A method for preparing zirconium aluminum composite oxide and a method for preparing composite ceramic substrate.

Abstract

This application relates to the field of alumina composite ceramic technology, specifically providing a method for preparing zirconium-aluminum composite oxide and a method for preparing a composite ceramic substrate. The method for preparing the zirconium-aluminum composite oxide involves adding boehmite to a zirconium salt aqueous solution with a concentration of 0.5~1.2 mol / L, gradually adding deionized water while stirring, continuing stirring for 5~15 hours after the addition is complete, adding a dispersant, and continuing stirring for 4~10 hours to obtain a first slurry; the first slurry is then passed through a 200-mesh sieve and dried until the moisture content is ≤5%, then calcined at 550~700℃ for 2~4 hours, cooled, pulverized, and sieved to obtain the final product. The composite ceramic substrate is obtained by ball milling, spray drying, pressing, isostatic pressing, microwave drying, and calcination of zirconium-aluminum composite oxide and yttrium oxide powder, exhibiting high strength and high fracture toughness.

Description

Technical Field

[0001] This application relates to the field of alumina composite ceramic technology, specifically to a method for preparing zirconium aluminum composite oxide and a method for preparing a composite ceramic substrate. Background Technology

[0002] Alumina ceramic substrates are currently the most technologically mature ceramic substrate material for manufacturing and processing. They possess advantages such as low dielectric loss, low temperature dependence of electrical properties, high mechanical strength, and good chemical stability, making them widely used in power electronics, electronic packaging, hybrid microelectronics, multi-chip modules, dental prosthetic materials, and communication equipment. However, alumina ceramic substrates suffer from poor thermal conductivity, typically requiring modification with other metal oxides or the fabrication of composite oxide-type ceramic substrates. These composite oxide-type substrates, on the other hand, exhibit higher flexural strength, fracture toughness, and thermal conductivity compared to alumina ceramic substrates.

[0003] Chinese invention patent CN114656245A discloses an alumina-based composite ceramic substrate and its preparation method, which is composed of the following raw materials: 80-100 parts of alumina, 15-25 parts of zirconium oxide, 7-12 parts of aluminum borate whiskers, 10-25 parts of sintering aid, 10-15 parts of plasticizer, 3-5 parts of dispersant, 10-20 parts of binder, and 75-105 parts of organic solvent. It improves the bending strength, fracture toughness and other properties of the alumina-based ceramic substrate, and can also improve the bonding strength with metals such as copper, aluminum and gold. Chinese invention patent CN113666724A discloses a high-strength zirconia-alumina composite ceramic substrate for semiconductor devices and its manufacturing method. The obtained zirconia-alumina composite ceramic substrate includes a matrix phase formed by micron-sized alumina particles, a second phase formed by submicron-sized zirconia particles dispersed in the matrix phase, and a sintering aid synthesized by pre-calcination. The three-point bending strength can reach more than 630 MPa, and the thermal conductivity of aluminum can reach 28 W / m·K.

[0004] The applicant believes that ongoing research is needed on alumina-based composite ceramics to further improve their performance. Summary of the Invention

[0005] The applicant believes that continuous research on alumina-based composite ceramics is necessary to further improve their performance. Based on this, this application provides a method for preparing zirconium-aluminum composite oxide and a method for preparing a composite ceramic substrate.

[0006] The technical solution adopted in this application is as follows:

[0007] A method for preparing a zirconium-aluminum composite oxide includes the following steps: adding boehmite to a zirconium salt aqueous solution with a concentration of 0.5–1.2 mol / L, gradually adding deionized water while stirring, continuing to stir for 5–15 hours after the addition is complete, adding a dispersant and continuing to stir for 4–10 hours to obtain a first slurry; the first slurry is passed through a 200-mesh sieve and dried until the moisture content is ≤5%, then heated to 550–700℃ and calcined for 2–4 hours, cooled, pulverized, and sieved to obtain the zirconium-aluminum composite oxide.

[0008] Preferably, the molar ratio of the zircon salt to the pseudoboehmite is 0.2 to 1.5:10.

[0009] Preferably, the weight ratio of the pseudoboehmite and the zircon salt to the weight of the deionized water is 1:2 to 3.

[0010] Preferably, the dispersant is selected from one or more of polymeric dispersants and nonionic surfactants.

[0011] Preferably, the weight ratio of the dispersant to the sum of the weights of the pseudoboehmite and the zircon salt is 3 to 8:100.

[0012] The method for preparing a composite ceramic substrate includes the following steps:

[0013] S1. The zirconium aluminum composite oxide and yttrium oxide powder prepared by the preparation method described in any of the above embodiments are added to water at a weight ratio of 90:10 to 95:5 and dispersed. The mixture is then ball-milled for 10 to 20 hours. Then, an additive is added and the mixture is ball-milled for another 5 to 10 hours to obtain a second slurry.

[0014] S2, Step S1: The second slurry is spray-dried to form powder, pressed into a blank, isostatically pressed, microwave-dried, and then placed in a kiln at 1550-1650℃ for 0.5-2 hours. After cooling, it is taken out to obtain the composite ceramic substrate.

[0015] Preferably, the weight ratio of the zirconium aluminum composite oxide and yttrium oxide powder to the weight of the water in step S1 is 1:0.8 to 1.2.

[0016] Preferably, the adjuvant in step S1 is selected from one or more combinations of glycerin, gum arabic, polyethylene glycol, carboxymethyl cellulose and hydroxypropyl cellulose.

[0017] Preferably, the auxiliary agent in step S1 is added in the form of an aqueous solution, the concentration of which is 5-20 wt%.

[0018] More preferably, the weight ratio of the aqueous solution to the water in step S1 is 3 to 10:100.

[0019] In summary, this application has the following beneficial effects:

[0020] 1. In this application, zirconium salt aqueous solution and pseudoboehmite are first mixed. Taking advantage of the characteristic that pseudoboehmite easily forms a sol in aqueous solution, the sol adsorbs zirconium salt and forms a good mixture with it. Then, zirconium-aluminum composite oxide can be obtained through simple drying and sieving steps. After testing, the composition of zirconium-aluminum composite oxide is very close to the feed ratio of the raw materials, and the overall composition of zirconium-aluminum composite oxide is very uniform.

[0021] 2. By ball milling the obtained zirconium-aluminum composite oxide with yttrium oxide, zirconium oxide and yttrium oxide modified alumina composite ceramics can be obtained. The preparation method is simple. Moreover, due to the use of boehmite, the obtained zirconium-aluminum composite oxide has higher activity, which is more conducive to calcination and the formation of more dense or more optimized composite ceramics. The obtained composite ceramic substrate has the characteristics of good fracture toughness and high mechanical strength.

[0022] 3. In the ball milling process of this application, after ball milling for a period of time, an additive is added, and it is found that a second slurry with more uniform particle size and composition distribution can be obtained, which helps to improve the performance of the composite ceramic substrate. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below.

[0024] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0025] On the one hand, this application proposes a method for preparing zirconium aluminum composite oxide, the steps of which include: adding boehmite to a zircon salt aqueous solution with a concentration of 0.5-1.2 mol / L, gradually adding deionized water while stirring at a stirring speed of 100-600 rpm, and continuing to stir for 5-15 hours after the addition is completed, during which time the boehmite gradually forms a sol and adsorbs and / or coats the zircon salt, and after adding a dispersant, continuing to stir for 4-10 hours to obtain the first slurry;

[0026] The first slurry is passed through a 200-mesh sieve and dried until the moisture content is ≤5%. It is then heated to 550–700℃ and calcined for 2–4 hours. After cooling, it is pulverized and sieved to obtain zirconium-aluminum composite oxide. Drying can be carried out in an oven at 100–120℃. When raising the temperature to the calcination temperature, the following heating procedure can be followed: the heating rate from room temperature to 350–400℃ can be 3–5℃ / min, and the heating rate to the calcination temperature can be 1–3℃ / min.

[0027] Boehmite is generally used in the preparation of catalysts, adsorbents, and supports. This application employs a method combining boehmite and zirconium salt to prepare zirconium-aluminum composite oxides. Boehmite, when dispersed in water, readily forms a sol and uniformly coats the zirconium salt, while simultaneously providing an aluminum source, thus facilitating the relatively simple preparation of homogeneous zirconium-aluminum composite oxides. Furthermore, the boehmite sol exhibits high activity, allowing for the formation of zirconium-aluminum composite oxides with zirconium salts at relatively low sintering temperatures.

[0028] In a preferred embodiment of this application, the molar ratio of zirconium salt to boehmite is 0.2–1.5:10. The zirconium-aluminum composite oxide of this application is primarily composed of alumina. Specifically, the molar ratio of zirconium salt to boehmite can be 0.2:10, 0.3:10, 0.4:10, 0.5:10, 0.6:10, 0.7:10, 0.8:10, 0.9:10, 1:10, 1.1:10, 1.2:10, 1.3:10, 1.4:10, 1.5:10, etc. In this application, there are no particular limitations on the zirconium salt; it can be zirconium oxychloride, zirconium oxysulfate, zirconium nitrate, zirconium acetate, zirconium sulfate, and zirconium chloride, etc., or a combination of two or more of these.

[0029] In a preferred embodiment of this application, the weight ratio of the sum of boehmite and zircon salt to the weight of deionized water is 1:2 to 3. By controlling the amount of deionized water added, the sol state of the boehmite can be adjusted, preventing the boehmite sol from being too thin or too thick, which would affect the effect. For example, the weight ratio of the sum of boehmite and zircon salt to the weight of deionized water can be 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, 1:3, etc.

[0030] In a preferred embodiment of this application, the dispersant is selected from one or more of polymeric dispersants and nonionic surfactants. Adding a dispersant can further disperse and stabilize the boehmite sol and zirconium salt complex, improving the uniformity and consistency of the zirconium-aluminum composite oxide composition. The polymeric dispersant refers to a dispersant with an average molecular weight of not less than 1000, and can be castor oil, polyacrylic acid (PAA) and its salts, polyethylene glycol (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), etc. The nonionic surfactant generally has a molecular weight not exceeding 500, with no particular limitations, and can be fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, Tween series, Span series, etc.

[0031] In a preferred embodiment of this application, the weight ratio of the dispersant to the sum of the weights of the pseudoboehmite and zircon salt is 3 to 8:100. Specifically, the weight ratio of the dispersant to the sum of the weights of the pseudoboehmite and zircon salt can be 3:100, 3.5:100, 4:100, 4.5:100, 5:100, 5.5:100, 6:100, 6.5:100, 7:100, 7.5:100, 8:100, etc.

[0032] On the other hand, this application proposes a method for preparing a composite ceramic substrate, the steps of which include:

[0033] S1. The zirconium aluminum composite oxide and yttrium oxide powder prepared by the preparation method described in any of the above embodiments are added to water at a weight ratio of 90:10 to 95:5 and dispersed. The mixture is then ball-milled for 10 to 20 hours. Then, an additive is added and the mixture is ball-milled for another 5 to 10 hours to obtain a second slurry.

[0034] S2. The second slurry in step S1 is spray-dried to form powder. After the powder is pressed into a blank, it is isostatically pressed, then microwave-dried, and then placed in a kiln to be calcined at 1550-1650℃ for 0.5-2 hours. After cooling, it is taken out to obtain the composite ceramic substrate of this application.

[0035] In step S1 of this application, zirconium oxide can be used as the grinding medium in the ball milling process of step S1. The weight of the grinding medium is 2 to 2.5 times the weight of the grinding slurry, the ball-to-material ratio can be 1:1 to 5:1, and the filling amount is not greater than 2 / 3 of the volume of the ball milling jar.

[0036] In a preferred embodiment of this application, the weight ratio of the sum of the zirconium aluminum composite oxide and yttrium oxide powder to water in step S1 is 1:0.8 to 1.2. A weight ratio of the sum of the zirconium aluminum composite oxide and yttrium oxide powder to water within the above range can obtain a dispersion of suitable concentration, which is beneficial for grinding. For example, the weight ratio of the sum of the zirconium aluminum composite oxide and yttrium oxide powder to water can be 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, etc.

[0037] In this application, the dispersion prepared from zirconium aluminum composite oxide and yttrium oxide powder is first ground. This process rapidly grinds large particles into smaller ones. Adding additives further reduces the particle size, resulting in higher particle size uniformity and more uniform component distribution. The inventors have found that this method, compared to adding the grinding aid earlier in the grinding system, produces a second slurry with better particle size and component uniformity, leading to better fracture toughness and mechanical strength in the resulting composite ceramic. In a preferred embodiment of this application, the additives in step S1 are not particularly limited and can be selected from one or more combinations of glycerol, gum arabic, polyethylene glycol (PEG), carboxymethyl cellulose (CMC), and hydroxypropyl cellulose.

[0038] In a preferred embodiment of this application, the additive is added in step S1 in the form of an aqueous solution, with a concentration of 5–20 wt%. Adding the additive in aqueous solution allows for faster and more uniform dispersion in the grinding system, improving the grinding effect. For example, the concentration of the additive aqueous solution can be 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, etc.

[0039] In a more preferred embodiment of this application, the weight ratio of the aqueous solution of the additive to the water in step S1 is 3 to 10:100. For example, the weight ratio can be 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, etc.

[0040] In this application, isostatic pressing can be cold isostatic pressing, and the pressure can be 200-500 MPa; the microwave frequency for microwave drying can be 300-300,000 MHz / s, and the time is 10 min-2 h. The heating rate during furnace calcination in step S2 can be 3-10 °C / min, and the temperature can be directly increased from room temperature to the calcination temperature.

[0041] The technical solution of this application will be described in detail below with reference to embodiments and comparative examples.

[0042] Examples 1-5: Preparation of Zirconium-Aluminum Composite Oxides

[0043] Example 1

[0044] The concentration of the zirconium oxychloride aqueous solution was 0.9 mol / L; the molar ratio of zirconium oxychloride to boehmite was 0.8:10; the weight ratio of the sum of the weights of boehmite and zirconium oxychloride to the weight of deionized water was 1:2.5; the dispersant was PEG-4000, and the weight ratio of PEG-4000 to the sum of the weights of boehmite and zirconium oxychloride was 5:100.

[0045] Boehmite was added to a zirconium oxychloride aqueous solution, and deionized water was gradually added while stirring at 300 rpm. The addition was completed in 0.5 hours, and stirring was continued for 10 hours. As stirring continued, the boehmite gradually formed a sol. PEG-4000 was added and stirring was continued for 7 hours to obtain a slurry.

[0046] After passing through a 200-mesh sieve, the slurry is dried in a 110℃ forced-air drying oven until the moisture content is ≤5%, obtaining powder. The powder is heated to 360℃ at a heating rate of 3℃ / min, then heated to 630℃ at a heating rate of 2℃ / min and calcined at a constant temperature for 3 hours. After natural cooling, it is pulverized and passed through a 60-mesh sieve to obtain zirconium aluminum composite oxide.

[0047] Example 2

[0048] The difference between Example 2 and Example 1 is that in Example 1, the molar ratio of zirconium oxychloride and boehmite was adjusted from 0.8:10 to 1.4:10. The remaining steps remained unchanged.

[0049] Example 3

[0050] The difference between Example 3 and Example 1 is that in Example 1, the molar ratio of zirconium oxychloride and boehmite was adjusted from 0.8:10 to 0.3:10. The remaining steps remained unchanged.

[0051] Example 4

[0052] The concentration of the zirconium oxysulfate aqueous solution is 0.6 mol / L; the molar ratio of zirconium oxysulfate to boehmite is 1:10; the weight ratio of the sum of the weights of boehmite and zirconium oxysulfate to the weight of deionized water is 1:2.8; the zirconium oxysulfate is castor oil, and the weight ratio of the castor oil to the sum of the weights of boehmite and zirconium oxysulfate is 4:100.

[0053] Boehmite was added to an aqueous solution of zirconium oxysulfate, and deionized water was gradually added while stirring at a speed of 200 rpm. The addition was completed in 20 minutes, and stirring was continued for 12 hours. As stirring was carried out, the boehmite gradually formed a sol. Castor oil was added and stirring was continued for 6 hours to obtain a slurry.

[0054] After passing through a 200-mesh sieve, the slurry is dried in a 105℃ forced-air drying oven until the moisture content is ≤5%, obtaining powder. The powder is heated to 360℃ at a heating rate of 5℃ / min, then heated to 670℃ at a heating rate of 3℃ / min and calcined at a constant temperature for 2.5 hours. After natural cooling, it is pulverized and passed through a 60-mesh sieve to obtain zirconium aluminum composite oxide.

[0055] Example 5

[0056] The difference between Example 5 and Example 4 is that in Example 4, the concentration of the zirconium oxysulfate aqueous solution was adjusted from 0.6 mol / L to 1.2 mol / L. The remaining steps remained unchanged.

[0057] Comparative Example 1

[0058] Zirconia and alumina were mixed and dispersed at a molar ratio of 0.4:10 and with 1.2 times their weight of deionized water. The mixture was then transferred to a planetary high-energy ball mill for ball milling. The milling media were quenched steel balls, with a ball-to-material ratio of 5:1 and a filling volume of 60% of the mill jar. The milling process lasted 30 hours to obtain a slurry. The slurry was dried in a 110℃ forced-air drying oven until the moisture content did not exceed 10%. It was then placed in a furnace and calcined at 6℃ / min to 630℃ for 3 hours. After cooling to room temperature, the slurry was pulverized to obtain zirconium-aluminum composite oxide.

[0059] Comparative Example 2

[0060] Zirconium nitrate and aluminum nitrate were added to water at a molar ratio of 0.8:10 to prepare a 0.9 mol / L aqueous solution. This solution was then added dropwise to twice the volume of a 25 wt% ammonia solution, and stirred for 10 hours to obtain a precipitate. The precipitate was aged at 70°C for 10 hours, filtered, and the solid was washed with deionized water until neutral. It was then dried in a 110°C oven until the moisture content did not exceed 10%. Finally, it was placed in a furnace and calcined at 900°C for 3 hours at a heating rate of 6°C / min. After cooling to room temperature, the precipitate was pulverized to obtain a zirconium-aluminum composite oxide.

[0061] Performance Tests and Results

[0062] Take 100g of zirconium-aluminum composite oxide powder obtained in Examples 1-5 and Comparative Examples 1-2, spread it out, and randomly select 6 positions (6 positions of each powder sample are close to each other) to test the molar ratio of zirconium and aluminum in the powder and compare the uniformity of the powder composition.

[0063] The results are shown in Table 1 below.

[0064] Table 1. Molar ratio of zirconium to aluminum, with aluminum as 10.

[0065]

[0066]

[0067] As shown in Table 1, the zirconium-aluminum composite oxide prepared by the method of this application has better component uniformity than existing powder grinding and precipitation methods.

[0068] Examples 6-12: Preparation of Composite Ceramic Substrates

[0069] Example 6

[0070] In Example 1, zirconium aluminum composite oxide and yttrium oxide powder were added to a mixture of zirconium aluminum composite oxide and yttrium oxide powder at a weight ratio of 90:10 and water at a weight ratio of 1:1 for dispersion. The mixture was then added to a ball mill jar with zirconium oxide as the milling medium, a ball-to-powder ratio of 2:1, and a filling amount of 60% of the ball mill jar volume. After ball milling for 15 hours, an additive—a 10wt% CMC aqueous solution—was added. The weight ratio of CMC aqueous solution to water was 5:100. Ball milling continued for 7 hours to obtain a slurry.

[0071] The slurry was spray-dried into powder using a spray granulation tower. The powder was pressed into blanks of 10cm×10cm×2mm and then cold isostatically pressed under a pressure of 220MPa. After microwave drying, the blanks were placed in a kiln and heated to 1610℃ at a heating rate of 7℃ / min. They were then calcined at a constant temperature for 1 hour, cooled naturally, and removed to obtain a composite ceramic substrate.

[0072] Example 7

[0073] The difference between Example 7 and Example 6 is that in Example 6, the zirconium aluminum composite oxide of Example 1 is replaced with an equal weight of the zirconium aluminum composite oxide of Example 2. The remaining steps remain unchanged.

[0074] Example 8

[0075] The difference between Example 8 and Example 6 is that in Example 6, the zirconium aluminum composite oxide of Example 1 is replaced with an equal weight of the zirconium aluminum composite oxide of Example 3. The remaining steps remain unchanged.

[0076] Comparative Example 3

[0077] The difference between Comparative Example 3 and Example 6 is that in Example 6, the zirconium aluminum composite oxide of Example 1 was replaced with an equal weight of the zirconium aluminum composite oxide of Comparative Example 1. The remaining steps remained unchanged.

[0078] Comparative Example 4

[0079] The difference between Comparative Example 4 and Example 6 is that in Example 6, the zirconium aluminum composite oxide of Example 1 was replaced with an equal weight of the zirconium aluminum composite oxide of Comparative Example 2. The remaining steps remained unchanged.

[0080] Comparative Example 5

[0081] In Example 1, zirconium aluminum composite oxide and yttrium oxide powder were added to water at a weight ratio of 90:10 and dispersed. Then, 5% of water by weight of a 10wt% CMC aqueous solution was added, and the mixture was transferred to a ball mill jar. The ball milling media was zirconium oxide, the ball-to-powder ratio was 2:1, and the filling amount was 60% of the ball mill jar volume. The mixture was ball milled for 22 hours to obtain a slurry.

[0082] The slurry was spray-dried, pressed, cold isostatically pressed, dried, and sintered according to the method in Example 1 to obtain a composite ceramic substrate.

[0083] Example 9

[0084] In Example 1, zirconium aluminum composite oxide and yttrium oxide powder were added to water at a weight ratio of 95:5 and 1.2 times their weight for dispersion. The mixture was then added to a ball mill jar with zirconium oxide as the milling medium, a ball-to-material ratio of 2:1, and a filling amount of 60% of the ball mill jar volume. After ball milling for 18 hours, an auxiliary agent—a 15wt% glycerol aqueous solution—was added. The weight ratio of CMC aqueous solution to water was 3:100. Ball milling continued for 9 hours to obtain a slurry.

[0085] The slurry was spray-dried into powder using a spray granulation tower. The powder was pressed into blanks of 10cm×10cm×2mm and then cold isostatically pressed under a pressure of 350MPa. After microwave drying, the blanks were placed in a kiln and heated to 1630℃ at a heating rate of 5℃ / min. They were then calcined at a constant temperature for 1 hour, allowed to cool naturally, and removed to obtain a composite ceramic substrate.

[0086] Example 10

[0087] The difference between Example 10 and Example 9 is that the zirconium aluminum composite oxide in Example 1 is replaced with an equal weight of the zirconium aluminum composite oxide in Example 2. The remaining steps remain unchanged.

[0088] Example 11

[0089] The difference between Example 11 and Example 9 is that the zirconium aluminum composite oxide in Example 1 is replaced with an equal weight of the zirconium aluminum composite oxide in Example 3. The remaining steps remain unchanged.

[0090] Example 12

[0091] The difference between Example 12 and Example 9 is that the zirconium aluminum composite oxide in Example 1 is replaced with an equal weight of the zirconium aluminum composite oxide in Example 4. The remaining steps remain unchanged.

[0092] Comparative Example 6

[0093] The difference between Comparative Example 6 and Example 9 is that in Example 9, the weight ratio of zirconium aluminum composite oxide and yttrium oxide powder was adjusted from 95:5 to 97:3. The remaining steps remained unchanged.

[0094] Comparative Example 7

[0095] The difference between Comparative Example 7 and Example 9 is that in Example 9, the weight ratio of zirconium aluminum composite oxide and yttrium oxide powder was adjusted from 95:5 to 85:15. The remaining steps remained unchanged.

[0096] The performance results of the composite ceramics of Examples 6-12 and Comparative Examples 3-7 are shown in Table 2 below.

[0097] Table 2

[0098]

[0099]

[0100] As can be seen from the data results in Table 2 above, the composite ceramic substrate obtained by using the zirconium aluminum composite oxide of this application in combination with the preparation method of this application has high fracture toughness and bending strength.

[0101] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a composite ceramic substrate, characterized in that the steps include... include: S1. Add zirconium aluminum composite oxide and yttrium oxide powder to water at a weight ratio of 90:10 to 95:5, disperse them, and then ball mill for 10 to 20 hours. Add additives and continue ball milling for 5 to 10 hours to obtain the second slurry. S2, Step S1: The second slurry is spray-dried to form powder, pressed into a blank, isostatically pressed, microwave-dried, and then placed in a kiln at 1550~1650℃ for 0.5~2 hours. After cooling, it is taken out to obtain the composite ceramic substrate. The preparation method of the zirconium-aluminum composite oxide is as follows: Boehmite is added to a zirconium salt aqueous solution with a concentration of 0.5~1.2 mol / L, and deionized water is gradually added while stirring. After the addition is complete, stirring is continued for 5~15 hours. After adding a dispersant, stirring is continued for 4~10 hours to obtain a first slurry. The first slurry is passed through a 200-mesh sieve and dried until the moisture content is ≤5%. Then, it is heated to 550~700℃ and calcined for 2~4 hours. After cooling, it is pulverized and sieved to obtain the zirconium-aluminum composite oxide. The molar ratio of the zirconium salt to the pseudoboehmite is 0.2–1.5:10; The weight ratio of the pseudoboehmite and the zircon salt to the weight of the deionized water is 1:2~3; The dispersant is selected from one or more of polymeric dispersants and nonionic surfactants; The weight ratio of the dispersant to the sum of the weights of the pseudoboehmite and the zircon salt is 3 to 8:

100.

2. The method for preparing the composite ceramic substrate according to claim 1, characterized in that, In step S1, the weight ratio of the zirconium aluminum composite oxide and yttrium oxide powder to the weight of the water is 1:0.8~1.

2.

3. The method for preparing the composite ceramic substrate according to claim 2, characterized in that, The auxiliary agent mentioned in step S1 is selected from one or more combinations of glycerin, gum arabic, polyethylene glycol, carboxymethyl cellulose and hydroxypropyl cellulose.

4. The method for preparing the composite ceramic substrate according to claim 3, characterized in that, The auxiliary agent mentioned in step S1 is added in the form of an aqueous solution with a concentration of 5-20 wt%.

5. The method for preparing the composite ceramic substrate according to claim 4, characterized in that, The weight ratio of the aqueous solution to the water in step S1 is 3~10:100.

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