CN116425531A - A kind of infrared transparent ceramic ink and its preparation and application - Google Patents

Abstract

The invention provides an infrared transparent ceramic ink and preparation and application thereof, wherein the infrared transparent ceramic ink is obtained by mixing a plurality of ceramic auxiliary agents with ceramic powder, dispersing, ball milling and mixing, and defoaming, wherein a 3D model of a device is freely designed by using computer aided design software according to a use scene, a data set is formed after slicing treatment and is transmitted to a printer, and then a ceramic blank is printed; by precisely controlling the ink proportion, printing parameters and the heat treatment process, the infrared transparent ceramic with excellent optical performance can be printed. The printed infrared transparent ceramic has high density and excellent mechanical property, and almost has no difference with the traditional cold isostatic pressing ceramic, thereby saving the preparation cost and the production efficiency of the infrared transparent ceramic to a great extent. The method solves the problems that the existing manufacturing method depends on a die for molding, the preparation period is long, the efficiency is low, and the infrared special-shaped optical device is difficult to mold.

Description

A kind of infrared transparent ceramic ink and its preparation and application

technical field

The invention belongs to the technical field of infrared transparent ceramic preparation, and in particular relates to an infrared transparent ceramic ink and its preparation and application, wherein the application is to prepare special-shaped infrared transparent ceramic devices by using additive manufacturing technology and infrared transparent ceramic ink.

Background technique

An important promising application of infrared transparent ceramics is infrared optics for harsh service environments, including infrared domes, sensor protection, and high repetition rate infrared lasers. These applications require materials that not only have high optical clarity, abrasion resistance, and strength, but also have good thermal stability and low optical emissivity at high temperatures. With the wide application of infrared ceramics in environmental protection, security, military industry, national defense, etc., traditional molding methods can only form simple flat geometric shapes, which is the main obstacle restricting the application of infrared ceramics.

Additive manufacturing (3D printing) is a powerful manufacturing method for fast, accurate and customized objects with complex geometries. The emergence of 3D printing technology has opened up completely new possibilities for the manufacture of complex-shaped objects in a fully digital manufacturing process. Utilizing the high plasticity and rheology of organic matter, combined with infrared ceramic powder to prepare infrared ceramic ink suitable for 3D printing, which is a key step in realizing 3D printing of infrared transparent ceramics.

However, on the one hand, there are no related literature reports for 3D printing infrared transparent ceramic ink and its preparation method; The curing properties of glue are applied to the rapid manufacturing process of ceramic materials, but this scheme cannot be directly used for the preparation of infrared transparent ceramics, because the curing agent and hydrogel added by this method will significantly affect the optical properties of infrared ceramics.

Another example is CN113372114A which discloses a zirconia ceramic material extruded 3D printing material preparation and printing method, which uses a variety of additives mixed with zirconia powder to prepare zirconia ceramic materials that can be applied to extruded 3D printing, but the In the scheme, it is necessary to use organosilicon materials as defoamers, which will cause the formation of the second phase inside the ceramics and affect the optical properties of infrared ceramics. In addition, this method uses a high content of organic matter, which is not conducive to the densification and sintering of ceramics, and the prepared The material is not infrared transparent and is used in structural materials such as dental.

Another example is CN107840656A, which discloses a method of 3D printing and gel injection molding composite zirconia all-ceramic teeth. This method uses 3D printing to prepare a mold suitable for tooth manufacturing. It is a mode of indirect 3D printing, which is different from traditional gel injection molding. Injection molding is not fundamentally different.

The invention can realize the infrared transparent ceramic ink with high solid phase content and excellent shear thinning behavior through the design of the ink components, and prepare the ceramic component with excellent infrared transmission performance through the design of the sintering system.

Contents of the invention

In view of the above problems, the present invention provides a method for direct additive manufacturing (3D printing) of infrared transparent ceramics, so as to improve the forming ability of infrared optical devices with complex structures.

The specific solution is as follows:

The invention provides a method for additive manufacturing of infrared transparent material ceramics. Compared with the prior art, the method has the advantages of: (1) no need to customize the mold according to the molding device; (2) the solid content of the printing ink reaches 50vol % above is almost the same as traditional cold isostatic pressing; (3) can design 3D models by computer, quickly print infrared optical devices used in different scenarios, and its free geometric design and molding greatly expands the infrared transparency of zirconia Application scenarios of ceramics.

Technical scheme of the present invention is realized like this:

On the one hand, the invention protects an infrared transparent ceramic ink, and the solid phase content of the ink is 50-55vol%.

In a preferred embodiment, the viscosity range of the ink protected by the present invention is: 700cP@1000s ^-1 -100000cP@5s ^-1 ; the shear thinning index of the ink is ≥0.894.

In a preferred embodiment, the average particle diameter of the mixed powder in the ink protected by the present invention is 0.39-0.42 microns.

In another aspect, the present invention also protects a preparation method of infrared transparent ceramic ink, comprising the following steps:

a) dissolving the dispersant in deionized water, adding a pH regulator to obtain an alkaline dispersion;

b) mixing the binder, the plasticizer, and the wetting agent uniformly to obtain a regulating solution;

c) adding the ceramic powder into the alkaline dispersion liquid in step a), and ultrasonically dispersing evenly, then adding the adjusting liquid, stirring with a ball mill, and vacuum defoaming until no bubbles emerge to obtain the ink.

In a preferred embodiment, the present invention also protects a preparation method of infrared transparent ceramic ink, the pH value of the alkaline dispersion in step a) is 7.5-10.5; the pH regulator is selected from ammonia water, twelve At least one of sodium alkylsulfonate, magnesium acetate, sodium hydrogen phosphate and sodium dihydrogen phosphate, carbonic acid and sodium bicarbonate.

In a preferred embodiment, the present invention also protects a method for preparing an infrared transparent ceramic ink, wherein the particle size of the ceramic powder in step c) is ≤100nm, and the purity is ≥99.99%; the ceramic powder is selected from zirconia, yttrium oxide , at least one of aluminum oxide and magnesium oxide.

In a preferred embodiment, the present invention also protects a preparation method of infrared transparent ceramic ink, the mass ratio of the dispersant, deionized water in step a) and the ceramic powder in step c) is 0.1-4:15 -17:100.

In a preferred embodiment, the present invention also protects a method for preparing an infrared transparent ceramic ink, wherein the dispersant is selected from at least one of ammonium citrate, diammonium citrate, polyacrylic acid, ammonium polyacrylate, and herring oil ;

In a preferred embodiment, the present invention also protects a preparation method of infrared transparent ceramic ink, the mass ratio of the binder, plasticizer, wetting agent in step b) to the ceramic powder in step c) is 0.1-1:0.1-1.5:0.1-1:100.

In a preferred embodiment, the present invention also protects a preparation method of infrared transparent ceramic ink, wherein the binder is selected from at least one of polyvinyl alcohol and xanthan gum, and the plasticizer is selected from polyethylene At least one of glycol, methylcellulose, hydroxypropylmethylcellulose, and carboxymethylcellulose, and the wetting agent is at least one of glycerin, butylene glycol, and hexylene glycol.

In a preferred embodiment, the present invention also protects a preparation method of infrared transparent ceramic ink, the ultrasonic dispersion frequency in step c) is 40-120kHz; the speed of the ball mill stirring is 250-289r/min; the The vacuum degree of vacuum defoaming is -100kPa to -80kPa.

In yet another aspect, the present invention also protects the infrared transparent ceramic ink prepared by any one of the above methods.

In a preferred embodiment, the present invention also protects the infrared transparent ceramic ink prepared by any one of the above methods, and the solid phase content of the ink is 50-55vol%.

In a preferred embodiment, the present invention also protects the infrared transparent ceramic ink prepared by any one of the above methods, and the shear thinning index of the ink is ≥0.894.

In still another aspect, the present invention also protects the infrared transparent ceramic prepared by using the above infrared transparent ceramic ink.

In a preferred embodiment, the present invention also protects infrared transparent ceramics, and the relative density of said infrared transparent ceramics is ≥99.94%

In a preferred embodiment, the present invention also protects infrared transparent ceramics, and the transmittance of said infrared transparent ceramics in the 3-5 μm infrared band is ≥71%.

In still another aspect, the present invention also protects a method for preparing the above-mentioned infrared transparent ceramics. The method includes: building a 3D model, and printing out the green body after slicing; pre-sintering the green body, hot isostatic pressing Ceramics are obtained after sintering and annealing.

In a preferred embodiment, the present invention also protects a method for preparing the above-mentioned infrared transparent ceramics, the pre-sintering is to raise the green body from room temperature to 100-150°C at a heating rate of 1-5°C/min and keep it warm for 6 -10h; then rise to 400-500°C at a rate of 0.5-1.5°C/min, and keep warm for 10-20h; continue to rise to 1200-1380°C at a rate of 0.1-3°C/min, and keep warm for 1-3h, Then cool down naturally to take out the pre-sintered body.

In a preferred embodiment, the present invention also protects a method for preparing the above-mentioned infrared transparent ceramic, and the relative density of the pre-sintered body is ≥98%.

In a preferred embodiment, the present invention also protects a method for preparing the above-mentioned infrared transparent ceramics. The hot isostatic pressing sintering is to raise the temperature of the pre-sintered body from room temperature to 1200-1200- 1250°C, pressure 200MPa, and heat preservation for 10h to obtain infrared transparent ceramics.

In a preferred embodiment, the present invention also protects a method for preparing the above-mentioned infrared transparent ceramics, and the relative density of the infrared transparent ceramics is ≥99.96%.

In a preferred embodiment, the present invention also protects a method for preparing the above-mentioned infrared transparent ceramics. The annealing is to raise the infrared transparent ceramics from room temperature to 1100-1650°C at 2-10°C/min under air pressure-free conditions. ℃, keep warm for 10-30h.

Description of drawings

Fig. 1 is the transparent infrared ceramic transmittance prepared by embodiment 2

Fig. 2 is the infrared transparent ceramic microstructure figure that embodiment 8 prepares

Detailed ways

In order to provide a more concise description, some quantitative expressions given herein are not modified by the term "about". It is to be understood that, whether or not the term "about" is explicitly used, each quantity given herein is intended to refer to the actual given value, and also to refer to what one of ordinary skill in the art could reasonably infer. Approximations to these given values include approximations to these given values that result from experimental and/or measurement conditions.

Below in conjunction with specific embodiment, to further illustrate the present invention. It is necessary to point out here that embodiment is only used to further illustrate the present invention, can not be interpreted as the limitation of protection scope of the present invention, those skilled in the art can make some non-essential improvements according to the content of the present invention above and adjust. The test methods for which specific conditions are not indicated in the following examples are generally in accordance with conventional conditions, or in accordance with the conditions suggested by the manufacturer. All percentages and parts are by weight unless otherwise indicated.

The source, title and specification of the experimental material or experimental instrument adopted in the embodiment of the present invention are shown in the table below:

The present invention will be further described below in conjunction with the examples, but the protection scope of the present invention should not be limited.

Example 1: Ink

Weigh 0.4g of ammonium citrate, dissolve 0.4g of polyacrylic acid in 10g of deionized water, add ammonia water dropwise to adjust the dispersion to pH ≈ 7.5, disperse 60g of 3Y-TZP powder in the alkaline dispersion, and use an ultrasonic crusher at 80kHz Crushed for 10 minutes, under continuous natural storage conditions in the air (temperature 25°C, humidity 50%, air pressure 1.01×10 ^-5 Pa), after continuing to stir for 12 hours, when the static sedimentation rate of the suspension was 5%, the premix was obtained;

Then add the conditioning solution obtained by mixing 0.25g polyvinyl alcohol, 0.125g polyethylene glycol and 0.8g glycerin, place it on a planetary ball mill, ball mill it at a speed of 250r/min for 12h to obtain ink, and place the ball milled ink in a vacuum In the defoaming machine, defoam under the condition of -80kPa for 5 minutes until no bubbles emerge from the ink, and the ink is obtained and set aside.

Test Example 1 Particle Size

Test sample: the ink that embodiment 1 prepares

Test equipment: Scanning electron microscope (Auriga S40, Zeiss, Oberkochen, Germany); Accelerating voltage: 3kV; Magnification: 100000 times; WD=6;

The average particle diameter of the mixed powder in the ink prepared in Example 1 is 0.41 microns.

Test Example 2: Rheological Properties Test

Test sample: the ink that embodiment 1 prepares

The rheological properties of ceramic inks were tested using a rotational rheometer (Anton Paar) with a parallel plate diameter of 20 mm. Viscosity was measured at 25 °C with a steady increase in shear rate from 0.1 to 1000 ^s using a solvent trap to reduce evaporation.

The viscosity of the ink prepared in Example 3 is 1356cP@10s ^-1 ; the shear thinning index of the ink is 0.912.

Example 2: Green body printing and sintering

According to the scene, use 3D modeling software to build a 3D model, and after the computer slices the 3D model, the data set is formed and sent to the 30system 3D printer produced by the American Hyrel company. Fill the ink prepared in Example 1 into the 3D printer, print out the ceramic green body, and set aside.

Green body sintering is divided into three steps, namely pre-sintering, hot isostatic pressing sintering and annealing.

The ceramic green body was raised from 30°C to 120°C at a heating rate of 1.5°C/min and kept for 6 hours, then raised to 450°C at a heating rate of 1°C/min and held for 20 hours; continued to rise at a heating rate of 1.5°C/min to 1300°C, and keep it warm for 3 hours; then cool down naturally to take out the pre-sintered body.

Hot isostatic pressing sintering further improved the density and optical properties of the ceramic body. The temperature was raised from room temperature to 1250 °C at a rate of 5 °C/min, the pressure was 200 MPa, and the temperature was kept for 10 h to obtain ceramic samples.

The annealing was carried out in a muffle furnace under the condition of no air pressure at 6°C/min from room temperature to 1100°C, and held for 30h to eliminate residual stress and oxygen vacancy defects, and obtain infrared transparent ceramics for future use.

Test Example 3: Relative Density Test

Test sample: the pre-sintered body prepared in embodiment 2, the ceramic sample prepared in embodiment 2;

The relative density was determined using the Archimedes method.

sample Relative density The pre-sintered body prepared in embodiment 2 98% The ceramic sample that embodiment 2 prepares 99.97%

The relative density of ceramics in the pre-sintering stage must exceed 92% in order to achieve final densification through HIP sintering. The relative density of the HIP sintered sample exceeds 99.9%. The sample has good infrared transmission performance and meets various requirements. Item Optical Application Conditions.

Example 3: Ink

Weigh and dissolve 0.4g ammonium polyacrylate and 0.4g diammonium citrate in 10g deionized water, add ammonia water dropwise to adjust the dispersion to pH ≈ 9.5, disperse 60g of yttrium oxide powder in the alkaline dispersion, and use ultrasonic crushing The machine was crushed at 80kHz for 10min, under the condition of continuous natural storage in the air condition (temperature 25°C, humidity 55%, air pressure 1.04×10 ^-5 Pa), after stirring for 12h, when the static sedimentation rate of the suspension was 6%, the premix was obtained;

Then add the conditioning solution obtained by mixing 0.25g xanthan gum, 0.125g hydroxypropyl methylcellulose and 0.8g glycerin, place it on a planetary ball mill, and ball mill it at a speed of 265r/min for 12h to obtain ink. The ink is placed in a vacuum defoamer, and defoamed at -90kPa for 5 minutes until no bubbles emerge from the ink, and the ink is obtained and set aside.

Test Example 4: Particle Size

Test sample: the ink that embodiment 3 prepares

Test equipment: Scanning electron microscope (Auriga S40, Zeiss, Oberkochen, Germany); Accelerating voltage: 3kV; Magnification: 100000 times; WD=6;

The average particle diameter of the mixed powder in the ink prepared in Example 3 is 0.39 microns.

Test Example 5: Rheological Properties Test

Test sample: the ink that embodiment 1 prepares

The rheological properties of ceramic inks were tested using a rotational rheometer (Anton Paar) with a parallel plate diameter of 20 mm. Viscosity was measured at 25 °C with a steady increase in shear rate from 0.1 to 1000 ^s using a solvent trap to reduce evaporation.

The viscosity of the ink prepared in Example 3 is 1310cP@10s ^-1 ; the shear thinning index of the ink is 0.932.

Example 4: Green body printing and sintering

According to the scene, use 3D modeling software to build a 3D model, and after the computer slices the 3D model, the data set is formed and sent to the 30system 3D printer produced by the American Hyrel company. Fill the ink prepared in Example 1 into the 3D printer, print out the ceramic green body, and set aside.

Green body sintering is divided into three steps, namely pre-sintering, hot isostatic pressing sintering and annealing.

Raise the ceramic green body from 30°C to 150°C at a heating rate of 3°C/min and keep it for 6 hours, then raise it to 400°C at a rate of 1°C/min, and keep it for 20 hours; continue to heat at a rate of 1.5°C/min to 1280°C and keep it warm for 3 hours; then cool down naturally to take out the pre-sintered body.

Hot isostatic pressing sintering further improved the density and optical properties of the ceramic body. The temperature was raised from room temperature to 1230 °C at a rate of 5 °C/min, the pressure was 200 MPa, and the temperature was kept for 10 h to obtain ceramic samples.

The annealing was carried out in a muffle furnace under the condition of no air pressure at 6°C/min from room temperature to 1100°C, and held for 30h to eliminate residual stress and oxygen vacancy defects, and obtain infrared transparent ceramics for future use.

Test Example 6: Relative Density Test

Test sample: the pre-sintered body prepared in embodiment 4, the ceramic sample prepared in embodiment 4;

The relative density was determined using the Archimedes method.

sample Relative density The pre-sintered body prepared in embodiment 4 98.4% The ceramic sample that embodiment 4 prepares 99.96%

The relative density of ceramics in the pre-sintering stage must exceed 92% in order to achieve final densification through HIP sintering. The relative density of the HIP sintered sample exceeds 99.9%. The sample has good infrared transmission performance and meets various requirements. Item Optical Application Conditions.

Embodiment 5: Ink

Weigh 0.4g of ammonium polyacrylate and dissolve it in 10g of deionized water, add ammonia water dropwise to adjust the pH of the dispersion to ≈11.5, and disperse 60g of yttrium oxide and magnesium oxide mixed powder (the volume ratio of yttrium oxide and magnesium oxide is 50:50) In the alkaline dispersion liquid, use an ultrasonic crusher at 80kHz to crush for 10 minutes, and then continue to stir for 12 hours under continuous natural storage conditions in the air (temperature 23°C, humidity 49%, air pressure 1.01×10 ^-5 Pa), and when the suspension When the static sedimentation rate is 3%, the premixed solution is obtained;

Then add the conditioning solution obtained by mixing 0.25g carboxymethylcellulose, 0.125g polyethylene glycol, 0.8g glycerin and 0.3g herring oil, place it on a planetary ball mill, and ball mill it at a speed of 265r/min for 12h to obtain ink. Place the ball-milled ink in a vacuum defoaming machine, and defoam it at -95kPa for 5 minutes until no bubbles emerge from the ink, and set it aside.

Test Example 7: Particle Size

Test sample: the ink that embodiment 5 prepares

Test equipment: Scanning electron microscope (Auriga S40, Zeiss, Oberkochen, Germany); Accelerating voltage: 3kV; Magnification: 100000 times; WD=6;

The average particle size of the mixed powder in the ink prepared in Example 5 is 0.42 microns.

Test Example 8: Rheological Properties Test

Test sample: the ink that embodiment 5 prepares

The rheological properties of ceramic inks were tested using a rotational rheometer (Anton Paar) with a parallel plate diameter of 20 mm. Viscosity was measured at 25 °C with a steady increase in shear rate from 0.1 to 1000 ^s using a solvent trap to reduce evaporation.

The viscosity of the ink prepared in Example 5 is 1100cP@10s ^-1 ; the shear thinning index of the ink is 0.904.

Example 6: Green body printing and sintering

According to the scene, use 3D modeling software to build a 3D model, and after the computer slices the 3D model, the data set is formed and sent to the 30system 3D printer produced by the American Hyrel company. Fill the ink prepared in Example 5 into the 3D printer, print out the ceramic green body, and set aside.

Green body sintering is divided into three steps, namely pre-sintering, hot isostatic pressing sintering and annealing.

The ceramic green body was raised from 30°C to 150°C at a heating rate of 5°C/min and held for 6 hours, then raised to 500°C at a heating rate of 1.5°C/min, kept for 20 hours, and continued at a heating rate of 3°C/min to 1200°C, and keep it warm for 3 hours; then cool down naturally to take out the pre-sintered body.

Hot isostatic pressing sintering further improved the density and optical properties of the ceramic body. The temperature was raised from room temperature to 1200 °C at a rate of 5 °C/min, the pressure was 200 MPa, and the temperature was kept for 10 h to obtain ceramic samples.

The annealing was carried out in a muffle furnace under the condition of no air pressure at 5°C/min from room temperature to 1100°C, and kept for 30h to eliminate residual stress and oxygen vacancy defects, and obtain infrared transparent ceramics for future use.

Test Example 9: Relative Density Test

Test sample: the pre-sintered body prepared in embodiment 6, the ceramic sample prepared in embodiment 6;

The relative density was determined using the Archimedes method.

sample Relative density The pre-sintered body prepared in embodiment 6 98.1% The ceramic sample that embodiment 6 prepares 99.94%

The relative density of ceramics in the pre-sintering stage must exceed 92% in order to achieve final densification through HIP sintering. The relative density of the HIP sintered sample exceeds 99.9%. The sample has good infrared transmission performance and meets various requirements. Item Optical Application Conditions.

Embodiment 7: Ink

Weigh 0.3g of ammonium citrate and dissolve it in 10g of deionized water, add ammonia water dropwise to adjust the dispersion to pH ≈ 9.5, disperse 60g of 3Y-TZP powder in the alkaline dispersion, and use an ultrasonic crusher at 80kHz to crush for 10min; Under continuous natural storage conditions (temperature 21°C, humidity 57%, air pressure 1.03×10 ^-5 Pa), after stirring for 12 hours, when the static sedimentation rate of the suspension is 4%, the premix is obtained;

Then add the conditioning solution obtained by mixing 0.25g carboxymethylcellulose, 0.125g methylcellulose, 0.8g glycerin and 0.3g herring oil, place it on a planetary ball mill, and ball mill it at a speed of 289r/min for 12h to obtain ink , place the ball-milled ink in a vacuum degassing machine, and degas it for 5 minutes under the condition of -85kPa until no bubbles float out of the ink, and set it aside.

Test Example 10: Particle Size

Test sample: the ink that embodiment 7 prepares

Test equipment: Scanning electron microscope (Auriga S40, Zeiss, Oberkochen, Germany); Accelerating voltage: 3kV; Magnification: 100000 times; WD=6;

The average particle diameter of the mixed powder in the ink prepared in Example 7 is 0.42 microns.

Test Example 11: Rheological Properties Test

Test sample: the ink that embodiment 7 prepares

The rheological properties of ceramic inks were tested using a rotational rheometer (Viscotester iQ Air, HAAKE) with a parallel plate diameter of 20 mm. Viscosity was measured at 25 °C with a steady increase in shear rate from 0.1 to 1000 ^s using a solvent trap to reduce evaporation.

The viscosity of the ink prepared in Example 7 is 700cP@1000s ^-1 ; the shear thinning index of the ink is 0.894.

Example 8: Green body printing and sintering

According to the scene, use 3D modeling software to build a 3D model, and after the computer slices the 3D model, the data set is formed and sent to the 30system 3D printer produced by the American Hyrel company. Fill the ink prepared in Example 7 into the 3D printer, print out the ceramic green body, and set aside.

Green body sintering is divided into three steps, namely pre-sintering, hot isostatic pressing sintering and annealing.

The ceramic green body was raised from 30°C to 150°C at a heating rate of 5°C/min and kept for 6 hours, then raised to 500°C at a heating rate of 1.5°C/min, and kept at 20 hours; continued to rise at a heating rate of 3°C/min to 1280°C, and keep it warm for 3 hours; then cool down naturally to take out the pre-sintered body.

The relative density of the sintered body is 98.6%.

Hot isostatic pressing sintering further improved the density and optical properties of the ceramic body. The temperature was raised from room temperature to 1250 °C at a rate of 5 °C/min, the pressure was 200 MPa, and the temperature was kept for 10 h to obtain ceramic samples. The relative density of the sintered body is 99.96%.

The annealing was carried out in a muffle furnace under the condition of no air pressure at 6°C/min from room temperature to 1100°C, and held for 30h to eliminate residual stress and oxygen vacancy defects, and obtain infrared transparent ceramics for future use.

Test Example 12: Relative Density Test

Test sample: the pre-sintered body prepared in embodiment 8, the ceramic sample prepared in embodiment 8;

The relative density was determined using the Archimedes method.

sample Relative density The pre-sintered body prepared in embodiment 8 98.6% The ceramic sample that embodiment 8 prepares 99.96%

The relative density of ceramics in the pre-sintering stage must exceed 92% in order to achieve final densification through HIP sintering. The relative density of the HIP sintered sample exceeds 99.9%. The sample has good infrared transmission performance and meets various requirements. Item Optical Application Conditions.

Test Example 13: Transmittance Test

Test sample: the transparent infrared ceramic prepared in Example 2;

Test equipment: Fourier transform infrared spectrometer (Bruker, VERTEX 70, Germany);

Test method: measure the online transmittance of the sample in the wavelength range of 2.5-8μm;

As shown in FIG. 1 , in the 3-5 μm infrared band, the peak infrared transmittance of the transparent infrared ceramic prepared in Example 2 is about 71%. Meet the practical application of infrared optical components. This verifies the feasibility of using 3D printing to manufacture transparent ceramics.

Test Example 14: Electron Microscope

Test sample: transparent infrared ceramics prepared in Example 8;

Test equipment: scanning electron microscope (Auriga S40, Zeiss, Oberkochen, Germany); accelerating voltage: 1.5kV; magnification: 80000 times; WD=4.9;

As shown in Figure 2, the crystal grains of the transparent infrared ceramic sample prepared in Example 8 are densely packed, indicating that the densification is successful, the grain size is about 200±30nm, and the grain boundaries are clean, which is conducive to the improvement of the optical performance of the ceramic sample.

Claims (23)

1. An infrared transparent ceramic ink, characterized in that the ink has a solid phase content of 50-55vol%.

2. The ink of claim 1, wherein the ink has a viscosity in the range of: 700cP@1000s ^-1 -100000cP@5s ^-1 The shear thinning index of the ink is more than or equal to 0.894.

3. The ink of claim 1, wherein the average particle size of the mixed powder in the ink is 0.39 to 0.42 microns.

4. The preparation method of the infrared transparent ceramic ink is characterized by comprising the following steps of:

a) Dissolving a dispersing agent in deionized water, and adding a PH regulator to obtain an alkaline dispersion;

b) Uniformly mixing a binder, a plasticizer and a wetting agent to obtain a regulating solution;

c) Adding ceramic powder into the alkaline dispersion liquid in the step a), uniformly dispersing by ultrasonic, then adding a regulating liquid, ball milling and stirring, and vacuum defoaming until no bubbles are floated out, thus obtaining the ink.

5. The process according to claim 4, wherein the pH of the alkaline dispersion in step a) is from 7.5 to 10.5; the pH regulator is at least one selected from ammonia water, sodium dodecyl sulfonate, magnesium acetate, sodium hydrogen phosphate and sodium dihydrogen phosphate, carbonic acid and sodium bicarbonate.

6. The method of claim 4, wherein the ceramic powder in step c) has a particle size of 100nm or less and a purity of 99.99% or more; the ceramic powder is at least one selected from zirconia, yttria, alumina and magnesia.

7. The method of claim 4, wherein the mass ratio of dispersant, deionized water in step a) to ceramic powder in step c) is 0.1-4:15-17:100.

8. The method of claim 7, wherein the dispersant is selected from at least one of ammonium citrate, diammonium citrate, polyacrylic acid, ammonium polyacrylate, and herring oil.

9. The method of claim 4, wherein the mass ratio of the binder, plasticizer, wetting agent in step b) to the ceramic powder in step c) is 0.1-1:0.1-1.5:0.1-1:100.

10. The method according to claim 9, wherein the binder is at least one selected from polyvinyl alcohol and xanthan gum, the plasticizer is at least one selected from polyethylene glycol, methylcellulose, hydroxypropyl methylcellulose and carboxymethyl cellulose, and the wetting agent is at least one selected from glycerin, butanediol and hexanediol.

11. The method of claim 4, wherein the ultrasonic dispersion frequency in step c) is 40 to 120kHz; the ball milling and stirring speed is 250-289r/min; the vacuum degree of the vacuum defoamation is-100 kPa to-80 kPa.

12. An infrared transparent ceramic ink prepared by the method of any one of claims 4-11.

13. The ink of claim 12, wherein the ink has a solid content of 50 to 55vol%.

14. The ink of claim 13, wherein the ink has a shear thinning index of greater than or equal to 0.894.

15. An infrared transparent ceramic prepared using the ink of claim 1 or 12.

16. The infrared transparent ceramic of claim 15, wherein the infrared transparent ceramic has a relative density of greater than or equal to 99.94%.

17. The infrared transparent ceramic of claim 15, wherein the infrared transparent ceramic has a transmittance of greater than or equal to 71% in the infrared band of 3-5 μm.

18. A method of making the infrared transparent ceramic of claim 15, the method comprising: establishing a 3D model, and printing out a blank after slicing; and (3) pre-sintering the blank, sintering by hot isostatic pressing and annealing to obtain the ceramic.

19. The method of claim 18, wherein the pre-sintering is to heat the green body from room temperature to 100-150 ℃ for 6-10 hours at a heating rate of 1-5 ℃/min; then raising the temperature to 400-500 ℃ at a heating rate of 0.5-1.5 ℃/min, and preserving the temperature for 10-20h; continuously raising the temperature to 1200-1380 ℃ at the speed of 0.1-3 ℃/min, preserving the heat for 1-3h, and then naturally cooling to take out the pre-sintered body.

20. The method of claim 19, wherein the relative density of the pre-sintered body is greater than or equal to 98%.

21. The method of claim 19, wherein the hot isostatic pressing sintering is performed by heating the pre-sintered body from room temperature to 1200-1250 ℃ at a heating rate of 5-6 ℃/min, and maintaining the pressure at 200MPa for 10 hours to obtain the infrared transparent ceramic.

22. The method of claim 21, wherein the infrared transparent ceramic has a relative density of 99.96% or greater.

23. The method of claim 21, wherein the annealing is performed by heating the infrared transparent ceramic from room temperature to 1100-1650 ℃ at 2-10 ℃/min under air non-pressure conditions, and maintaining the temperature for 10-30 hours.

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