.0%, and a hydrothermal high-pressure reactor is used for reaction, the hydrothermal temperature is set to 75°C, the reactor pressure is 30Mpa, and the reaction time is 2.0h; the obtained solution is subjected to water analysis to obtain a ceramic slurry, and the water analysis is carried out by vacuum drying, using a vacuum drying cabinet, maintaining the environment at 150Pa, and the vacuum drying temperature is 60°C; the slurry solid content is adjusted to 60wt.%, and then filtered, the filtration mesh is 600 mesh, and the obtained ceramic slurry for rotary spray blowing is obtained;

[0030] Step 4: vacuum degas the slurry obtained in step 3, and then add it into a rotary spray blowing machine, use a nozzle with a diameter of 0.8 mm and a nozzle length of 40 mm, set the rotary spray machine speed to 3000 r / min, the pressure to 40 MPa, set a three-stage drying program, the first drying chamber hot air temperature is 55°C, the second drying chamber hot air temperature is 85°C, and the third drying chamber temperature is 90°C, to obtain a YAG optical fiber blank;

[0031] Step 5: Degrease and debind the optical fiber blank obtained in step 4, and then perform vacuum sintering at a temperature of 1720°C for 8 hours, and then perform air annealing at a temperature of 1400°C for 10 hours to obtain a YAG transparent ceramic optical fiber.

[0032] like Figure 1 As shown, the optical fiber produced in this embodiment has good linearity and high optical transmittance, and the text under the optical fiber is clearly visible;

[0033] like Figure 2 As shown, a ceramic optical fiber with a diameter of 100 microns is successfully prepared by the preparation method disclosed in this embodiment. The optical fiber has good mechanical properties and can meet the use requirements of subsequent processing;

[0034] like Figure 3 As shown in (a) and (a'), from the microscopic images, the obtained ceramic optical fiber has a uniform grain structure and no pores or impurity secondary phases exist.

[0035] Example 2

[0036] Step 1: Using commercial high-purity Al(NO3)3·9H2O, Y(NO3)3·6H2O, TEOS, Mg(NO3)2·6H2O, PEG-4000, acetic acid, and deionized water as raw materials, TEOS was added to anhydrous ethanol at a volume ratio of 1:5; PEG-4000 was dissolved in deionized water at a mass ratio of 1:40, and stirred for 3 hours;

[0037] Step 2: Al(NO3)3·9H2O and Y(NO3)3·6H2O in the stoichiometric ratio Y3Al5O 12 Add to the PEG-4000 aqueous solution obtained in step 1, and adjust the amount of metal nitrate added to 30% of the total mass of the solution; continue stirring for 2 hours; add Mg(NO3)2·6H2O, the amount of Mg(NO3)2·6H2O added is Y3Al5O 12 0.15wt.% of the total mass, stirring was continued for 1h; TEOS alcohol solution was added, and the amount of TEOS added was Y3Al5O 12 0.05wt.% of the total mass, and continue stirring for 2h;

[0038] Step 3: Heat and dissolve PVA, then add it to the ceramic solution obtained in step 2, and add Y3Al5O 12The total mass of 3.0% acetic acid is reacted in a hydrothermal high-pressure reactor, the hydrothermal temperature is set to 70°C, the reactor pressure is 40Mpa, and the reaction time is 3.0h; the obtained solution is subjected to water analysis to obtain a ceramic slurry, which is precipitated by vacuum drying, using a vacuum drying cabinet, maintaining the environment at 300Pa, and the vacuum drying temperature is 80°C; the slurry solid content is adjusted to 55wt.%, and then filtered, the filtration mesh is 800 mesh, and the obtained ceramic slurry for spin-jet blowing is obtained;

[0039] Step 4: Vacuum degas the slurry obtained in step 3, and then add it to the rotary spray blowing machine. The diameter of the rotary spray blowing machine nozzle is 1.0mm, and the nozzle length is 60mm. Set the rotary spray machine speed to 5000r / min, the pressure to 50Mpa, and set a three-stage drying program. The hot air temperature of the first drying chamber is 50℃, the hot air temperature of the second drying chamber is 80℃, and the temperature of the third drying chamber is 95℃ to obtain the YAG optical fiber blank;

[0040] Step 5: Degrease and debind the optical fiber blank obtained in step 4, and then perform vacuum sintering at a temperature of 1780°C for 10 hours, and then perform air annealing at a temperature of 1400°C for 10 hours to obtain a YAG transparent ceramic optical fiber.

[0041] As attached Figure 3 As shown in (b) and (b'), the optical fiber prepared in this embodiment has the same advantages as the optical fiber prepared in the previous embodiment, such as uniform grain structure, no pores and impurity secondary phase.

Claims

1. A method for preparing YAG transparent ceramic optical fiber by spin-jet blowing, characterized in that: The method for preparing YAG transparent ceramic optical fiber by using a spin-jet blowing method comprises the following steps: S1: According to the stoichiometric ratio Y3Al5O 12 Weigh Al(NO3)3·9H2O and Y(NO3)3·6H2O as raw material powders respectively; S2: dissolving and mixing raw material powder, sintering aid, plasticizer and solvent to form a uniform mixed solution A; S3: adding a binder and acetic acid to the mixed solution A obtained in S2, performing a hydrothermal high-pressure reaction, and then separating out water and filtering to obtain a ceramic slurry with a solid content of 55 to 65 wt.%; S4: vacuum degassing the ceramic slurry obtained in S3, and then performing spin-blowing forming and drying to obtain a YAG optical fiber blank; S5: Degreasing and debinding the YAG optical fiber blank obtained in S4, vacuum sintering, and finally air annealing to obtain a YAG transparent ceramic optical fiber.

2. The preparation method according to claim 1, characterized in that: The sum of the masses of Al(NO3)3·9H2O and Y(NO3)3·6H2O described in S1 accounts for 10 to 30 wt.% of the total mass of the solution.

3. The preparation method according to claim 1, characterized in that: The sintering aid described in S2 is one or two of Mg(NO3)2·6H2O and tetraethyl orthosilicate, the added amount of Mg(NO3)2·6H2O is 0.05~0.15wt.% of the total mass of Y2O3 and Al2O3, the added amount of tetraethyl orthosilicate is 0.05~0.1wt.% of the total mass of Y2O3 and Al2O3, the plasticizer is polyethylene glycol with a molecular weight of 4000-8000, and the solvent is one or two of anhydrous ethanol and water.

4. The preparation method according to claim 1, characterized in that: The binder in S3 is polyvinyl alcohol, the amount of acetic acid added is 1.0-3.0wt.% of the total mass of Y2O3 and Al2O3, the hydrothermal temperature of the hydrothermal high-pressure reaction is 70-80°C, the reactor pressure is 20-40Mpa, and the reaction time is 1.5-3.0h.

5. The preparation method according to claim 1, characterized in that: The rotary spray-blown filament forming in S4 is carried out by a rotary spray-blown filament forming machine, the rotation speed of the rotary spray-blown filament forming machine is 2000-5000r / min, the pressure is 30-50Mpa, and the drying includes a three-stage drying procedure, the temperature of the first drying chamber is 50-60°C, the temperature of the second drying chamber is 80-90°C, and the temperature of the third drying chamber is 90-100°C.

6. The preparation method according to claim 1, characterized in that: The sintering temperature of the vacuum sintering in S5 is 1680-1780° C., and the insulation time is 6-10 hours.

7. The preparation method according to claims 1-6, characterized in that: The nozzle diameter of the rotary jet blowing machine is 0.6-1.0 mm, and the nozzle length is 40-60 mm.

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