阅读说明：本技术 一种均匀包覆的AlON粉体及其透明陶瓷的制备方法 (Preparation method of uniformly coated AlON powder and transparent ceramic thereof ) 是由 杨章富 卜国秀 李克 李新柱 史杨龙 朱朝东 李伟杰 杨思琪 于 2021-11-03 设计创作，主要内容包括：本发明涉及一种均匀包覆的AlON粉体及其透明陶瓷的制备方法,该方法主要包括如下步骤：以去离子水为分散介质,基于非均匀形核理论采用化学沉淀法在磷酸抗水解处理的AlON粉体表面非均匀形核沉积致密的烧结助剂或激活剂的前驱体,均匀包覆的AlON粉体经成型后在1780-1950℃高温烧结数小时得到AlON高透明陶瓷。相比传统引入方式,本发明能提高烧结助剂或激活剂在AlON陶瓷中的均匀性,可有效避免差分烧结,不仅能抑制晶粒异常长大及其导致的晶内孔的生成,也可减少第二相的析出从而提高透明度和提高激活离子的掺杂浓度。本发明工艺简单、健康环保、可重复性强、烧结温度相对较低,所制备的AlON透明陶瓷光学透过率高、力学性能好、发光效率高。(The invention relates to a method for preparing uniformly coated AlON powder and transparent ceramics thereof, which mainly comprises the following steps: the method comprises the steps of taking deionized water as a dispersion medium, adopting a chemical precipitation method based on a non-uniform nucleation theory to non-uniformly nucleate and deposit a compact sintering aid or a precursor of an activator on the surface of AlON powder subjected to hydrolysis resistance treatment by phosphoric acid, and sintering the uniformly coated AlON powder at 1780-1950 ℃ for several hours to obtain the AlON high-transparency ceramic. Compared with the traditional introduction mode, the method can improve the uniformity of the sintering aid or the activator in the AlON ceramic, effectively avoid differential sintering, inhibit abnormal growth of crystal grains and generation of intracrystalline pores caused by the abnormal growth of the crystal grains, and reduce the precipitation of a second phase so as to improve the transparency and improve the doping concentration of the activated ions. The method has the advantages of simple process, health, environmental protection, strong repeatability and relatively low sintering temperature, and the prepared AlON transparent ceramic has high optical transmittance, good mechanical property and high luminous efficiency.)

1. A preparation method of uniformly coated AlON powder and transparent ceramics thereof is characterized by comprising the following steps:

(1) weighing a proper amount of AlON powder, putting the AlON powder into a phosphoric acid solution with the concentration of 0.5-3 wt.%, magnetically stirring for 10-30min at normal temperature, and centrifugally filtering and drying to obtain the hydrolysis-resistant hydrophilic AlON powder. Wherein the mass ratio of the AlON powder to the phosphoric acid solution is 1: 2-20;

(2) and (2) mixing the AlON powder obtained in the step (1) with deionized water and a dispersing agent, and performing ultrasonic dispersion for 10-30min to obtain a highly dispersed suspension. Wherein the mass ratio of AlON to deionized water is 1: 3;

(3) weighing nitrate of M ions, dissolving the nitrate in deionized water to obtain a solution A, and pouring the solution A into the suspension obtained in the step (2) to form a suspension B. Wherein the mass ratio of AlON to deionized water in the suspension B is 1: 3-10;

(4) preparing 0.002-0.2 mol/l of precipitator solution C, dropwise adding the precipitator solution C into the suspension B obtained in the step (3) at a rate of 1-10ml/min, violently stirring in the dropwise adding process until the PH value reaches a set value or the precipitator is excessive, and then continuously stirring for 1-4h, carrying out centrifugal washing and drying to obtain AlON powder uniformly coated with M ions;

(5) forming the AlON powder obtained in the step (4), and removing glue in the air at 650 ℃ for 1-10h to obtain an AlON biscuit;

(6) placing the AlON biscuit obtained in the step (5) in N₂Sintering at high temperature of 1780 and 1950 ℃ in the atmosphere, preserving the heat for 1-12h, cooling along with the furnace, grinding and polishing to obtain the AlON transparent ceramic.

2. The method for preparing the uniformly coated AlON powder and the transparent ceramic thereof according to claim 1, is characterized in that: the molecular formula of AlON in the step (1) is Al_(64+3)/xO_32-xN_xWherein x is more than or equal to 2.5 and less than or equal to 5, and the average particle size of the powder is less than 3 mu m.

3. The method for preparing the uniformly coated AlON powder and the transparent ceramic thereof according to claim 1, is characterized in that: the dispersing agent in the step (2) is one of PEG2000, ammonium polyacrylate and ammonium polymethacrylate, and the content of the dispersing agent accounts for 0.1-2 wt% of the AlON powder.

4. The method for preparing the uniformly coated AlON powder and the transparent ceramic thereof according to claim 1, is characterized in that: the M ion in the step (3) is Mg²⁺、Ca²⁺、Sr²⁺、Ba²⁺、Mn²⁺、Sc³⁺、Y³⁺、La³⁺、Ce³⁺、Eu³⁺、Pr³⁺、Sm^{3 +}、Gd³⁺、Tb³⁺、Dy³⁺、Ho³⁺、Er³⁺、Tm³⁺、Yb³⁺、Lu³⁺、Zr⁴⁺One or more nitrate with purity higher than 99% and oxide mass converted from nitrate is 0.04-0.7 wt.% of AlON powder.

5. The method for preparing the uniformly coated AlON powder and the transparent ceramic thereof according to claim 1, is characterized in that: and (4) the solution D in the step (4) is one of ammonia water, ammonium carbonate and ammonium phosphate solution.

6. The method for preparing the uniformly coated AlON powder and the transparent ceramic thereof according to claim 1, is characterized in that: the forming in the step (5) is one of dry pressing, slip casting and gel injection molding, wherein cold isostatic pressing is needed after the dry pressing.

7. The method for preparing the uniformly coated AlON powder and the transparent ceramic thereof according to claim 1, is characterized in that: and (3) the sintering in the step (6) is pressureless sintering, hot pressing sintering or spark plasma sintering, or the sintering is combined with hot isostatic pressing sintering.

Technical Field

The invention relates to uniformly coated AlON powder and a method for preparing transparent ceramic by the same, belonging to the field of transparent ceramic and solid illumination/display.

Background

The aluminum oxynitride (AlON) transparent ceramic not only has the excellent characteristics of high hardness, high strength, good chemical stability and the like, but also has excellent optical transmittance in the near ultraviolet-middle infrared wavelength range (0.2-6 mu m), and the theoretical transmittance of the aluminum oxynitride transparent ceramic exceeds 85 percent. AlON structural transparent ceramics have been considered as a preferred material for high temperature infrared windows, missile hoods and bullet proof transparent armors. The AlON fluorescent transparent ceramic doped with the active ions also becomes a high-power solid-state lighting/displaying fluorescent material with very high potential.

At present, the transparent ceramics with AlON structure is mainly prepared by adopting a two-step method, namely synthesizing AlON powder and then sintering at high temperature. In order to enhance the optical transmittance by promoting the densification as much as possible, a small amount of a sintering aid is generally added to the AlON powder. The sintering aid is generally introduced by the following method: oxide, carbonate or nitrate containing sintering aid ions is added into AlON powder, and the mixture is subjected to wet ball milling and mixing by taking absolute ethyl alcohol or deionized water and the like as a dispersion medium [ Y, Shan et al.Script.Mater.,2018,157, 148-. The introduction method of the wet ball milling is simple and convenient, however, even if the particle size of the sintering aid particles is reduced or soluble nitrate is used, the uniform distribution of the sintering aid is still difficult to ensure. In addition, when the colloidal forming technique is adopted, the surface characteristics of the AlON and the sintering aid are considered synergistically, otherwise uniform suspension is difficult to achieve. The differential sintering of the AlON ceramic in the heating and heat preservation process is easy to occur due to the uneven distribution of the sintering aids. On one hand, in a partial area where the sintering aid is absent, due to the lack of mass transfer effects such as inhibiting the movement of a grain boundary and promoting the diffusion of the grain boundary or volume diffusion, the growth of grains is easy to be too fast, so that intracrystalline pores which are difficult to discharge are formed; on the other hand, in a partial region where the sintering aid is excessive, the content may be too high to easily generate a second phase at the grain boundary, resulting in an influence on the optical transmission performance. For the preparation of the AlON fluorescent transparent ceramic, an appropriate amount of oxide, carbonate or nitrate containing active ions, which can also be used as a sintering aid, is generally added into AlON powder for wet ball milling [ zhangfang et al, CN200910247864.2,2009], so the above problems are also generated, and more importantly, the uneven distribution of the active ions may generate concentration quenching due to too high local concentration, which seriously affects the light emitting effect.

Disclosure of Invention

Aiming at the problems caused by the difficulty in uniform distribution of the sintering aid or the activating ion-containing substance in the AlON powder in the traditional adding mode, the invention aims to provide a method for uniformly coating the sintering aid or the activating ion-containing AlON powder by a chemical precipitation method, and the powder can be used for preparing AlON high-transparency ceramic.

In order to achieve the purpose, the technical scheme of the invention is as follows: a preparation method of uniformly coated AlON powder and transparent ceramics thereof is characterized by comprising the following steps:

(1) weighing a proper amount of AlON powder, putting the AlON powder into a phosphoric acid solution with the concentration of 0.5-3 wt.%, magnetically stirring for 10-30min at normal temperature, centrifugally filtering and drying to obtain hydrolysis-resistant hydrophilic AlON powder, wherein the mass ratio of the AlON powder to the phosphoric acid solution is 1: 2-20;

(2) mixing the AlON powder obtained in the step (1) with deionized water and a dispersing agent, and performing ultrasonic dispersion for 10-30min to obtain a highly dispersed suspension, wherein the mass ratio of AlON to deionized water is 1: 3;

(3) weighing nitrate of M ions, dissolving the nitrate in deionized water to obtain a solution A, and pouring the solution A into the suspension obtained in the step (2) to form a suspension B, wherein the mass ratio of AlON in the suspension B to deionized water is 1: 3-10;

(4) preparing 0.002-0.2 mol/l of precipitator solution C, dropwise adding the precipitator solution C into the suspension B at the speed of 1-10ml/min, violently stirring in the dropwise adding process until the PH value reaches a set value or the precipitator is excessive, and then continuously stirring for 1-4h, carrying out centrifugal washing and drying to obtain AlON powder uniformly coated with M ions;

(5) forming the AlON powder obtained in the step (4), and removing glue in the air at 650 ℃ for 1-10h to obtain an AlON biscuit;

(6) placing the AlON biscuit obtained in the step (5) in N₂Sintering at high temperature of 1780 and 1950 ℃ in the atmosphere, preserving the heat for 1-12h, cooling along with the furnace, grinding and polishing to obtain the AlON transparent ceramic.

According to the scheme, the molecular formula of AlON in the step (1) is Al_(64+3)/xO_32-xN_xWherein x is more than or equal to 2.5 and less than or equal to 5, and the average particle size of the powder is less than 3 mu m.

According to the scheme, the dispersing agent in the step (2) is one of PEG2000, ammonium polyacrylate and ammonium polymethacrylate, and the content of the dispersing agent accounts for 0.1-2 wt% of the AlON powder.

According to the scheme, M ions in the step (3) are Mg²⁺、Ca²⁺、Sr²⁺、Ba²⁺、Mn²⁺、Sc³⁺、 Y³⁺、La³⁺、Ce³⁺、Eu³⁺、Pr³⁺、Sm³⁺、Gd³⁺、Tb³⁺、Dy³⁺、Ho³⁺、Er³⁺、Tm³⁺、Yb³⁺、Lu³⁺、 Zr⁴⁺One or more nitrate with purity higher than 99% and oxide mass converted from nitrate is 0.04-0.7 wt.% of AlON powder.

According to the scheme, the solution C in the step (4) is one of ammonia water, ammonium carbonate and ammonium phosphate solution.

According to the scheme, the forming in the step (5) is one of dry pressing, slip casting and gel injection molding, wherein cold isostatic pressing is required after dry pressing is adopted.

According to the scheme, the sintering in the step (6) is one of pressureless sintering, hot-pressing sintering and spark plasma sintering, or one of the sintering and the hot isostatic pressing sintering are combined for use.

The principle of the invention is as follows: in order to prepare AlON suspension liquid taking deionized water as a dispersion medium, firstly, phosphoric acid hydrolysis resistance treatment is carried out on AlON powder, then, based on the non-uniform nucleation theory, a chemical precipitation method is adopted, and the thickness and chemical components of a uniform coating layer are accurately regulated and controlled by adjusting the concentration of a sintering aid or an activated ion and the dropping rate of a precipitator solution, so that a compact precursor which can be decomposed into the sintering aid or an activator is uniformly deposited on the surface of AlON particles. The uniformly distributed sintering aid or activator can effectively avoid differential sintering in the sintering process, inhibit the formation of crystal pores and reduce the formation of a second phase caused by over-fast growth of local crystal grains.

The beneficial results of the invention are:

1. the method adopts a chemical precipitation method to uniformly coat AlON powder, takes deionized water as a dispersion medium, is healthy and environment-friendly, and has strong operability; 2. the prepared AlON ceramic has high transparency, fine crystal grains, small internal stress and high strength; 3. the sintering temperature of the AlON transparent ceramic is relatively low, and the time is short; 4. the prepared AlON fluorescent transparent ceramic has high quenching concentration and high luminous efficiency; 5. the method has simple process and strong repeatability, and is beneficial to preparing large-size transparent ceramics.

Drawings

FIG. 1 is a scanning electron micrograph of AlON transparent ceramic prepared in example 1 of the present invention.

FIG. 2 is a graph showing the in-line transmittance of AlON transparent ceramic obtained in example 1 of the present invention.

FIG. 3 is a photograph of an AlON transparent ceramic prepared in example 1 of the present invention.

Detailed Description

For a better understanding of the present invention, the contents of the present invention will be further explained below with reference to the drawings and examples, but the contents of the present invention are not limited to the following examples.

Example 1:

weighing 10g of self-made AlON powder, adding the self-made AlON powder into 200g of phosphoric acid solution with the concentration of 0.5 wt.%, magnetically stirring for 10 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blowing at 40 ℃ for 24 hours. Drying the powderMixing the mixture with 30g deionized water and 0.01 g dispersant ammonium polymethacrylate, magnetically stirring, and adding 0.07gY₂O₃Y (NO) of₃)₃And (3) keeping the mass ratio of the AlON powder to the deionized water to be 1: 10. Then 0.2mol/l ammonia solution is added dropwise at a rate of 10ml/min to the vigorously stirred suspension, the dropwise addition is stopped when the pH is 9.2, and stirring is continued for 2h to ensure complete precipitation. The suspension was washed 3 times by centrifugal filtration at 3000r/min and dried at 70 ℃ for 24 hours. Taking a proper amount of dried AlON powder, adding PVA (polyvinyl alcohol) with the mass of 1 wt.% of the AlON powder for granulation, performing dry pressing at 20MPa to form a biscuit, performing cold isostatic pressing at 200MPa, and discharging glue in air at 650 ℃ for 5 hours. At 0.1MPa N₂Under protection, the temperature is raised to 1880 ℃ at the heating rate of 10 ℃/min, pressureless sintering is carried out for 12h, and furnace cooling is carried out. And cutting, grinding and polishing the cooled sintered body to obtain the AlON structure transparent ceramic.

The AlON transparent ceramic obtained in this example was subjected to SEM test (see fig. 1), and fig. 1 illustrates: the prepared material is mainly isometric crystal, the average grain size is about 102 mu m, and almost no air holes exist.

The transmittance test was performed (see fig. 2), fig. 2 illustrates: the linear transmittance of a sample with the thickness of 4mm at 600nm measured by an ultraviolet-visible spectrophotometer is 77%. The microhardness is 16.2GPa and the fracture toughness is 2.3 MPa.m measured by an indentation method^{1 /2}。

Example 2:

weighing 20g of self-made AlON powder, adding 40g of phosphoric acid solution with the concentration of 3 wt.%, magnetically stirring for 30 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blast at 40 ℃ for 24 hours. Mixing the dried powder with 60g deionized water and 0.4g dispersant PEG2000, magnetically stirring, and adding 0.04gY₂O₃And 0.16g La₂O₃Y (NO) of₃)₃And La (NO)₃)₃And mixing the solution, wherein the mass ratio of the final AlON powder to the deionized water is 1: 10. Then 0.002mol/l ammonia solution was added dropwise at a rate of 1ml/min to the vigorously stirred suspension, the dropwise addition was stopped at a pH of 9.1 and stirring was continued for 4h to ensure complete precipitation. The suspension was brought to 3000r/min, washing by centrifugal filtration 3 times, and drying at 70 ℃ for 24 hours. Taking 10g of dried AlON powder, 15g of deionized water, 0.3g of monomer acrylamide, 0.03g of cross-linking agent N, N' -methylene acrylamide and 0.2g of dispersing agent PEG20000.2g, and magnetically stirring for 2 h. And (3) degassing the obtained slurry in vacuum, adding 0.03g of initiator ammonium persulfate, uniformly stirring, pouring into a mould, and curing for 3 hours at 70 ℃. The demoulded biscuit is dried for 2 days at 50 ℃ and then is subjected to gel removal in air at 650 ℃ for 10 hours. At 0.1MPaN₂Under protection, the temperature is raised to 1800 ℃ at the heating rate of 10 ℃/min, pressureless sintering is carried out for 2h, hot isostatic pressing is carried out for 4h at 1850 ℃, and the pressure is 200 MPa. And cutting, grinding and polishing the cooled sintered body to obtain the AlON structure transparent ceramic.

The ceramic sample having an average crystal grain size of 48 μm and a thickness of 4mm was measured to have a linear transmittance at 600nm of 81%, a microhardness of 16.4GPa, and a fracture toughness of 2.5MPa m^1/2。

Example 3:

weighing 20g of self-made AlON powder, adding the self-made AlON powder into 100g of phosphoric acid solution with the concentration of 1 wt.%, magnetically stirring for 10 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blowing at 40 ℃ for 24 hours. Mixing the dried powder with 80g deionized water and 0.1g dispersant ammonium polymethacrylate, magnetically stirring, and adding prepared Sr (NO) with the mass equivalent to 0.2g SrO₃)₂And (3) keeping the mass ratio of the AlON powder to the deionized water to be 1: 5. 0.1mol/l ammonium carbonate solution was then added dropwise at a rate of 5ml/min to the vigorously stirred suspension, the dropwise addition being stopped when the precipitant was in excess and stirring continued for 4 h. The suspension was washed 3 times by centrifugal filtration at 3000r/min and dried at 70 ℃ for 24 h. Taking 10g of dried AlON powder, 20g of deionized water and 0.1g of dispersant ammonium polymethacrylate, magnetically stirring for 2h, degassing in vacuum, and pouring porous Al₂O₃Drying in ceramic mold at room temperature for 24 hr, demolding, and drying at 60 deg.C for 24 hr to obtain biscuit of 0.1MPaN₂Pressureless sintering is carried out for 8h under the protection of 1920 ℃, and then furnace cooling is carried out. And cutting, grinding and polishing the cooled sintered body to obtain the AlON structure transparent ceramic.

The average grain size of the ceramic is 87 mu m, the straight-line transmittance at 600nm of a sample with the thickness of 4mm is 79 percent through measurement,the microhardness is 16.3GPa, the fracture toughness is 2.2 MPa.m^1/2。

Example 4:

weighing 20g of self-made AlON powder, adding the self-made AlON powder into 100g of phosphoric acid solution with the concentration of 2 wt.%, magnetically stirring for 10 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blowing at 40 ℃ for 24 hours. Mixing the dried powder with 100g deionized water and 0.1g dispersant ammonium polyacrylate, magnetically stirring, and adding 0.1g CaO-containing Ca (NO)₃)₂And (3) keeping the mass ratio of the AlON powder to the deionized water to be 1: 5. 0.1mol/l ammonium phosphate solution is then added dropwise at a dropping rate of 2ml/min to the vigorously stirred suspension, the dropwise addition being stopped when the precipitant is in excess and stirring is continued for 4 h. The suspension was washed 3 times by centrifugal filtration at 3000r/min and dried at 70 ℃ for 24 hours. Carbon is removed in air for 1h at 650 ℃. Taking appropriate amount of dried AlON powder at 0.1MPa N₂Hot-pressing and sintering at 1820 ℃ for 1h under the protection of 30MPa, and then cooling along with the furnace. And cutting, grinding and polishing the cooled sintered body to obtain the AlON structure transparent ceramic.

The ceramic sample having an average crystal grain size of 28 μm and a thickness of 4mm was measured to have a linear transmittance at 600nm of 71%, a microhardness of 16.2GPa, and a fracture toughness of 2.7 MPa-m^1/2。

Example 5:

weighing 20g of self-made AlON powder, adding 50g of phosphoric acid solution with the concentration of 1 wt.%, magnetically stirring for 20 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blowing at 40 ℃ for 24 hours. Mixing the dried powder with 60g deionized water and 0.3g dispersant PEG2000, magnetically stirring, and adding 0.004gEu₂O₃Eu (NO)₃)₃And (3) keeping the mass ratio of the AlON powder to the deionized water to be 1: 3. Then 0.2mol/l ammonia solution was added dropwise at a rate of 1ml/min to the vigorously stirred suspension, the dropwise addition was stopped at a pH of 9.3 and stirring was continued for 4h to ensure complete precipitation. The suspension was washed 3 times by centrifugal filtration at 3000r/min and dried at 70 ℃ for 24 hours. Taking a proper amount of dried AlON powder, dry-pressing into a biscuit at 20MPa, then carrying out cold isostatic pressing at 200MPa, and removing carbon in air at 650 ℃ for 1 h. At 0.1MPa N₂Under protection, the temperature is raised to 1950 ℃ at the heating rate of 15 ℃/min, pressureless sintering is carried out for 12 hours, and furnace cooling is carried out. And cutting, grinding and polishing the cooled sintered body to obtain the AlON fluorescent transparent ceramic.

The measurement shows that the ceramic block has an average grain size of 106 microns, the linear transmittance at 600nm of a sample with the thickness of 4mm is 72 percent, the peak wavelength of an emission spectrum is 490nm, the microhardness is 16.0GPa, and the fracture toughness is 2.1 MPa.m^1/2。

Example 6:

weighing 20g of self-made AlON powder, adding the self-made AlON powder into 100g of phosphoric acid solution with the concentration of 2 wt.%, magnetically stirring for 10 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blowing at 40 ℃ for 24 hours. Mixing the dried powder with 100g deionized water and 0.2g dispersant ammonium polyacrylate, magnetically stirring, and adding 0.1g MgO and 0.04g MnO Mg (NO)₃)₂And Mn (NO)₃)₂And mixing the solution, and finally keeping the mass ratio of the AlON powder to the deionized water at 1: 5. Then 0.01mol/l aqueous ammonia solution was added dropwise at a rate of 5ml/min to the vigorously stirred suspension, the dropwise addition was stopped at a pH of 9.3 and stirring was continued for 4 h. The suspension was washed 3 times by centrifugal filtration at 3000r/min and dried at 70 ℃ for 24 hours. Carbon is removed in air for 1h at 650 ℃. Taking appropriate amount of dried AlON powder at 0.1MPa N₂Under protection, the plasma is discharged at 1780 ℃ at the heating rate of 100 ℃/min for rapid sintering for 10min, and the pressure is 30 MPa. And cutting, grinding and polishing the cooled sintered body to obtain the AlON fluorescent transparent ceramic.

The ceramic sample with the average grain size of 7 mu m and the thickness of 4mm has the linear transmittance of 52 percent at 600nm, the peak wavelength of the emission spectrum of 512nm, the microhardness of 16.6GPa and the fracture toughness of 3.0 MPa-m^1/2。

Example 7:

weighing 20g of self-made AlON powder, adding the self-made AlON powder into 100g of phosphoric acid solution with the concentration of 2 wt.%, magnetically stirring for 10 minutes, centrifugally filtering at the speed of 3000r/min, and drying by air blowing at 40 ℃ for 24 hours. Mixing the dried powder with 100g deionized water and 0.2g dispersant ammonium polyacrylate, magnetically stirring, and adding 0.02gEr₂O₃And 0.03g Yb₂O₃Er (NO) of₃)₃And Yb (NO)₃)₃And mixing the solution, and finally keeping the mass ratio of the AlON powder to the deionized water at 1: 6. Then 0.01mol/l aqueous ammonia solution was added dropwise at a rate of 5ml/min to the vigorously stirred suspension, the dropwise addition was stopped at a pH of 9.3 and stirring was continued for 4 h. The suspension was washed 3 times by centrifugal filtration at 3000r/min and dried at 70 ℃ for 24 hours. Taking a proper amount of dried AlON powder, adding PVA (polyvinyl alcohol) with the mass of 1 wt.% of the AlON powder for granulation, performing dry pressing at 20MPa to form a biscuit, performing cold isostatic pressing at 200MPa, and discharging glue in air at 650 ℃ for 5 hours. At 0.1MPa N₂Under protection, the temperature is raised to 1900 ℃ at the heating rate of 10 ℃/min and pressureless sintering is carried out for 8h, and then furnace cooling is carried out. And cutting, grinding and polishing the cooled sintered body to obtain the AlON fluorescent transparent ceramic.

The ceramic was measured to have an average crystal grain size of 123 μm, a linear transmittance at 600nm of a 4mm thick sample of 63%, a peak wavelength of emission spectrum of 655nm under laser irradiation at 980nm, a microhardness of 15.9GPa, and a fracture toughness of 2.0 MPa-m^1/2。