Conductive ceramic material, method for preparing the same and use thereof

Abstract

The application belongs to the technical field of conductive ceramic materials, and particularly relates to a conductive ceramic material and a preparation method and application thereof. According to mass parts, the conductive ceramic material comprises the following components: 79-97 parts of beta-aluminum oxide, 0.5-2 parts of yttrium oxide, 0.7-3 parts of thorium oxide, 1-8 parts of zirconium oxide, 0.5-2 parts of molybdenum dioxide, 0.2-3 parts of copper oxide and 0.1-3 parts of zinc oxide. Due to the introduction of high-activity aluminum oxide nano powder and yttrium oxide, the sintering temperature can be greatly reduced, the energy consumption is reduced, the preparation cost is reduced, the competitiveness is improved, and the application is conducive to popularization.

Description

Technical Field

[0001] This invention belongs to the field of conductive ceramic materials, specifically relating to a β-alumina conductive ceramic material and its preparation method. Background Technology

[0002] Ceramic materials refer to a class of inorganic non-metallic materials made from natural or synthetic compounds through shaping and high-temperature sintering. They possess advantages such as high melting point, high hardness, high wear resistance, and oxidation resistance. They can be used as structural materials and cutting tool materials. Due to certain special properties, ceramics can also serve as functional materials, finding applications in new energy vehicles to address urban air pollution. Currently, the requirements for ceramic materials used in urban environmental protection are also increasing. These materials need to have high electrical conductivity, small volume, high density, high bulk density and mechanical strength, as well as oxidation resistance and good thermal stability.

[0003] Although metallic materials also possess high electrical conductivity, they are more expensive and prone to oxidation compared to ceramic materials. Ceramic materials, on the other hand, are inexpensive, oxidation-resistant, and also exhibit high electrical conductivity, comparable to that of metals. Alternatively, ordinary alumina powder can achieve good conductivity, but its sintering temperature is very high, requiring 1650-1710℃, resulting in significant energy consumption. Summary of the Invention

[0004] To address the above problems, the present invention provides a β-alumina conductive ceramic material comprising 79-97 parts of β-alumina, 0.5-2 parts of yttrium oxide, 0.7-3 parts of thorium oxide, 1-8 parts of zirconium oxide, 0.5-2 parts of molybdenum dioxide, 0.2-3 parts of copper oxide, and 0.1-3 parts of zinc oxide.

[0005] Furthermore, β-alumina is composed of highly active alumina nanoparticles and sodium oxide.

[0006] Furthermore, sodium oxide was introduced in the form of sodium carbonate, with 91.366 parts of alumina powder and 8.634 parts of sodium carbonate.

[0007] Furthermore, the highly active alumina nanoparticles are highly active γ-alumina with a specific surface area of ​​13112 m². 2 / Kg.

[0008] This invention also provides a method for preparing the above-mentioned β-alumina conductive ceramic material, comprising the following steps:

[0009] (1) β-Al2O3 powder was ball-milled with thorium oxide, zirconium oxide, molybdenum dioxide, copper oxide and zinc oxide to obtain a slurry with a particle size of 2-3 μm;

[0010] (2) The slurry obtained in step (1) is pumped into the granulation tower by a screw pump and automatically sprayed to granulate, so as to obtain spherical particles with uniform flowability.

[0011] (3) Place the spherical particles obtained in step (2) into a dry press and press them at a pressure of 500-750 MPa to obtain green bodies;

[0012] (4) The green body obtained in step (3) is sintered at 1200℃ for 3 hours;

[0013] (5) Soak the unglazed porcelain blank obtained in step (4) in a saturated NaOH solution for 10 minutes;

[0014] (6) Dry the soaked porcelain blank obtained in step (5) at 300℃ for 0.5h;

[0015] (7) The ceramic blank obtained in step (6) is placed into the corundum crucible, and the corundum crucible is heated to 1450-1510℃ in a silicon molybdenum rod furnace and then sealed and sintered at a constant temperature for 5 hours to obtain β-alumina conductive ceramic.

[0016] (8) Cut the β-alumina conductive ceramic material obtained in step (7) into thin sheets by wire cutting.

[0017] The present invention has the following beneficial effects:

[0018] This invention utilizes highly active alumina powder and doped yttrium oxide to significantly reduce sintering resistance during high-temperature sintering, promoting grain development and thus facilitating dense sintering. Furthermore, the addition of yttrium oxide to the reaction system causes yttrium ions to partially replace aluminum ions, resulting in lattice distortion and further promoting dense sintering. This significantly reduces the sintering temperature (by 200°C), lowers energy consumption, reduces manufacturing costs, enhances competitiveness, and facilitates widespread adoption. In addition, without yttrium oxide, Na ions move relatively freely only between Al-O-Al bonded spinel blocks. With yttrium oxide doping, because the ionic radii of Y ions (0.088 nm) and Al ions (0.053 nm) are closer, Y ions partially replace Al ions, allowing Na ions to move more freely between Al-O-Al and Al-OY bonded spinel blocks, resulting in better electrical conductivity. Detailed Implementation

[0019] Various exemplary embodiments of the present invention are now described in detail. Unless otherwise specified, the methods used in the embodiments are conventional methods, and the reagents used are commercially available reagents or reagents prepared using conventional methods. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0024] This invention discloses a β-alumina conductive ceramic material, comprising, by weight, the following components: 79-97 parts β-alumina powder, 0.0-0.5 parts yttrium oxide, 0.7-3 parts thorium oxide, 1-8 parts zirconium oxide, 0.5-2 parts molybdenum dioxide, 0.2-3 parts copper oxide, and 0.1-3 parts zinc oxide; wherein the β-alumina is synthesized by calcining highly active alumina powder and sodium carbonate at 1050℃ for 3 hours. The purity of the alumina, yttrium oxide, thorium oxide, zirconium oxide, molybdenum dioxide, copper oxide, zinc oxide, and sodium carbonate is all 99.9%.

[0025] The steps are as follows:

[0026] (1) β-Al2O3 powder was ball-milled with yttrium oxide, thorium oxide, zirconium oxide, molybdenum dioxide, copper oxide and zinc oxide to obtain a slurry with a particle size of 2-3 μm;

[0027] (2) The slurry obtained in step (1) is pumped into the granulation tower by a screw pump and automatically sprayed to granulate, so as to obtain spherical particles with uniform flowability.

[0028] (3) Place the spherical particles obtained in step (2) into a dry press and press them at a pressure of 500-750 MPa to obtain green bodies;

[0029] (4) The green body obtained in step (3) is sintered at 1200℃ for 3 hours;

[0030] (5) Soak the unglazed porcelain blank obtained in step (4) in a saturated NaOH solution for 10 minutes;

[0031] (6) Dry the soaked porcelain blank obtained in step (5) at 300℃ for 0.5h;

[0032] (7) The ceramic blank obtained in step (6) is placed into the corundum crucible, and the corundum crucible is heated to 1450-1510℃ in a silicon molybdenum rod furnace and then sealed and sintered at a constant temperature for 5 hours to obtain β-alumina conductive ceramic.

[0033] (8) Cut the β-alumina conductive ceramic material obtained in step (7) into thin sheets by wire cutting.

[0034] The following detailed description is based on specific embodiments.

[0035] Example 1

[0036] (1) Take 97 parts of coarse β-alumina powder, 0.1 parts of yttrium oxide, 0.7 parts of thorium oxide, 1 part of zirconium oxide, 0.5 parts of molybdenum dioxide, 0.2 parts of copper oxide and 0.1 parts of zinc oxide. Add the above components, ball milling media and deionized water into a ball mill and mix and mill for 8 hours. The mass ratio of the three components is 1:4:2, and a slurry with a particle size of 2-3 μm is obtained. The ball milling media are φ5-φ15 zirconium oxide balls.

[0037] (2) The slurry obtained in step (1) is pumped into the granulation tower by a screw pump and automatically sprayed to granulate, so as to obtain spherical particles with uniform flowability; the particle size of the spherical particles is 100 mesh (0.149 mm).

[0038] (3) The spherical particles obtained in step (2) are placed in a 100T dry press and pressed at a pressure of 550MPa to obtain green blanks.

[0039] (4) The green body obtained in step (3) is sintered at 1200℃ for 3 hours;

[0040] (5) Soak the unglazed porcelain blank obtained in step (4) in a saturated NaOH solution for 10 minutes;

[0041] (6) Dry the soaked porcelain blank obtained in step (5) at 300℃ for 0.5h;

[0042] (7) The ceramic blank obtained in step (6) is placed into the corundum crucible, and the corundum crucible is heated to 1450-1510℃ in a silicon molybdenum rod furnace and then sealed and sintered at a constant temperature for 5 hours to obtain β-alumina conductive ceramic material.

[0043] (8) The β-Al2O3 ceramic obtained in step (7) is cut into thin slices by wire cutting.

[0044] The sheet obtained by the above steps was tested and found to have a conductivity of 0.058 Ω·cm.

[0045] The formulation of this invention does not contain heavy metals such as lead, chromium, and mercury, meaning that this invention provides an environmentally friendly ceramic that meets the requirements of green environmental protection and pollution-free production. Furthermore, it complies with the latest EU lead-free standards and the stringent RoHS and WEEE standards for waste electrical and electronic equipment (WEEE) labeling, making it suitable for application in automotive, electronics, and battery products.

[0046] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

[0047] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A β-alumina conductive ceramic material, characterized in that, The components include 79-97 parts of β-alumina, 0.5-2 parts of yttrium oxide, 0.7-3 parts of thorium oxide, 1-8 parts of zirconium oxide, 0.5-2 parts of molybdenum dioxide, 0.2-3 parts of copper oxide, and 0.1-3 parts of zinc oxide.

2. The β-alumina conductive ceramic material according to claim 1, characterized in that, β-alumina is composed of highly active alumina nanoparticles and sodium oxide.

3. The β-alumina conductive ceramic material according to claim 2, characterized in that, Sodium oxide was introduced in the form of sodium carbonate, with 91.366 parts of alumina powder and 8.634 parts of sodium carbonate.

4. The β-alumina conductive ceramic material according to claim 2, characterized in that, The highly active alumina nanopowder is highly active γ-alumina with a specific surface area of ​​13112 m². 2 / Kg.

5. The method for preparing the β-alumina conductive ceramic material as described in claim 1, characterized in that, Includes the following steps: (1) β-Al2O3 powder was ball-milled with yttrium oxide, thorium oxide, zirconium oxide, molybdenum dioxide, copper oxide and zinc oxide to obtain a slurry with a particle size of 2-3 μm; (2) The slurry obtained in step (1) is pumped into the granulation tower by a screw pump and automatically sprayed to granulate, so as to obtain spherical particles with uniform flowability. (3) Place the spherical particles obtained in step (2) into a dry press and press them at a pressure of 500-750 MPa to obtain green bodies; (4) The green body obtained in step (3) is sintered at 1200℃ for 3 hours; (5) Soak the unglazed porcelain blank obtained in step (4) in a saturated NaOH solution for 10 minutes; (6) Dry the soaked porcelain blank obtained in step (5) at 300℃ for 0.5h; (7) The ceramic blank obtained in step (6) is placed into the corundum crucible, and the corundum crucible is heated to 1450-1510℃ in a silicon molybdenum rod furnace and then sealed and sintered at a constant temperature for 5 hours to obtain β-alumina conductive ceramic. (8) Cut the β-alumina conductive ceramic material obtained in step (7) into thin sheets by wire cutting.