Aluminum-magnesium spinel ceramic with high resistance as well as preparation method and application of aluminum-magnesium spinel ceramic

Abstract

The invention discloses high-resistance aluminum-magnesium spinel ceramic as well as a preparation method and application thereof, and relates to the technical field of preparation of ceramic materials. The ceramic comprises the following raw materials in parts by weight: 28-32 parts of silicon dioxide, 15-17 parts of magnesium oxide, 38-42 parts of aluminum oxide, 1-3 parts of lanthanum oxide, 2-5 parts of zirconium oxide, 1.5-2.5 parts of calcium oxide, 0.8-1.2 parts of tantalum oxide, 2-4 parts of titanium oxide and 1-3 parts of zinc oxide. The method provided by the invention has the advantages of low energy consumption, high production efficiency, high insulation resistance and the like, and solves the problems of low yield, complex equipment structure, high production cost and the like of the existing preparation method.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic material preparation, and in particular to an aluminum-magnesium spinel ceramic with high resistance and a preparation method and application thereof. Background Art

[0002] Aluminum-magnesium spinel ceramics are an advanced material with ultra-high temperature heat resistance. The main components are spinel phases of aluminum and magnesium oxides. They have excellent high temperature resistance, oxidation resistance, thermal shock resistance and other properties. They can maintain good structural stability in extreme high temperature environments. Therefore, they are widely used in aerospace, metallurgy, petrochemical, nuclear energy and other fields. Especially in the aerospace industry, the application of aluminum-magnesium spinel ceramics is particularly important for bonding, sealing, repair and protection in high temperature environments. They can meet the working requirements of more than 1700℃ and significantly improve the safety and stability of equipment. In the context of my country's vigorous promotion of the energy revolution, high insulation materials are crucial to the reliability of high-voltage transmission systems. Aluminum-magnesium spinel ceramics are suitable for ultra-high voltage direct current transmission lines and ultra-high voltage equipment, and have excellent corrosion resistance and thermal aging resistance. Aluminum-magnesium spinel ceramics with good electrical insulation have important applications in electrical equipment, electronic components and electrical insulation components in high temperature environments. For example, in chip substrate packaging, aluminum-magnesium spinel high-temperature ceramics effectively block leakage current while ensuring thermal management.

[0003] The existing preparation methods of the traditional solid-phase reaction method mostly focus on the mechanical strength and thermal stability of the material, and the control of the resistance performance is relatively weak, resulting in the resistance value of the finished product cannot be stably controlled within the required range, affecting the reliability and application effect of the product. In the existing preparation process, the ratio of aluminum and magnesium sources and the control of reaction conditions are relatively complicated, which can easily cause instability in product performance. In the existing preparation methods, it is often difficult to obtain aluminum-magnesium spinel ceramics with good dispersibility and high adhesion, which affects its actual application effect.

[0004] Aluminum-magnesium spinel ceramics have broad application prospects in the defense industry, electronic packaging and other fields. However, their preparation methods also have some disadvantages: 1. The high resistivity of aluminum-magnesium spinel is closely related to the purity, crystal structure and microscopic pore distribution of the material. At present, there is a lack of effective solutions for the controllability of the electrical insulation properties of the finished product, which often leads to large fluctuations in the resistance performance of the product in different batches or under different high-temperature environments; 2. The effective migration of aluminum and magnesium ions in aluminum-magnesium spinel ceramics is the key to achieving high performance. However, in the existing preparation methods, the efficiency and reaction rate of material migration are often low, resulting in unsatisfactory performance. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide an aluminum-magnesium spinel ceramic with high resistance and its preparation method and application, so as to solve the problems of low yield, complex equipment structure and high production cost of the existing preparation method.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: Provide an aluminum-magnesium spinel ceramic with high resistance, comprising the following raw materials in parts by weight: 28-32 parts of silicon dioxide, 15-17 parts of magnesium oxide, 38-42 parts of aluminum oxide, 1-3 parts of lanthanum oxide, 2-5 parts of zirconium oxide, 1.5-2.5 parts of calcium oxide, 0.8-1.2 parts of tantalum oxide, 2-4 parts of titanium oxide and 1-3 parts of zinc oxide.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows:

[0008] Further, the following raw materials are included in parts by weight: 30 parts of silicon dioxide, 16 parts of magnesium oxide, 40 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 1 part of tantalum oxide, 3 parts of titanium oxide and 2 parts of zinc oxide.

[0009] The beneficial effects of adopting the above further technical solution are:

[0010] The above raw material ratio can produce a better product, mainly due to the careful design of the proportions and synergy of the components. Specifically, the high content of alumina provides the main mechanical strength and high temperature resistance, and together with magnesium oxide forms MgAl 2 O 4 The spinel structure enhances the overall thermal stability and thermal shock resistance; a small amount of zinc oxide plays a liquid phase auxiliary role in the sintering process, which helps to reduce the sintering temperature and promote densification; at the same time, lanthanum oxide helps to refine the grains and improve the microstructure, further improving the mechanical properties of the material; zirconium oxide, as a toughening agent, can effectively inhibit crack propagation and enhance impact resistance; and calcium oxide plays a role in fluxing and stabilizing the microstructure. The various components complement each other, not only ensuring the stability and high temperature performance of the main matrix, but also optimizing the sintering process, reducing the defect rate, and improving the density and micro-uniformity through the regulation of trace additives, so that the final product has excellent performance in mechanical properties, thermal stability, electrical resistance and other aspects.

[0011] Furthermore, the purity of silicon dioxide is ≥99.9%, and the BET particle size is 10-20nm; the purity of magnesium oxide is ≥99.9%, and the particle size is 100-300nm; the purity of aluminum oxide is ≥99.9%, and the particle size is 50-200nm; the purity of lanthanum oxide is ≥99.5%; the purity of zirconium oxide is ≥99.5%, and the particle size is 200-500nm; the purity of calcium oxide is ≥99.5%; the purity of tantalum oxide is ≥99%; and the purity of zinc oxide containing titanium oxide is ≥99.5%.

[0012] The present invention also provides a method for preparing the above-mentioned aluminum-magnesium spinel ceramic with high resistance, comprising the following steps:

[0013] (1) adding the raw materials to the dispersant, ball milling and mixing to obtain a slurry, drying, sieving, and obtaining a powder;

[0014] (2) heating the powder obtained in step (1) to 900-1100° C., placing it in a chlorine and argon atmosphere, keeping the temperature for 1.5-2.5 h, then placing it in an argon atmosphere, cooling it to room temperature, grinding it, and sieving it to obtain a precursor powder;

[0015] (3) placing the precursor powder obtained in step (2) into a mold and statically pressing to obtain a green embryo;

[0016] (4) The green body obtained in step (3) is heated to 1250-1350° C. in an air atmosphere, kept at this temperature for 5-7 hours, then heated to 1380-1420° C. in an argon atmosphere at 130-170 MPa, kept at this temperature for 1.5-2.5 hours, and then cooled to room temperature to obtain an aluminum-magnesium spinel ceramic with high resistance.

[0017] Furthermore, in step (1), the dispersant is anhydrous ethanol or Reax-85A.

[0018] Furthermore, in step (1), the mixture is ball-milled at 200-300 rpm for 12-24 hours.

[0019] Furthermore, in step (1), drying is performed in a water-free environment.

[0020] Furthermore, in step (1), sieving is performed using a 100-200 mesh sieve.

[0021] Furthermore, in step (2), the powder obtained in step (1) is heated to 1000°C.

[0022] Furthermore, in step (2), the flow ratio of chlorine gas to argon gas is 1:1-2.

[0023] Furthermore, in step (3), static pressure is applied at 150-200 MPa for 2-3 min.

[0024] Furthermore, in step (4), the temperature is raised to 1300° C. and kept at this temperature for 6 h, then raised to 1400° C. under argon and 150 MPa conditions, and then cooled to room temperature.

[0025] The beneficial effects of adopting the above further technical solution are: static pressure sintering significantly improves the density of the material by applying static pressure, accelerates the diffusion and rearrangement between solid particles, thereby quickly eliminating pores and reducing the porosity in the final product, thereby enhancing the overall mechanical strength and stability. At the same time, static pressure helps the mixed powder to be evenly distributed throughout the sample, avoiding local density unevenness, which is particularly critical for multiphase ceramic systems; in addition, pressure-assisted sintering can achieve full densification at a lower temperature, effectively inhibit the excessive growth of grains, and maintain a small and uniform grain size, thereby improving the mechanical properties and thermal shock resistance of the material. Furthermore, since the external pressure makes the contact between particles closer, the sintering reaction is easier to carry out, thereby reducing the overall sintering temperature, reducing the adverse phase change or grain growth problems that may occur at high temperatures, and shortening the required insulation time, improving production efficiency and reducing energy consumption.

[0026] Furthermore, in step (4), the heating rate is 3-7°C / min.

[0027] The present invention also provides application of the aluminum-magnesium spinel ceramic with high resistance in national defense industry or electronic packaging.

[0028] The present invention has the following beneficial effects:

[0029] 1. The traditional synthesis method has the problem of increasing the number of micropores and reducing the density by adding magnesium content to increase the insulation performance. The components such as tantalum oxide and lanthanum oxide added in the present invention accelerate the densification process and improve the uniformity of the microstructure. In addition, the added silicon dioxide component effectively improves the overall insulation performance of the material at high temperature.

[0030] 2. The present invention proposes a method of introducing chlorine gas during the reaction stage, thereby changing the original reaction process. The present invention further reduces the activation energy required for the reaction through the chlorination reaction of magnesium oxide, greatly reduces the temperature required for the generation of the aluminum-magnesium spinel state during heat treatment, and significantly increases the yield of the aluminum-magnesium spinel.

[0031] 3. The method of the present invention has the advantages of low energy consumption, high production efficiency, high insulation resistance, etc., and solves the problems of low yield rate, complex equipment structure, high production cost, etc. of the existing preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a process flow chart of the present invention;

[0033] Figure 2 is the insulation resistance of the aluminum-magnesium spinel ceramics prepared in Example 1 and Comparative Examples 1-8;

[0034] Figure 3 The porosity of the aluminum-magnesium spinel ceramics prepared in Example 1 and Comparative Examples 1-8. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0036] Embodiment 1:

[0037] A high-resistance aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 30 parts of silicon dioxide, 16 parts of magnesium oxide, 40 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 1 part of tantalum oxide, 3 parts of titanium oxide and 2 parts of zinc oxide.

[0038] Among them, the purity of silica is 99.9% and the BET particle size is 15nm;

[0039] The purity of magnesium oxide is 99.9%, and the particle size is 200nm;

[0040] Alumina purity 99.9%, particle size 100nm;

[0041] Lanthanum oxide purity 99.5%;

[0042] Zirconia purity 99.5%, particle size 300nm;

[0043] Calcium oxide purity 99.5%;

[0044] Tantalum oxide purity 99%;

[0045] Titanium oxide purity 99.5%;

[0046] Zinc oxide purity 99.5%.

[0047] A method for preparing aluminum-magnesium spinel ceramics with high resistance comprises the following steps: (see Figure 1 )

[0048] (1) adding the raw materials to a dispersant (anhydrous ethanol), ball milling and mixing at 300 rpm for 24 h to obtain a slurry, drying in an anhydrous environment to avoid moisture absorption, and sieving with a 100-mesh sieve to obtain a powder;

[0049] (2) placing the powder obtained in step (2) into a crucible, heating it to 1000° C., introducing chlorine gas and argon gas (flow ratio of 1:1) in sequence, keeping the temperature for 2 h, introducing argon gas, cooling to room temperature, grinding, and sieving to obtain a precursor powder;

[0050] (3) The precursor powder obtained in step (2) is placed into a mold and statically pressed at 200 MPa for 3 min to obtain a green embryo;

[0051] (4) The green body obtained in step (3) is heated to 1300° C. in an air atmosphere, kept at this temperature for 6 h, then heated to 1400° C. in an argon atmosphere at 150 MPa, with a heating rate of 5° C. / min, kept at this temperature for 2 h, and then cooled to room temperature to obtain an aluminum-magnesium spinel ceramic with high resistance.

[0052] Embodiment 2:

[0053] A high-resistance aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 28 parts of silicon dioxide, 15 parts of magnesium oxide, 38 parts of aluminum oxide, 1 part of lanthanum oxide, 2 parts of zirconium oxide, 1.5 parts of calcium oxide, 0.8 parts of tantalum oxide, 2 parts of titanium oxide and 1 part of zinc oxide.

[0054] Among them, the purity of silica is 99.9% and the BET particle size is 10nm;

[0055] The purity of magnesium oxide is 99.9%, and the particle size is 100nm;

[0056] Alumina purity 99.9%, particle size 50nm;

[0057] Lanthanum oxide purity 99.5%;

[0058] Zirconia purity 99.5%, particle size 200nm;

[0059] Calcium oxide purity 99.5%;

[0060] Tantalum oxide purity 99%;

[0061] Titanium oxide purity 99.5%;

[0062] Zinc oxide purity 99.5%.

[0063] A method for preparing aluminum-magnesium spinel ceramics with high resistance comprises the following steps:

[0064] (1) adding the raw materials to a dispersant (Reax-85A), ball milling and mixing at 200 rpm for 12 h to obtain a slurry, drying in an anhydrous environment to avoid moisture absorption, and sieving with a 150-mesh sieve to obtain a powder;

[0065] (2) placing the powder obtained in step (2) into a crucible, heating it to 900° C., introducing chlorine gas and argon gas in sequence (at a flow ratio of 1:1.5), keeping the temperature for 2.5 h, introducing argon gas, cooling to room temperature, grinding, and sieving to obtain a precursor powder;

[0066] (3) The precursor powder obtained in step (2) is placed into a mold and statically pressed at 150 MPa for 2 min to obtain a green embryo;

[0067] (4) The green body obtained in step (3) was heated to 1250°C in an air atmosphere and kept at this temperature for 7 hours, and then heated to 1380°C in an argon atmosphere and 130 MPa at a heating rate of 3°C / min, kept at this temperature for 2.5 hours, and cooled to room temperature to obtain an aluminum-magnesium spinel ceramic with high resistance.

[0068] Embodiment 3:

[0069] A high-resistance aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 32 parts of silicon dioxide, 17 parts of magnesium oxide, 42 parts of aluminum oxide, 3 parts of lanthanum oxide, 5 parts of zirconium oxide, 2.5 parts of calcium oxide, 1.2 parts of tantalum oxide, 4 parts of titanium oxide and 3 parts of zinc oxide.

[0070] Among them, the purity of silica is 99.9% and the BET particle size is 20nm;

[0071] The purity of magnesium oxide is 99.9%, and the particle size is 300nm;

[0072] Alumina purity 99.9%, particle size 200nm;

[0073] Lanthanum oxide purity 99.5%;

[0074] Zirconia purity 99.5%, particle size 500nm;

[0075] Calcium oxide purity 99.5%;

[0076] Tantalum oxide purity 99%;

[0077] Titanium oxide purity 99.5%;

[0078] Zinc oxide purity 99.5%.

[0079] A method for preparing aluminum-magnesium spinel ceramics with high resistance comprises the following steps:

[0080] (1) adding the raw materials to a dispersant (anhydrous ethanol), ball milling and mixing at 250 rpm for 18 h to obtain a slurry, drying in an anhydrous environment to avoid moisture absorption, and sieving with a 200-mesh sieve to obtain a powder;

[0081] (2) placing the powder obtained in step (2) into a crucible, heating it to 1100° C., introducing chlorine gas and argon gas (flow ratio of 1:2) in sequence, keeping the temperature for 1.5 h, introducing argon gas, cooling to room temperature, grinding, and sieving to obtain a precursor powder;

[0082] (3) The precursor powder obtained in step (2) is placed into a mold and statically pressed at 180 MPa for 2.5 min to obtain a green embryo;

[0083] (4) The green body obtained in step (3) was heated to 1350° C. in an air atmosphere and kept at this temperature for 5 h. Then, the temperature was raised to 1420° C. in an argon atmosphere and 170 MPa at a heating rate of 7° C. / min. The temperature was kept at this temperature for 1.5 h and then cooled to room temperature to obtain an aluminum-magnesium spinel ceramic with high resistance.

[0084] Comparative Example 1:

[0085] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 20 parts of silicon dioxide, 16 parts of magnesium oxide, 40 parts of aluminum oxide, 2 parts of lanthanum oxide, 4 parts of zirconium oxide, 3 parts of calcium oxide, 0.5 parts of tantalum oxide, 6 parts of titanium oxide, and 4 parts of zinc oxide.

[0086] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0087] In step (1), Reax-85A was selected as the dispersant, and the mixture was ball-milled at 250 rpm for 18 h. The rest of the steps were the same as in Example 1.

[0088] Comparative Example 2:

[0089] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 10 parts of silicon dioxide, 20 parts of magnesium oxide, 50 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 0.5 parts of tantalum oxide, 3 parts of titanium oxide, and 2 parts of zinc oxide.

[0090] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0091] In step (1), Reax-85A is selected as the dispersant, and in step (2), chlorine is replaced by nitrogen, and the rest is the same as in Example 1.

[0092] Comparative Example 3:

[0093] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 20 parts of silicon dioxide, 34 parts of magnesium oxide, 42.5 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 0.5 parts of tantalum oxide, 2 parts of titanium oxide, and 1 part of zinc oxide.

[0094] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0095] Same as Example 1.

[0096] Comparative Example 4:

[0097] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 10 parts of silicon dioxide, 32 parts of magnesium oxide, 40 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 0.5 parts of tantalum oxide, 3.5 parts of titanium oxide, and 1.5 parts of zinc oxide.

[0098] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0099] In step (2), chlorine gas is replaced by nitrogen gas, and the rest is the same as in Example 1.

[0100] Comparative Example 5:

[0101] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 30 parts of silicon dioxide, 20 parts of magnesium oxide, 25 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 1 part of tantalum oxide, 4 parts of titanium oxide and 2 parts of zinc oxide.

[0102] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0103] Same as Example 1.

[0104] Comparative Example 6:

[0105] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 20 parts of silicon dioxide, 30 parts of magnesium oxide, 25 parts of aluminum oxide, 17.5 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 0.5 parts of tantalum oxide, 6 parts of titanium oxide, and 4 parts of zinc oxide.

[0106] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0107] Same as Example 1.

[0108] Comparative Example 7:

[0109] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 10 parts of silicon dioxide, 39 parts of magnesium oxide, 32.5 parts of aluminum oxide, 17.5 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 0.5 parts of tantalum oxide, 3.5 parts of titanium oxide, and 1.5 parts of zinc oxide.

[0110] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0111] In step (2), chlorine gas is replaced by nitrogen gas, and the rest is the same as in Example 1.

[0112] Comparative Example 8:

[0113] An aluminum-magnesium spinel ceramic comprises the following raw materials in parts by weight: 30 parts of silicon dioxide, 24 parts of magnesium oxide, 20 parts of aluminum oxide, 17.5 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 1 part of tantalum oxide, 2 parts of titanium oxide, and 1 part of zinc oxide.

[0114] A method for preparing aluminum-magnesium spinel ceramics comprises the following steps:

[0115] Same as Example 1.

[0116] Test example

[0117] 1. Insulation resistance

[0118] The aluminum-magnesium spinel ceramics prepared in Example 1 and Comparative Examples 1-8 were subjected to insulation resistance measurement according to GJB1217A-2009 method 3003 at room temperature 26°C, humidity 45.5% and atmospheric pressure 99 kPa. The results are shown in Figure 2 .

[0119] Depend on Figure 2 It can be seen that the insulation resistance of the aluminum-magnesium spinel ceramics of Example 1, Comparative Example 5 and Comparative Example 8 at room temperature is significantly higher than that of the other groups. This is because the silicon dioxide content is significantly higher than that of the other groups. In addition, due to the low mass fraction of titanium oxide and zinc oxide, it is not easy to form an independent conductive phase after high-temperature sintering, which also leads to a higher room temperature insulation resistance.

[0120] The insulation resistance of the aluminum-magnesium spinel ceramics in Comparative Examples 2, 4 and 7 is significantly reduced. This is because chlorine can significantly reduce the sintering temperature of aluminum-magnesium spinel. The groups without chlorine treatment cannot be sintered into dense aluminum-magnesium spinel ceramics at 1400°C, and the porosity increases, resulting in lower insulation resistance.

[0121] The room temperature insulation resistance of the aluminum-magnesium spinel in Comparative Examples 6 and 7 is significantly lower than that of the aluminum-magnesium spinel in Comparative Examples 1 and 2, respectively. This is because excessive addition of magnesium oxide leads to increased micropores, reduced density, and other problems, resulting in reduced insulation resistance.

[0122] 2. Porosity

[0123] The porosity of the aluminum-magnesium spinel ceramics prepared in Example 1 and Comparative Examples 1-8 was measured according to standard ISO 18754:2020 at a temperature of 23°C, a humidity of 47.5% and an atmospheric pressure of 99 kPa. The results are shown in Figure 3 .

[0124] Depend on Figure 3 It can be seen that the porosity of the aluminum-magnesium spinel in Comparative Examples 2, 4 and 7 is significantly higher than that of the other groups. This is because chlorine does not participate in the precursor reaction, resulting in the inability to sinter at 1400°C to form dense aluminum-magnesium spinel ceramics.

[0125] The porosity of Comparative Examples 1 and 2 is smaller than that of Comparative Examples 3 and 4, respectively, and smaller than that of Comparative Examples 6 and 7, respectively, because as the molar ratio of the reactants magnesium oxide and aluminum oxide gradually increases, a dense alumina-magnesium oxide spinel phase cannot be completely formed, resulting in an increase in porosity.

[0126] It can be found that the porosity of Comparative Example 8 is abnormal, which may be due to the excessive magnesium oxide and silicon dioxide sintered at high temperature to form a dense olivine phase or pyroxene phase, which reduces the porosity.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An aluminum-magnesium spinel ceramic with high resistance, characterized in that: The invention comprises the following raw materials in parts by weight: 28-32 parts of silicon dioxide, 15-17 parts of magnesium oxide, 38-42 parts of aluminum oxide, 1-3 parts of lanthanum oxide, 2-5 parts of zirconium oxide, 1.5-2.5 parts of calcium oxide, 0.8-1.2 parts of tantalum oxide, 2-4 parts of titanium oxide and 1-3 parts of zinc oxide.

2. The aluminum-magnesium spinel ceramic with high resistance according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 30 parts of silicon dioxide, 16 parts of magnesium oxide, 40 parts of aluminum oxide, 2 parts of lanthanum oxide, 3 parts of zirconium oxide, 2 parts of calcium oxide, 1 part of tantalum oxide, 3 parts of titanium oxide and 2 parts of zinc oxide.

3. The aluminum-magnesium spinel ceramic with high resistance according to claim 1 or 2, characterized in that: The purity of silicon dioxide is ≥99.9%, and the BET particle size is 10-20nm; the purity of magnesium oxide is ≥99.9%, and the particle size is 100-300nm; the purity of aluminum oxide is ≥99.9%, and the particle size is 50-200nm; the purity of lanthanum oxide is ≥99.5%; the purity of zirconium oxide is ≥99.5%, and the particle size is 200-500nm; the purity of calcium oxide is ≥99.5%; the purity of tantalum oxide is ≥99%; The purity of zinc oxide containing titanium oxide is ≥99.5%.

4. The method for preparing the aluminum-magnesium spinel ceramic with high resistance according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) adding the raw materials to the dispersant, ball milling and mixing to obtain a slurry, drying, sieving, and obtaining a powder; (2) heating the powder obtained in step (1) to 900-1100° C., placing it in a chlorine and argon atmosphere, keeping the temperature for 1.5-2.5 h, then placing it in an argon atmosphere, cooling it to room temperature, grinding it, and sieving it to obtain a precursor powder; (3) placing the precursor powder obtained in step (2) into a mold and statically pressing to obtain a green embryo; (4) The green body obtained in step (3) is heated to 1250-1350° C. in an air atmosphere, kept at this temperature for 5-7 hours, then heated to 1380-1420° C. in an argon atmosphere at 130-170 MPa, kept at this temperature for 1.5-2.5 hours, and then cooled to room temperature to obtain an aluminum-magnesium spinel ceramic with high resistance.

5. The method for preparing the aluminum-magnesium spinel ceramic with high resistance according to claim 4, characterized in that: In step (1), the dispersant is anhydrous ethanol or Reax-85A.

6. The method for preparing the aluminum-magnesium spinel ceramic with high resistance according to claim 4, characterized in that: In step (1), the mixture is ball-milled at 200-300 rpm for 12-24 h.

7. The method for preparing the aluminum-magnesium spinel ceramic with high resistance according to claim 4, characterized in that: In step (2), the flow ratio of chlorine gas to argon gas is 1:1-2.

8. The method for preparing the aluminum-magnesium spinel ceramic with high resistance according to claim 4, characterized in that: In step (3), static pressure is applied at 150-200 MPa for 2-3 min.

9. The method for preparing aluminum-magnesium spinel ceramics with high resistance according to claim 4, characterized in that: In step (4), the temperature is raised to 1300° C. and kept at this temperature for 6 h, then raised to 1400° C. under argon gas and 150 MPa conditions, and then cooled to room temperature.

10. Application of the aluminum-magnesium spinel ceramic with high resistance as claimed in claim 1 or 2 in national defense industry or electronic packaging.

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