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Submicron transparent crystal alumina ceramic possessing high linear transmittance

An alumina ceramic and light transmittance technology, applied in the field of submicron grain transparent alumina ceramics and their preparation, can solve problems such as instability, and achieve the effects of improved mechanical properties, improved mechanical properties, and excellent linear light transmittance properties.

Inactive Publication Date: 2007-01-03
韩敏芳 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to solve the above-mentioned problems in the existing transparent alumina ceramics with submicron crystal grains, the present invention proposes to use high-purity nano-alumina as raw material, add zirconia as an additive to prevent the prepared ceramics from being unstable at high temperatures, and then use conventional processes to prepare alumina ceramics. Aluminum ceramic

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] (1) Preparation of slurry: 0.2 g of yttria-stabilized nano-zirconia (yttrium oxide content is 5 wt %) is added to 100 g of nano-alumina with a purity of 99.99%, 70 grams of distilled water is added, and the pH is adjusted to 4 with nitric acid, stirring mixing to prepare a slurry;

[0032] (2) Molding:

[0033] (a1) adding 10% polyvinyl alcohol solution with a mass percentage concentration of 5% to the slurry obtained in (1), and mixing by ball milling for 24 hours to make a uniformly dispersed slurry;

[0034] (b1) sieve the slurry obtained by a1, then depressurize and remove the mixed air bubbles and dissolved gas in the slurry, and the vacuum degree is 50-200mbar;

[0035] (c1) The exhausted slurry obtained by b1 is granulated by a spray drying process, and the granulated particle size is 50 microns to obtain a powder;

[0036] (d1) The powder obtained in c1 was dry pressed at 50 MPa, and then cold isostatically pressed at 200 MPa.

[0037] (3) Pre-sintering: at a...

example 2

[0042] (1) Preparation of slurry: Add 0.2 g of yttria-stabilized nano-zirconia (yttrium oxide content is 5 wt %) to 100 g of nano-alumina with a purity of 99.99%, add 30 grams of distilled water, adjust the pH to 4 with nitric acid, add 1.2g DolapixCE64, stirred and mixed to prepare a slurry with a solid content of 60-80% by mass;

[0043] (2) Molding:

[0044] (a2) Add the slurry described in (1) to an aqueous solution of 12 to 20% by mass of methacrylamide and 2 to 6% by mass of N, N'-methylenebisacrylamide, and mix it by ball milling to form a uniform dispersion the slurry;

[0045] (b2) sieve the slurry obtained in a2, then depressurize and remove the air bubbles and dissolved gases in the slurry, with a vacuum of 50-200mbar;

[0046] (c2) Add an ammonium persulfate solution with a mass percent concentration of 5% to the degassed slurry obtained in b2, and ultrasonically disperse for 1 hour to obtain a slurry;

[0047] (d2) The slurry obtained in (c2) is poured into a m...

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Abstract

The present invention belongs to the field of transparent ceramic material technology, and is especially preparation process of submicron transparent crystal alumina ceramic possessing high linear transmittance. The transparent alumina ceramic is prepared with high purity alumina and nanometer zirconia additive, and through drying pressing and cold isostatic pressing or gel injecting to form, low temperature pre-sintering and hot isostatic pressing sintering. It has ceramic body relative density greater than 99.95 %, average crystal size not greater than 0.5 micron, Vickers hardness of 2200, bending strength of 650-800 MPa and linear transmittance at 600 nm greater than 60 %. It is suitable for use in making transparent bulletproof armoring, high temperature observation window, false teeth, etc.

Description

technical field [0001] The invention relates to a transparent ceramic material and a preparation method thereof, in particular to a submicron grain transparent alumina ceramic with high linear light transmittance and a preparation method thereof. Background technique [0002] With the widespread use of high-pressure discharge lamps such as high-pressure sodium lamps and metal chloride lamps, polycrystalline transparent alumina sintered bodies have been extensively researched and produced. In order to make these polycrystalline alumina ceramics have good light transmittance, most preparation methods use a certain proportion of additives and high-temperature sintering. Patent US4222978 uses three-component additives, patent CN86101452 uses Y, Mg, La, Zr oxide four-component additives, and patent CN1444250A uses magnesium oxide and lanthanum oxide additives to sinter in a reducing atmosphere at a temperature of 1650-1900 ° C. Although the alumina ceramics sintered by these met...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/10C04B35/622
Inventor 李伯涛韩敏芳
Owner 韩敏芳
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