A method for preparing a calcium oxide ceramic core

Abstract

The application discloses a preparation method of a calcium oxide ceramic core, and comprises the following steps: coating calcium oxide powder once to obtain primary calcium oxide powder; preparing a calcium oxide photocuring ceramic slurry; preparing a calcium oxide ceramic base body blank through the photocuring ceramic slurry; pre-sintering the calcium oxide ceramic base body blank to obtain a calcium oxide ceramic base body; preparing an impregnation solution, and impregnating the calcium oxide ceramic base body through the impregnation solution; and drying and sintering the impregnated calcium oxide ceramic base body to obtain the calcium oxide ceramic core. The application solves the problem that the ceramic core reacts with molten titanium alloy during high-temperature casting, and simultaneously realizes that the ceramic core can be easily separated from the titanium alloy casting without damaging the casting.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of ceramic cores, in particular to a calcium oxide ceramic core preparation method. BACKGROUND

[0002] The complex inner cavity of a titanium alloy blade is mainly formed by using a prefabricated ceramic core, and various ceramic cores with complex structures can be prepared by using a 3D printing technology.

[0003] At present, the ceramic cores are mainly made of alumina and silicon oxide, but the ceramic cores made of alumina and silicon oxide have the problem that, in a high-temperature casting process, aluminum and silicon in the ceramic cores react with molten titanium alloy to form a pollution layer with high oxygen concentration, so that the contact surface of the titanium alloy casting becomes hard and brittle, and the elasticity and ductility of the titanium alloy casting are reduced, which greatly affects the performance of the titanium alloy casting.

[0004] Some ceramic cores are made of zirconium oxide and yttrium oxide materials with strong chemical stability, but the ceramic cores made of the zirconium oxide and yttrium oxide materials have the problem that the ceramic cores are difficult to remove, thereby leading to a low qualified rate of the castings.

[0005] Therefore, how to avoid the reaction between the ceramic core and the molten titanium alloy in the high-temperature casting process and how to avoid the problem that the ceramic core is easy to cause damage to the titanium alloy casting when the ceramic core is separated from the titanium alloy casting have become problems to be solved in the field. SUMMARY

[0006] The application aims to provide a calcium oxide ceramic core preparation method, which solves the problem that the ceramic core reacts with the molten titanium alloy in the high-temperature casting process and realizes that the ceramic core is easy to be separated from the titanium alloy casting without causing damage to the casting.

[0007] According to the application, a calcium oxide ceramic core preparation method is provided, in which calcium oxide powder is coated once to obtain primary calcium oxide powder; a calcium oxide photocuring ceramic slurry is prepared; a calcium oxide ceramic base body is prepared through the calcium oxide photocuring ceramic slurry; and the calcium oxide ceramic base body is pre-sintered to obtain a calcium oxide ceramic base.

[0008] An impregnation solution is prepared, and the calcium oxide ceramic base is impregnated through the impregnation solution; and the impregnated calcium oxide ceramic base is dried and sintered to obtain the calcium oxide ceramic core.

[0009] The application has the beneficial effect that the calcium oxide photocuring ceramic slurry is prepared to prepare the calcium oxide ceramic core, so that the calcium oxide ceramic core does not react with the molten titanium alloy in the high-temperature casting process.

[0010] The primary calcium oxide powder is obtained by coating the calcium oxide powder once, so that the reaction of the calcium oxide powder with water to become calcium hydroxide when the calcium oxide photocuring ceramic slurry is prepared is avoided.

[0011] The calcium oxide ceramic matrix is impregnated by the impregnation solution, which is further beneficial to avoid moisture of the calcium oxide ceramic matrix, and meanwhile improves the compactness of the surface of the calcium oxide ceramic core and the surface smoothness of the titanium alloy casting prepared by the calcium oxide ceramic core.

[0012] After the titanium alloy casting is poured by the calcium oxide ceramic core, the calcium oxide ceramic core is easily separated from the titanium alloy casting, and the calcium oxide ceramic core is easily broken and avoids damage to the titanium alloy casting.

[0013] Further, the specific process of the first coating of the calcium oxide powder is as follows:

[0014] The calcium oxide powder is mixed, ground and dried with the first coating solution at a mass ratio of (0.9-1.1):1 to obtain the primary calcium oxide powder.

[0015] The first coating solution comprises Y(NO3)3 and Zr(NO3)4 ethanol solution.

[0016] The beneficial effect of the above technical solution is that Y(NO3)3 and Zr(NO3)4 are coated on the surface of the calcium oxide powder by the first coating solution comprising Y(NO3)3 and Zr(NO3)4 ethanol solution, and the solvent is ethanol to avoid the problem of reaction between the calcium oxide and water during the coating process.

[0017] Further, the volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the first coating solution is (10-30):(10-30):(40-60).

[0018] The calcium oxide powder comprises 10 μm, 5 μm and 2 μm calcium oxide ceramic powders at a mass ratio of (52-58):(28-32):(12-18); and the particle size fluctuation range of the 10 μm, 5 μm and 2 μm calcium oxide ceramic powders is ±1%.

[0019] The beneficial effect of the above technical solution is that Y(NO3)3 and Zr(NO3)4 are coated on the surface of the calcium oxide powder by the first coating solution comprising Y(NO3)3 and Zr(NO3)4 ethanol solution, and the solvent is ethanol to avoid the problem of reaction between the calcium oxide and water during the coating process.

[0020] Further, the primary calcium oxide powder is used to prepare a calcium oxide light-cured ceramic slurry after the secondary coating.

[0021] The specific process of the secondary coating of the primary calcium oxide powder is as follows:

[0022] The primary calcium oxide powder is attached with paraffin wax or the surface of the primary calcium oxide powder is attached with an organic modifier solution; the organic modifier solution comprises an organic modifier and ethanol, and the organic modifier comprises one or more of trimethylchlorosilane, methyltrimethoxysilane, dimethyldimethoxysilane or trimethylmethoxysilane.

[0023] The mass ratio of the primary calcium oxide powder to the surface-attached paraffin wax or organic modifier is 1:(0.1-0.5).

[0024] Preferably, after the surface of the primary calcium oxide powder is attached with the organic modifier solution, a heating reaction is performed, and the heating temperature is 120-130℃; further preferably, the mass ratio of the organic modifier to ethanol is (1-5):(10-20).

[0025] The beneficial effects of the above technical solution are that, by performing secondary coating on the primary calcium oxide powder, the surface of the primary calcium oxide powder is attached with a hydrophobic substance, which is further conducive to avoiding the problem that the calcium oxide ceramic matrix is prone to moisture absorption during the preparation of the calcium oxide ceramic matrix and the storage process after preparation, resulting in deformation or strength reduction of the calcium oxide ceramic matrix; and the organic components and paraffin wax coated on the surface of the calcium oxide powder volatilize during the pre-sintering process of the calcium oxide ceramic matrix green body, and at the same time, the calcium oxide ceramic matrix further forms a through hole, which is conducive to the impregnation of the impregnation solution into the calcium oxide ceramic matrix.

[0026] Further, the specific process of preparing the calcium oxide photocuring ceramic slurry is as follows:

[0027] The primary calcium oxide powder, photocuring resin and dispersant are mixed in a mass ratio of (60-85):(30-40):(2-5) to obtain a calcium oxide photocuring ceramic slurry.

[0028] The photocuring resin comprises a first polymerized monomer, a second polymerized monomer, a diluent and a photoinitiator.

[0029] The dispersant comprises one or more of Span 20, Tween 80, BIK 103 and Triton 114; preferably, the mass ratio of the first polymerized monomer, the second polymerized monomer, the diluent and the photoinitiator is (60-70):(10-30):(5-15):(0.1-5).

[0030] The beneficial effects of the upper technical solution are that the ceramic particles, the photocuring resin and the dispersing agent are mixed in a mass ratio of (60-85):(30-40):(2-5), the content of the photocuring resin is low, which is beneficial to avoid the problem of high porosity of the ceramic core surface after sintering;

[0031] The ratio of the first polymerization monomer to the second polymerization monomer is (60-70):

[0032] (10-30), that is, the calcium oxide photocuring ceramic slurry has good fluidity, and the molding is fast during light-induced molding, and the calcium oxide ceramic matrix has sufficient strength; the problem of obvious reduction in the fluidity and dispersibility of the calcium oxide photocuring ceramic slurry when the content of the photocuring resin is low is avoided; at the same time, the first polymerization monomer and the second polymerization monomer are uniformly volatilized during the sintering process, which is beneficial to avoid the problems of difficult volatilization, many internal closed pores and cracks or damage of the calcium oxide ceramic core.

[0033] Further, the first polymerization monomer includes one or more of bisphenol A epoxy acrylate and ethoxyethoxyethyl acrylate; the second polymerization monomer includes polyurethane acrylate; and the diluent includes n-butanol or isopropyl alcohol.

[0034] The beneficial effects of the upper technical solution are that the first polymerization monomer and the second polymerization monomer contain double bonds and non-hydrophilic groups, so the first polymerization monomer and the second polymerization monomer are beneficial to uniform mixing with the calcium oxide powder after the first coating or the second coating;

[0035] The first polymerization monomer has a small molecular weight, a fast curing speed during light-induced polymerization, and a low molecular weight after polymerization, which is beneficial to volatilization during the subsequent sintering process.

[0036] The second polymerization monomer has a large molecular weight, which is beneficial to improving the strength of the calcium oxide ceramic matrix body.

[0037] Further, the specific process of pre-sintering the calcium oxide ceramic matrix body is as follows: heating from room temperature to 400-450℃ at a heating rate of 10-14.5℃ / min, then heating from 400-450℃ to 500-650℃ at a heating rate of 5-7℃ / min, and then heating from 500-650℃ to 1000-1150℃ at a heating rate of 3-4℃ / min.

[0038] The beneficial effect of the technical scheme in the previous step is that, by increasing from room temperature to 400-450 DEG C at a rate of 10-14.5 DEG C / min, it is beneficial to realize the fast speed of the small molecular weight dispersant volatilization, and although the molecular weight is small, the pore is slightly larger and is a through hole, which is beneficial to the subsequent large molecular weight polymer volatilization in the pore generated by the small molecular weight substance, and the rapid temperature rise is beneficial to the decomposition of the large molecular polymer without volatilization, avoiding the volatilization of the large molecular polymer on the basis of the pore generated by the volatilization of the small molecular substance, thereby avoiding the problems of closed pores, uneven pore distribution, or cracks or damage;

[0039] By increasing from 700-800 DEG C to 1000-1150 DEG C at a rate of 3-4 DEG C

[0040] / min, it is beneficial to the slow volatilization of the residual volatilization, and at the same time, it is beneficial to the further improvement of the preliminary reaction and bonding strength of the calcium oxide powder and the surface Y(NO3)3 and Zr(NO3)4, and the increase of the strength of the calcium oxide ceramic matrix and the generation of small active grains inside.

[0041] Further, the specific process of preparing the impregnation solution is: dissolving Zr(OH)4 and Y(OH)3 in anhydrous ethanol solution to prepare a sol solution;

[0042] The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the impregnation solution is (10-40):(10-40):(20-60).

[0043] The beneficial effect of the technical scheme in the previous step is that, by increasing from room temperature to 400-450 DEG C at a rate of 10-14.5 DEG C / min, it is beneficial to realize the fast speed of the small molecular weight dispersant volatilization, and although the molecular weight is small, the pore is slightly larger and is a through hole, which is beneficial to the subsequent large molecular weight polymer volatilization in the pore generated by the small molecular weight substance, and the rapid temperature rise is beneficial to the decomposition of the large molecular polymer without volatilization, avoiding the volatilization of the large molecular polymer on the basis of the pore generated by the volatilization of the small molecular substance, thereby avoiding the problems of closed pores, uneven pore distribution, or cracks or damage etc.

[0044] Further, the primary calcium oxide powder is coated twice and then granulated to obtain calcium oxide particles; the calcium oxide particles are used to prepare a calcium oxide photocuring ceramic slurry;

[0045] The specific preparation process of the calcium oxide particles is:

[0046] The primary calcium oxide powder after secondary coating, the solvent, the carbon powder and the binder are mixed in a mass ratio of 100:(10-15):(30-35):(30-60); the solvent is ethanol;

[0047] The ceramic particle body is obtained by spray drying;

[0048] The ceramic particle body is heated at a temperature of 300-500 DEG C to obtain the calcium oxide ceramic particle; preferably, the binder comprises polyethylene glycol 200, polyethylene glycol 400, polypropylene glycol 200, polypropylene glycol 400.

[0049] The beneficial effects of the technical solution of the above step are that, by granulation, the internal porosity of the calcium oxide particles is high, the inter-particle porosity of the calcium oxide particles is low, and the density is high, so that the calcium oxide ceramic core is easily broken and separated when the calcium oxide ceramic core is separated from the titanium alloy casting after casting the titanium alloy melt, the titanium alloy casting is not damaged, and the surface of the calcium oxide ceramic core is dense to achieve smooth surface of the titanium alloy casting.

[0050] Further, the sintering temperature of the sintering is 1450-1550 DEG C, and the sintering time is 2.8-3.5 hours.

[0051] The beneficial effects of the technical solution of the above step are that, by sintering at a temperature of 1450-1550 DEG C, the strength of the calcium oxide ceramic core is high, and the structure of the calcium oxide ceramic core is stable when contacted with the titanium alloy melt, and does not react with the titanium alloy melt. DETAILED DESCRIPTION

[0052] In order to better understand the technical solutions of the present application, the present application will be further described below in conjunction with specific embodiments.

[0053] Embodiment 1:

[0054] In one aspect of the present embodiment, a method for preparing a calcium oxide ceramic core is provided, which comprises coating calcium oxide powder once to obtain primary calcium oxide powder;

[0055] The calcium oxide powder and the first coating solution are mixed, ground and dried to obtain the primary calcium oxide powder; the first coating solution comprises Y(NO3)3 and Zr(NO3)4 ethanol solution.

[0056] The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the first coating solution is 20:20:50;

[0057] The calcium oxide powder comprises 10 μm, 5 μm and 2 μm calcium oxide ceramic powder in a mass ratio of 55:30:15; the particle size fluctuation range of the 10 μm, 5 μm and 2 μm calcium oxide ceramic powder is ±1%.

[0058] The calcium oxide photocuring ceramic slurry is prepared by mixing the primary calcium oxide powder, the photocuring resin and the dispersant according to the mass ratio of 73:35:3.5;

[0059] The photocuring resin comprises a first polymerized monomer, a second polymerized monomer, a diluent and a photoinitiator, and the mass ratio of the first polymerized monomer, the second polymerized monomer, the diluent and the photoinitiator is 65:20:10:2.5.

[0060] The dispersant comprises Span 20 and Tween 80.

[0061] The first polymerized monomer comprises bisphenol A epoxy acrylate and ethoxyethoxyethyl acrylate, the second polymerized monomer comprises polyurethane acrylate, and the diluent comprises n-butanol.

[0062] The calcium oxide ceramic matrix blank is prepared by the photocuring ceramic slurry, and the calcium oxide ceramic matrix is obtained by pre-sintering the calcium oxide ceramic matrix blank.

[0063] The specific process of pre-sintering the calcium oxide ceramic matrix blank is as follows: the temperature is raised from room temperature to 425℃ at a rate of 13℃ / min, then the temperature is raised from 425℃ to 570℃ at a rate of 6℃ / min, and then the temperature is raised from 570℃ to 1070℃ at a rate of 3.5℃ / min.

[0064] The impregnation solution is prepared, and the calcium oxide ceramic matrix is impregnated by the impregnation solution. The specific process of preparing the impregnation solution is as follows: Zr(OH)4 and Y(OH)3 are dissolved in anhydrous ethanol solution to prepare a sol solution; the volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the impregnation solution is 25:25:40.

[0065] The dried and sintered calcium oxide ceramic matrix is obtained by drying and sintering the impregnated calcium oxide ceramic matrix; the sintering temperature of the calcium oxide ceramic matrix is 1500℃, and the sintering time is 3.2 hours.

[0066] Example 2:

[0067] The same content as that of Example 2 is not described herein again; the different scheme of the present example from that of Example 2 is as follows:

[0068] The primary calcium oxide powder is used for preparing the calcium oxide photocuring ceramic slurry after secondary coating.

[0069] The specific process of secondary coating the primary calcium oxide powder is as follows: the organic modifier solution is attached to the surface of the calcium oxide powder; the organic modifier solution comprises an organic modifier and ethanol, and the organic modifier comprises trimethylchlorosilane and methyltrimethoxysilane.

[0070] The mass ratio of the primary calcium oxide powder and the surface-attached organic modifier is 1:0.3; after the primary calcium oxide powder is attached with the organic modifier solution, heating reaction is performed, the heating temperature is 125℃; the mass ratio of the organic modifier and ethanol is 3:15;

[0071] The primary calcium oxide powder is obtained by mixing, grinding and drying the calcium oxide powder and the first coating solution according to a mass ratio of 1.05:1;

[0072] The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the first coating solution is 25:20:55;

[0073] The calcium oxide powder comprises 10μm, 5μm and 2μm calcium oxide ceramic powders in a mass ratio of 56:31:17.

[0074] The primary calcium oxide powder after secondary coating, the photocuring resin and the dispersant are mixed according to a mass ratio of 82:32:4 to obtain a calcium oxide photocuring ceramic slurry;

[0075] The dispersant comprises BYK 103 and Triton 114;

[0076] The mass ratio of the first polymerized monomer, the second polymerized monomer, the diluent and the photoinitiator is 68:15:8:1;

[0077] The first polymerized monomer comprises ethoxyethoxyethyl acrylate and polyurethane acrylate; the second polymerized monomer comprises polyurethane acrylate; and the diluent comprises isopropyl alcohol.

[0078] The specific process of pre-sintering the calcium oxide ceramic matrix blank is as follows: heating from room temperature to 410℃ at a heating rate of 11℃ / min, then heating from 410℃ to 550℃ at a heating rate of 5.5℃ / min, and then heating from 550℃ to 1030℃ at a heating rate of 3.2℃ / min.

[0079] The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the impregnation solution is 15:35:50.

[0080] The sintering temperature of the calcium oxide ceramic matrix is 1470℃, and the sintering time is 3.2 hours.

[0081] Example 3:

[0082] The same content as that of Example 2 is not described herein again; the different scheme of this example from that of Example 2 is as follows:

[0083] The primary calcium oxide powder is granulated after secondary coating to obtain calcium oxide particles; and the calcium oxide particles are used to prepare a calcium oxide photocuring ceramic slurry.

[0084] The preparation process of the calcium oxide particles is as follows: the primary calcium oxide powder, the solvent, the carbon powder and the binder are mixed according to the mass ratio of 100:13:32:45 after secondary coating; then the ceramic particle body is obtained through spray drying; the solvent is ethanol; and the binder includes polyethylene glycol 200;

[0085] The ceramic particles are obtained through heating treatment of the ceramic particle body, and the heating treatment process of the ceramic particle body is that the heat treatment temperature is 400℃.

[0086] The mass ratio of the primary calcium oxide powder to the paraffin attached to the surface is 1:0.4.

[0087] The primary calcium oxide powder is obtained by mixing, grinding and drying the calcium oxide powder and the first coating solution according to the mass ratio of 0.95:1;

[0088] The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the first coating solution is 15:25:45.

[0089] The calcium oxide powder includes 10μm, 5μm and 2μm calcium oxide ceramic powders with a mass ratio of 53:29:14.

[0090] The specific process of the secondary coating of the primary calcium oxide powder is that the primary calcium oxide powder is attached with paraffin.

[0091] The calcium oxide photocuring ceramic slurry is obtained by mixing the ceramic particles, the photocuring resin and the dispersant according to the mass ratio of 65:38:3.

[0092] The dispersant includes Span 20 and BYK 103.

[0093] The mass ratio of the first polymerized monomer, the second polymerized monomer, the diluent and the photoinitiator is 62:28:12:3.

[0094] The first polymerized monomer includes bisphenol A epoxy acrylate; the second polymerized monomer includes polyurethane acrylate; and the diluent includes n-butanol.

[0095] The specific process of the pre-sintering of the calcium oxide ceramic matrix body is as follows: the temperature is raised from room temperature to 440℃ at a temperature raising rate of 13.5℃ / min, then the temperature is raised from 440℃ to 620℃ at a temperature raising rate of 6.5℃ / min, and then the temperature is raised from 620℃ to 1120℃ at a temperature raising rate of 3.8℃ / min.

[0096] The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the impregnation solution is 35:15:30.

[0097] The sintering temperature of the calcium oxide ceramic matrix is 1520 DEG C, and the sintering time is 2.9 hours. The above description is only the preferred embodiment of the present application and the explanation of the applied technical principles. It should be understood by those skilled in the art that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by the combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are similar to the functions disclosed in the present application (but not limited to)

Claims

1. A method for preparing a calcium oxide ceramic core, characterized in that, The method comprises the following steps: coating the calcium oxide powder once to obtain primary calcium oxide powder; preparing a calcium oxide photocuring ceramic slurry; preparing a calcium oxide ceramic matrix blank through the calcium oxide photocuring ceramic slurry; pre-sintering the calcium oxide ceramic matrix blank to obtain a calcium oxide ceramic matrix; preparing an impregnation solution and impregnating the calcium oxide ceramic matrix through the impregnation solution; drying and sintering the impregnated calcium oxide ceramic matrix to obtain the calcium oxide ceramic core; coating the primary calcium oxide powder twice to prepare a calcium oxide photocuring ceramic slurry; the specific process of coating the primary calcium oxide powder twice is as follows: attaching paraffin wax to the primary calcium oxide powder or attaching an organic modifier solution to the surface of the primary calcium oxide powder; the organic modifier solution comprises an organic modifier and ethanol; the organic modifier comprises one or more of trimethylchlorosilane, methyltrimethoxysilane, dimethyldimethoxysilane or trimethylmethoxysilane; the mass ratio of the primary calcium oxide powder to the surface-attached paraffin wax or organic modifier is 1:(0.1-0.5); granulating the primary calcium oxide powder after the second coating to obtain calcium oxide particles; the calcium oxide particles are used to prepare a calcium oxide photocuring ceramic slurry; the preparation process of the calcium oxide particles is as follows: mixing the primary calcium oxide powder after the second coating, a solvent, carbon powder and a binder according to a mass ratio of 100:(10-15):(30-35):(30-60); the solvent is ethanol; then obtaining ceramic particle blanks through spray drying; heating the ceramic particle blanks at a temperature of 300-500 DEG C to obtain calcium oxide particles.

2. The method of claim 1, wherein the specific process of coating the calcium oxide powder once is as follows: mixing, grinding and drying the calcium oxide powder and a first coating solution according to a mass ratio of (0.9-1.1):1 to obtain the primary calcium oxide powder; the first coating solution comprises an ethanol solution of Y(NO3)3 and Zr(NO3)4.

3. The method of claim 2, wherein the method further comprises the step of: the volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the first coating solution is (10-30):(10-30):(40-60). the calcium oxide powder comprises 10 μm, 5 μm and 2 μm calcium oxide ceramic powders according to a mass ratio of (52-58):(28-32):(12-18).

4. The method of claim 1, wherein the specific process of preparing the calcium oxide photocuring ceramic slurry is as follows: mixing the primary calcium oxide powder, photocuring resin and dispersant according to a mass ratio of (60-85):(30-40):(2-5) to obtain a calcium oxide photocuring ceramic slurry; the photocuring resin comprises a first polymerized monomer, a second polymerized monomer, a diluent and a photoinitiator; the dispersant comprises one or more of Span 20, Tween 80, BIK 103 and Triton 114.

5. The method of claim 4, wherein the first polymerized monomer comprises one or more of bisphenol A epoxy acrylate and ethoxyethoxyethyl acrylate; the second polymerized monomer comprises polyurethane acrylate; the diluent comprises n-butanol or isopropyl alcohol.

6. The method of claim 1, wherein The specific process of pre-sintering the calcium oxide ceramic matrix blank is as follows: heating from normal temperature to 400-450℃ at a heating rate of 10-14.5℃ / min, then heating from 400-450℃ to 500-650℃ at a heating rate of 5-7℃ / min, and then heating from 500-650℃ to 1000-1150℃ at a heating rate of 3-4℃ / min.

7. The method of claim 1, wherein The specific process of preparing the impregnation solution is as follows: Dissolving Zr(OH)4 and Y(OH)3 in anhydrous ethanol solution to prepare a sol solution; The volume ratio of Y(NO3)3, Zr(NO3)4 and ethanol in the impregnation solution is (10-40):(10-40):(20-60).

8. The method of claim 1, wherein The sintering temperature of the sintering is 1450-1550℃, and the sintering time is 2.8-3.5 hours.