Porous alumina ceramic plate, and preparation method thereof

Abstract

The invention discloses a preparation method of a porous alumina ceramic plate. The preparation method comprises following steps: 1, a slurry is prepared, wherein alumina powder, a sintering aid, a solvent, a dispersant, a plasticizer, and a binder are subjected to ball milling, and are mixed uniformly so as to obtain a slurry; 2, tape casting is carried out, wherein the slurry obtained in step 1is subjected to vacuum stirring defoaming, and is subjected to tape casting so as to obtain a ceramic blank; and 3, sintering is carried out, wherein the ceramic blank obtained in step 2 is subjectedto drying, thermal insulation degumming, sintering, and cooling so as to obtain the porous alumina ceramic plate. The porous alumina ceramic plate is low in preparation cost, high in porosity, and smooth in surface.

Description

technical field [0001] The invention relates to a ceramic plate and a preparation method thereof, in particular to a porous alumina ceramic plate and a preparation method thereof. Background technique [0002] Porous alumina ceramic plates mainly play a certain role in pressure and insulation during sintering of chip ceramics, and are also generally called ceramic cover plates or insulation sheets. The existing production process of fire-proof tablets is mainly dry pressing molding: granulation→adding appropriate amount of additives to mix to make a billet to be pressed→selecting a suitable mold→adjusting pressing parameters→pressing molding→demolding→drying→sintering. [0003] However, dry press molding has the following disadvantages: (1) The particle size of the powder used in dry press molding is relatively large (2-6 μm), and the combination between the particles after molding is relatively loose, resulting in a low degree of smoothness on the surface of the green body ...

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Problems solved by technology

[0003] However, dry press molding has the following disadvantages: (1) The particle size of the powder used in dry press molding is relatively large (2-6 μm), and the combination between the particles after molding is relatively loose, resulting in a low degree of smoothness on the surface of the green body and sintering. After that, the surface is rough (roughness>7μm), and due to the poor bonding force between the particles, the porcelain-made fireproof sheet is easy to drop particles after a period of use; (2) Since the green body formed by dry pressing has no toughness, it cannot be made Thinner blanks are obtained, so the interfired sheets obtained by this molding method are relatively thick (2-4mm in thickness) and heavy in weight (100-200g); if the weight is to be reduced, subsequent grinding and polishing must be carried out.

However, due to the high hardness of the fire barrier itself, it is difficult to polish, and the polishing process is likely to cause damage to the surface of the fire barrier and the particles to fall off. Therefore, the lightest weight of the fire barrier in the existing market can only be around 90g , can no longer go down; (3) The internal compactness of the green body formed by dry pressing is inconsistent, cracking is easy to occur during the sintering process, and the surface flatness is also poor. High; (4) The porosity is obtained by adding a pore-forming agent. After the organic compound is sintered, the gas is discharged to form pores. The size distribution of the pores obtained in this way is uneven, and the process of gas discharge is easy to cause cracking of the ceramic sheet, and the surface is porous and uneven.

[0004] Therefore, the porous alumina ceramic plates in the existing market generally have a rough surface and are easy to drop particles.

At the same time, the thickness is thick and the weight is heavy. The only way to reduce the weight is through subsequent polishing. Not only the cost of polishing is high, but even if it is polished, it is difficult to achieve lighter quality and surface roughness.

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