CN111825432A

CN111825432A - Fine-grain pink ZTA ceramic and preparation method thereof

Info

Publication number: CN111825432A
Application number: CN202010757028.5A
Authority: CN
Inventors: 熊慧文; 雷鹏飞; 陈超; 胡懿郃; 周科朝
Original assignee: Xiangya Hospital of Central South University
Current assignee: Xiangya Hospital of Central South University
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2020-10-27

Abstract

The invention discloses a preparation method of fine-grain pink ZTA ceramic, which comprises the steps of mixing aluminum oxide, yttrium oxide stabilized zirconia, carbonic acid and a chromium source to obtain mixed powder, adding the mixed powder into an alkaline solution containing an anionic dispersant to obtain a mixture, adding an adhesive into the mixture, carrying out ball milling to obtain ceramic slurry, carrying out spray granulation and drying on the obtained ceramic slurry to obtain ZTA composite powder, carrying out compression molding on the ZTA composite powder to obtain a green body, placing the green body in an air atmosphere, carrying out primary sintering to obtain a primary blank, carrying out hot isostatic pressing sintering on the primary blank to obtain the ZTA ceramic material, wherein the temperature of the hot isostatic pressing sintering is 20-50 ℃ lower than the temperature of the primary sintering. The fine-grain ZTA ceramic obtained by the preparation method has high hardness, toughness, wear resistance and biocompatibility, and can be widely applied to cutting tools, structural ceramics, human body wear-resistant implant materials and the like.

Description

Fine-grain pink ZTA ceramic and preparation method thereof

Technical Field

The invention belongs to the technical field of ceramic material preparation, and particularly relates to fine-grain pink ZTA ceramic and a preparation method thereof.

Background

The Zirconia Toughened Alumina (ZTA) ceramic has higher obdurability than alumina and more excellent hardness and wear resistance than zirconia, thereby being a complex phase ceramic material with high strength, high hardness and good toughness. Pink ZTA is a ceramic developed based on ZTA ceramic, which is toughened by the transformation of zirconium oxide, and is prepared by introducing appropriate amounts of strontium oxide, calcium oxide and magnesium oxide, and reacting with aluminum oxide to form SA6 (SrO.6Al)₂O₃)，CA6(CaO·6Al₂O₃) Or MA6 (MgO.6Al)₂O₃) (ii) a The component forms plate-shaped alumina crystal grains in a microstructure, can further induce crack deflection, and improves the toughness of the ceramic. The pink appearance is formed by introducing a small amount of chromium oxide which is dissolved in aluminum oxide to induce the color change, and simultaneously, the wear resistance of the ZTA ceramic can be improved. At present, pink ZTA obtained by the conventional powder metallurgy preparation method has the following problems: (1) the superfine zirconia and alumina powder are unevenly distributed in the ball milling process, so that single-phase grains are directly contacted and combined to grow, and the grains in the final sintered structure are coarse; (2) compact structure needs to be formed at higher temperature, so that the growth of ceramic grains is easily accelerated, and the comprehensive performance of the material is reduced; (3) the zirconia or coarse zirconia in contact with each other is easy to generate aging phase transformation or stress phase transformation, and microcracks are generated to reduce the toughness of the material.

Disclosure of Invention

In order to solve the problems of grain growth caused by uneven tissue distribution of pink ZTA ceramic and crack generation of ceramic due to aging or stress induced phase change in the prior art, the invention aims to provide the fine-grain pink ZTA ceramic and the preparation method thereof.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

the invention relates to a preparation method of fine-grain pink ZTA ceramic, which comprises the following steps:

step one preparation of ceramic slurry

Mixing alumina, yttria-stabilized zirconia, carbonic acid and a chromium source to obtain mixed powder, adding the mixed powder into an alkaline solution containing an anionic dispersant to obtain a mixture, adding an adhesive into the mixture, performing ball milling to obtain ceramic slurry,

step two preparation of Green bodies

Spray granulating and drying the ceramic slurry obtained in the step one to obtain ZTA composite powder, then pressing and forming the ZTA composite powder to obtain a green body,

step three sintering and forming

And (3) placing the green body obtained in the step (II) in an air atmosphere, performing primary sintering to obtain a primary blank, and performing hot isostatic pressing sintering on the primary blank to obtain the ZTA ceramic material, wherein the hot isostatic pressing sintering temperature is 20-50 ℃ lower than the primary sintering temperature.

According to the invention, firstly, carbonic acid is introduced into the raw materials to improve the dispersion performance of the slurry, and meanwhile, in the wet ball milling process of the raw materials, alkaline water is used as a ball milling medium, and a proper amount of anionic dispersant is introduced, so that the superfine ceramic slurry with good dispersibility, stability and low viscosity is obtained by ball milling. Then, on the basis of the ceramic slurry, spray granulation and drying are carried out to obtain ZTA composite powder with good fluidity, after compression molding, sintering is carried out at a higher temperature to obtain a primary blank, then the temperature is reduced, and static sintering such as heating and the like is carried out, so that not only can the fine crystal grains of the product be ensured, but also residual pores are gradually eliminated under the action of external force, and the high-performance pink ZTA ceramic material with fine crystal grains and high density is obtained.

In the preferred scheme, in the first step, the mixed powder comprises, by mass, 65-80 parts of alumina, 20-30 parts of yttria-stabilized zirconia, 0.5-3.0 parts of carbonic acid and 0.2-0.8 part of a chromium source.

Further preferably, the carbonate is at least one selected from strontium carbonate, calcium carbonate, and magnesium carbonate.

Further preferably, the chromium source is selected from chromium oxide or yttrium chromate.

In the present invention, when the chromium source is yttrium chromate, the mass part of the chromium source in the mixed powder is converted into the mass of chromium trioxide.

Preferably, the particle size of the alumina is 0.10-0.30 μm, preferably 0.18-0.22 μm.

Preferably, the particle size of the yttria-stabilized zirconia is 0.02-0.15 μm, and preferably 0.05-0.10 μm.

Preferably, the particle size of the chromium sesquioxide is 0.1-1.0 μm, and preferably 0.2-0.5 μm.

Preferably, in the first step, the preparation method of the alkaline solution containing the anionic dispersant comprises the following steps: adjusting the pH value of water to 9-11, and then adding an anionic dispersant, wherein the addition amount of the anionic dispersant is 0.2-1.0% of the mass of the mixed powder, and preferably 0.5-0.8%.

Further preferably, ammonia water is added to adjust the pH of the water to 9-11.

Further preferably, the anionic dispersant is selected from ammonium polyacrylate or diammonium citrate.

In a preferable scheme, in the first step, the volume fraction of the mixed powder in the mixture is 25-40%, and preferably 30-35%.

Preferably, in the first step, the adding amount of the adhesive is 1-3% of the mass of the mixed powder.

Further preferably, the binder is selected from polyvinyl alcohol.

Preferably, in the step one, the ball milling time is 30-60 h.

Preferably, in the second step, the particle size of the ZTA composite powder is 8-15 μm, preferably 10-12 μm.

In the invention, the ZTA composite powder with good fluidity is obtained by adopting spray granulation and drying

Preferably, in the second step, the compression molding is performed by cold isostatic pressing, or is performed by performing die pressing and then performing cold isostatic pressing. By means of press forming, a ZTA pressed green compact with high density and uniformity is obtained.

In the preferable scheme, in the third step, the primary sintering temperature is 1450-1520 ℃, preferably 1480-1500 ℃, and the primary sintering time is 2-5 h

In the preferred scheme, in the third step, the density of the primary blank is 94-98%.

Preferably, in the third step, the pressure of the hot isostatic pressing sintering is 50-200 MPa, preferably 100-150 MPa, and the time of the hot isostatic pressing sintering is 1-3 h.

The invention also provides the ZTA ceramic material prepared by the preparation method.

The ZTA ceramic material has an alumina average particle size of 0.4-0.8 μm, a zirconia average particle size of 0.2-0.5 μm, and the zirconia is uniformly dispersed around the alumina grains, and the contact ratio of the zirconia grain boundary is less than 5%.

The density of the ZTA ceramic material is more than or equal to 99 percent.

Principles and advantages

According to the invention, on one hand, through the design of a ceramic slurry system and on the other hand, through skillfully constructing a sintering program, pink ZTA ceramic with uniform two-phase distribution, fine crystal grains and high density is finally obtained, so that the ceramic material has high performance.

Under the condition of a certain solid content, a low-viscosity and stable slurry suspension is a prerequisite for obtaining a high-uniformity mixed material, however, the interparticle interaction force of nano or ultrafine powder is large, and the nano or ultrafine powder is not easy to disperse, and the inventor finds that a commonly used plate crystal additive phase such as strontium oxide, calcium oxide or magnesium oxide can be hydrolyzed with water even if a small amount of the commonly used plate crystal additive phase is added, so that the dispersion effect of a dispersing agent on alumina and zirconia particles is greatly reduced. Based on this, the inventor adds the superfine ZTA mixed powder suspension with better dispersion effect into ZTA in the form of strontium carbonate, magnesium carbonate or calcium carbonate; and meanwhile, a proper amount of anionic dispersing agent, especially ammonium polyacrylate or diammonium citrate is introduced, so that the slurry becomes very stable and has lower viscosity under the alkaline condition, and the method is very suitable for preparing superfine ZTA composite powder slurry.

The sintering activity of the ultrafine powder is high, and the sintering needs to be carried out at a lower temperature to obtain a high-density ZTA ceramic. Therefore, the other key point of the invention is that a high-activity powder compact is subjected to a certain temperature to obtain a primary blank with the density of 94-98%, and finally the primary blank is subjected to final full-dense sintering in an environment with hot isostatic pressing and the temperature lower than that of the primary sintering, so that the fine crystal grains of the product can be ensured, and simultaneously, residual pores are gradually eliminated under the action of external force.

Overall, compared with the traditional preparation method of fine grain ZTA ceramics, the invention adopts optimized raw material powder components, content and grain size, ball milling medium, thus obtaining the ultra-fine powder slurry suspension with low viscosity and stability, then obtaining green compact through subsequent granulation and cold isostatic pressing, and then obtaining the pink ZTA ceramics with high density and fine grains by combining air atmosphere sintering and subsequent hot isostatic pressing sintering with lower temperature. The ZTA ceramic prepared by the method has the following effects:

(1) the fine zirconia is dispersed around the alumina, and the two phases are mutually drawn, so that the grain size can be further refined, and the hardness and the wear resistance of the ZTA ceramic are effectively improved;

(2) the fine zirconia can ensure that the ceramic is relatively stable in the service process, the zirconia is not easy to have aging or stress induced phase change under relatively small stress and a humid environment, the microcracks of the ceramic are reduced, and the performance is more stable;

(3) by introducing carbonic acid, the precipitation of in-situ plate-shaped alumina is induced, and the strength and toughness of the fine-grain ZTA ceramic are further improved.

The ceramic material obtained by the invention has high hardness (Hv 5-1650-1850 Kgf/mm)²) Good bending resistance (sigma b is 800-1300 MPa) and better fracture toughness (Kic is 4-9 MPa-m)^-1/2). Therefore, the preparation method of the fine-grain pink ZTA ceramic can obviously improve the tissue distribution of the ZTA ceramic, effectively improve the mechanical strength and toughness of the ZTA ceramic, and can be widely applied to cutting tools, structural ceramics and peopleBody abrasion resistant implant materials, and the like.

Drawings

FIG. 1 is a SEM image (a) of the macroscopic morphology (a) and the fractures (b) of a pink ZTA ceramic sample prepared in example 2.

FIG. 2 is a SEM image of a fracture of a ZTA ceramic prepared by the conventional method in comparative example 1.

Detailed Description

Example 1

The raw material powder used in this example includes 68 parts by weight of alumina, 30 parts by weight of 2 mol yttria-stabilized zirconia (2YSZ), 1.8 parts by weight of strontium carbonate, and 0.3 parts by weight of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.30 μm, the average grain size of the 2YSZ is 0.08 μm, and the average grain size of the chromium oxide powder is 0.70 μm. The preparation method of this example comprises the following steps:

(1) preparation of ZTA slurry. Adding a proper amount of ammonia water to adjust the pH value of the water to be 9.5; adding ammonium polyacrylate accounting for 0.6 percent of the total powder weight; then adding raw material powder into a ball milling medium, so that the volume of the raw material powder accounts for 35% of the total volume of water and the powder, and then adding polyvinyl alcohol accounting for 3% of the weight of the raw material powder; after ball milling for 60 hours, the low-viscosity ZTA ceramic slurry can be obtained.

(2) Spray drying was used to obtain spherical powder with a particle size of 12 μm.

(3) And (3) pressing the powder by adopting isostatic cool pressing to obtain a green compact, wherein the pressing pressure is 180MPa, the pressure maintaining time is 60s, and the density of the obtained green compact is 57%.

(4) And sintering the pressed blank in an air atmosphere, wherein the sintering temperature is 1490 ℃, the heat preservation time is 4h, and the density of the sintered primary blank is 96%.

(5) And (3) carrying out hot isostatic pressing sintering on the sintered primary blank, wherein the sintering temperature is 1460 ℃, the heat preservation time is 2 hours, and the density of the finally obtained pink ZTA ceramic is 99%.

The ZTA ceramic alumina obtained in example 1 had an average particle size of 0.68 μm and the zirconia had an average particle size of 0.35 μm, and the zirconia was uniformly distributed around the alumina crystal grains without agglomeration. The ZTA ceramic has a Vickers hardness Hv5 of 1670Kgf/mm²Bending strength of 1280MPa, fractureThe fracture toughness is 7.8 MPa.m^-1/2。

Example 2

The raw material powder used in this example includes, by weight, 74 parts of alumina, 24 parts of 3 mol yttria-stabilized zirconia (3YSZ), 0.7 parts of calcium carbonate, 0.5 parts of magnesium carbonate, and 0.5 parts of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.20 μm, the average grain size of the 3YSZ is 0.08 μm, and the average grain size of the chromium oxide powder is 0.50 μm. The preparation method of this example comprises the following steps:

(1) preparation of ZTA slurry: adding a proper amount of ammonia water to adjust the pH value of the water to be 9.5; adding diammonium citrate accounting for 0.4 percent of the total weight of the powder; then adding raw material powder into a ball milling medium, so that the volume of the raw material powder accounts for 30% of the total volume of water and the powder, and then adding polyvinyl alcohol accounting for 2% of the weight of the raw material powder; after ball milling for 48 hours, the low-viscosity ZTA ceramic slurry can be obtained.

(2) Spray drying was used to obtain spherical powder with a particle size of 10 μm.

(3) And (3) pressing the powder by adopting isostatic cool pressing to obtain a green compact, wherein the pressing pressure is 150MPa, the pressure maintaining time is 10s, and the density of the obtained green compact is 53%.

(4) Sintering and compacting in air atmosphere, wherein the sintering temperature is 1480 ℃, the heat preservation time is 4h, and the density of the sintered primary blank is 95%.

(5) And (3) carrying out hot isostatic pressing sintering on the sintered primary blank, wherein the sintering temperature is 1450 ℃, the heat preservation time is 2h, and the density of the finally obtained pink ZTA ceramic is 99%.

The ZTA ceramic alumina obtained in example 2 had an average particle size of 0.53 μm, the zirconia had an average particle size of 0.28. mu.m, and the zirconia was uniformly distributed around the alumina crystal grains without agglomeration. The ZTA ceramic has a Vickers hardness Hv5 of 1750Kgf/mm²Flexural strength of 1020MPa and fracture toughness of 6.3 MPa-m^-1/2。

Example 3

The raw material powder used in this example includes, by weight, 80 parts of alumina, 18 parts of yttria-stabilized zirconia (3YSZ) 3 moles, 1.5 parts of strontium carbonate, and 0.5 parts of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.25 μm, the average grain size of the 3YSZ is 0.15 μm, and the average grain size of the chromium oxide powder is 0.20 μm. The preparation method of this example comprises the following steps:

(1) preparation of ZTA slurry: adding a proper amount of ammonia water to adjust the pH value of the water to 10.5; adding ammonium polyacrylate accounting for 0.8 percent of the total weight of the powder; then adding raw material powder into a ball milling medium, so that the volume of the raw material powder accounts for 35% of the total volume of water and the powder, and then adding polyvinyl alcohol accounting for 2% of the weight of the raw material powder; after ball milling for 60 hours, the low-viscosity ZTA ceramic slurry can be obtained.

(3) And (3) pressing the powder by adopting isostatic cool pressing to obtain a green body, wherein the pressing pressure is 150MPa, the pressure maintaining time is 10s, and the density of the obtained green body is 55%.

(4) And sintering the pressed blank in an air atmosphere, wherein the sintering temperature is 1510 ℃, the heat preservation time is 5h, and the density of the sintered primary blank is 97%.

(5) And (3) carrying out hot isostatic pressing sintering on the sintered primary blank, wherein the sintering temperature is 1480 ℃, the heat preservation time is 3h, and the density of the finally obtained pink ZTA ceramic is 99.8%.

The ZTA ceramic alumina obtained in example 3 had an average particle size of 0.61 μm, the zirconia had an average particle size of 0.33 μm, and the zirconia was uniformly distributed around the alumina crystal grains without agglomeration. The ZTA ceramic has Vickers hardness Hv5 of 1810Kgf/mm²Bending strength of 1080MPa, and fracture toughness of 5.9 MPa-m^-1/2。

Comparative example 1

The raw material powder used in this comparative example 1 comprises 75 parts by weight of alumina, 23 parts by weight of 3 moles yttria-stabilized zirconia (3YSZ), 0.7 parts by weight of strontium oxide and 0.5 parts by weight of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.20 μm, the average grain size of the 3YSZ is 0.08 μm, and the average grain size of the chromium oxide powder is 0.50 μm. The preparation method of this example comprises the following steps:

(6): preparation of ZTA slurry. Adding a proper amount of ammonia water to adjust the pH value of the water to be 9.5; adding diammonium citrate accounting for 0.4 percent of the total weight of the powder; then adding raw material powder into a ball milling medium, so that the volume of the raw material powder accounts for 30% of the total volume of water and the powder, and then adding polyvinyl alcohol accounting for 2% of the weight of the raw material powder; after ball milling for 50h, ZTA ceramic slurry was obtained, but there was a settling phenomenon.

(7) Spray drying was used to obtain spherical powder with a particle size of 10 μm.

(8) And (3) pressing the powder by adopting isostatic cool pressing to obtain a green compact, wherein the pressing pressure is 150MPa, the pressure maintaining time is 10s, and the density of the obtained green compact is 53%.

(9) Sintering and compacting in air atmosphere, wherein the sintering temperature is 1480 ℃, the heat preservation time is 4h, and the density of the sintered primary blank is 95%.

(10) And (3) carrying out hot isostatic pressing sintering on the sintered primary blank, wherein the sintering temperature is 1450 ℃, the heat preservation time is 2 hours, and the density of the finally obtained pink ZTA ceramic is 98.5%.

The ZTA ceramic alumina obtained in this comparative example 1 had an average particle size of 0.73 μm, the zirconia had an average particle size of 0.45 μm, and there was some degree of agglomeration of the zirconia. The ZTA ceramic has a Vickers hardness Hv5 of 1670Kgf/mm²Flexural strength of 930MPa and fracture toughness of 5.5 MPa-m^-1/2。

Comparative example 2

The raw material powder used in this comparative example 2 includes 68 parts by weight of alumina, 30 parts by weight of 2 mols yttria-stabilized zirconia (2YSZ), 1.8 parts by weight of strontium carbonate, and 0.3 parts by weight of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.30 μm, the average grain size of the 2YSZ is 0.08 μm, and the average grain size of the chromium oxide powder is 0.70 μm. The preparation method of this example comprises the following steps:

(11) preparation of ZTA slurry. Adding a proper amount of ammonia water to adjust the pH value of the water to be 9.5; adding ammonium polyacrylate accounting for 0.6 percent of the total powder weight; then adding raw material powder into a ball milling medium, so that the volume of the raw material powder accounts for 35% of the total volume of water and the powder, and then adding polyvinyl alcohol accounting for 3% of the weight of the raw material powder; after ball milling for 60 hours, the low-viscosity ZTA ceramic slurry can be obtained.

(12) Spray drying was used to obtain spherical powder with a particle size of 12 μm.

(13) And (3) pressing the powder by adopting isostatic cool pressing to obtain a green compact, wherein the pressing pressure is 180MPa, the pressure maintaining time is 60s, and the density of the obtained green compact is 57%.

(14) And sintering the pressed blank in an air atmosphere, wherein the sintering temperature is 1490 ℃, the heat preservation time is 4h, and the density of the sintered primary blank is 96%.

(15) And (3) carrying out hot isostatic pressing sintering on the sintered primary blank, wherein the sintering temperature is 1500 ℃, the heat preservation time is 2 hours, and the density of the finally obtained pink ZTA ceramic is 99.3%.

The ZTA ceramic alumina obtained in this comparative example 2 had an average particle size of 0.88 μm, the zirconia had an average particle size of 0.59. mu.m, and the zirconia was grown with a small amount of agglomeration. The ZTA ceramic has a Vickers hardness Hv5 of 1620Kgf/mm²Bending strength of 950MPa and fracture toughness of 4.6 MPa.m^-1/2。

Comparative example 3

The raw material powder used in this comparative example 3 comprises, by weight, 80 parts of alumina, 18 parts of 3 mol yttria-stabilized zirconia (3YSZ), 1.5 parts of strontium carbonate and 0.5 parts of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.25 μm, the average grain size of the 3YSZ is 0.15 μm, and the average grain size of the chromium oxide powder is 0.20 μm. The preparation method of this example comprises the following steps:

(4) And sintering the pressed blank in air atmosphere, wherein the sintering temperature is 1550 ℃, the heat preservation time is 3h, and the density of the sintered blank is 99%.

Average of ZTA ceramic aluminas obtained in this comparative example 3The grain size was 1.2 μm, and the average grain size of zirconia was 0.85 μm, and it was found that the ceramic grains grew, but the zirconia was uniformly distributed around the alumina grains without agglomeration. The ZTA ceramic has a Vickers hardness Hv5 of 1650Kgf/mm²Flexural strength of 760MPa and fracture toughness of 4.2 MPa-m^-1/2。

Comparative example 4

The raw material powder used in this comparative example 4 comprises, by weight, 80 parts of alumina, 18 parts of 3 mol yttria-stabilized zirconia (3YSZ), 1.5 parts of strontium carbonate and 0.5 parts of chromium sesquioxide. Wherein the average grain size of the alumina powder is 0.25 μm, the average grain size of the 3YSZ is 0.15 μm, and the average grain size of the chromium oxide powder is 0.20 μm. The preparation method of this example comprises the following steps:

(1) preparation of ZTA slurry: adding a proper amount of ammonia water to adjust the pH value of the water to 8.2; adding ammonium polyacrylate accounting for 2% of the total powder weight; then adding raw material powder into a ball milling medium, so that the volume of the raw material powder accounts for 35% of the total volume of water and the powder, and then adding polyvinyl alcohol accounting for 2% of the weight of the raw material powder; after ball milling for 60 hours, the ZTA ceramic slurry with higher viscosity can be obtained, and a certain sedimentation phenomenon exists.

(4) And sintering the pressed blank in an air atmosphere, wherein the sintering temperature is 1500 ℃, the heat preservation time is 3h, and the density of the sintered primary blank is 96%.

(5) And (3) carrying out hot isostatic pressing sintering on the sintered primary blank, wherein the sintering temperature is 1460 ℃, the heat preservation time is 3 hours, and the density of the finally obtained pink ZTA ceramic is 99.2%.

The ZTA ceramic alumina obtained in this comparative example 4 had an average particle diameter of 0.75 μm, the zirconia had an average particle diameter of 0.38 μm, and there was partial agglomeration of the zirconia. The ZTA ceramic has Vickers hardness Hv5 of 1730Kgf/mm²Bending strength of 860MPa and fracture toughness of 4.8 MPa-m^-1/2。

Claims

1. A preparation method of fine-grain pink ZTA ceramic is characterized by comprising the following steps:

step one preparation of ceramic slurry

step two preparation of Green bodies

step three sintering and forming

And (3) placing the green body obtained in the step (II) in an air atmosphere, performing primary sintering to obtain a primary blank, and performing hot isostatic pressing sintering on the primary blank to obtain the ZTA ceramic material, wherein the hot isostatic pressing sintering temperature is 20-50 ℃ lower than that of the primary sintering temperature.

2. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the first step, in the mixed powder, by mass, 65-80 parts of alumina, 20-30 parts of yttria-stabilized zirconia, 0.5-3.0 parts of carbonic acid and 0.2-0.8 part of a chromium source; the carbonate is selected from at least one of strontium carbonate, calcium carbonate and magnesium carbonate, and the chromium source is selected from chromium oxide or yttrium chromate.

3. The method of making a fine-grained pink ZTA ceramic according to claim 2, wherein: the particle size of the alumina is 0.10-0.30 μm, the particle size of the yttria-stabilized zirconia is 0.02-0.15 μm, and the particle size of the chromium sesquioxide is 0.1-1.0 μm.

4. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the first step, the preparation method of the alkaline solution containing the anionic dispersant comprises the following steps: adjusting the pH value of water to 9-11, and then adding an anionic dispersant, wherein the addition amount of the anionic dispersant is 0.2-1.0% of the mass of the mixed powder, and the anionic dispersant is selected from ammonium polyacrylate or diammonium citrate.

5. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the first step, the volume fraction of the mixed powder in the mixture is 25-40%.

6. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the first step, the adding amount of the adhesive is 1-3% of the mass of the mixed powder, and the adhesive is selected from polyvinyl alcohol.

7. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the first step, the ball milling time is 30-60 h.

8. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the second step, the particle size of the ZTA composite powder is 8-15 μm,

and in the second step, the compression molding mode is cold isostatic pressing, or mould pressing is carried out firstly and then cold isostatic pressing is carried out.

9. The method of making a fine-grained pink ZTA ceramic according to claim 1, wherein: in the third step, the temperature of the primary sintering is 1450-1520 ℃, and the time of the primary sintering is 2-5 h; the density of the primary blank is 94-98%;

in the third step, the pressure of hot isostatic pressing sintering is 50-200 MPa, and the time of hot isostatic pressing sintering is 1-3 h.

10. A fine-grained pink ZTA ceramic prepared by the method of any one of claims 1 to 9.