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Method for manufacturing transparent polycrystalline aluminum oxynitride

An aluminum nitride oxide, transparent technology, applied in chemical instruments and methods, nitrogen compounds, inorganic chemistry, etc., can solve the problems of high production cost and complex process, and achieve the effect of improving the sintering process

Inactive Publication Date: 2009-09-09
RES COOPERATION FOUND OF YEUNGNAM UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, there is a problem that the process is complicated and the production cost becomes high

Method used

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  • Method for manufacturing transparent polycrystalline aluminum oxynitride
  • Method for manufacturing transparent polycrystalline aluminum oxynitride
  • Method for manufacturing transparent polycrystalline aluminum oxynitride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Five aluminum oxynitride ceramic samples were fabricated under the following conditions, where Y 2 o 3 and BN (whose amounts were set at 0.08wt% and 0.02wt%, respectively) and MgO (whose amounts varied at 0, 0.05, 0.1, 0.2, and 0.3wt%) were added to Al as sintering aids 2 o 3 And AlN (65:35 molar ratio) raw material powder. The mixed raw material powder and sintering aid are passed through high-purity Al in a polyurethane container together with ethanol solvent 2 o 3 The pellets were milled for 48 hours and then dried using a rotary evaporator. The dried powder was formed into a disc of 20 mm diameter and 3 mm width using uniaxial dry pressing, and it was subsequently cold isostatically pressed. The disk-shaped sample was placed in a graphite crucible and sintered in a high-temperature electric furnace with graphite heating elements in a nitrogen atmosphere at 1 atmosphere pressure. Subsequently, it was kept at 1675°C for 10 hours and at 2000°C for 5 hours. The t...

Embodiment 2

[0053] The aluminum oxynitride ceramic sample is made using the same method as in Example 1, but the difference is that the sintering aids are 0.2wt% MgO, 0.08wt% Y 2 o 3 and 0.02wt% BN were added to each sample in the following different ways: (1) no addition; (2) addition of MgO and Y 2 o 3 ; (3) add MgO and BN; (4) add Y 2 o 3 and BN; and (5) add MgO, Y 2 o 3 and BN.

[0054] Figure 7 This is a photograph taken to compare the light transmittance of the aluminum oxynitride ceramic samples produced in this way. In the pictures from left to right you can see: (1) No sintering aid was added to this sample, (2) MgO and Y were added to this sample 2 o 3 , (3) MgO and BN are added to the sample, (4) Y is added to the sample 2 o 3 and BN, and (5) the sample is added with MgO, Y 2 o 3 and BN. In the case where MgO is not added, the transmittance is very low. Added with MgO and Y 2 o 3 Or added with MgO, Y 2 o 3 And in the case of BN, the transmittance is very hig...

Embodiment 3

[0059] Aluminum oxynitride ceramic samples were fabricated using the same method as in Example 1, but the difference was that these samples were sintered at 2000°C for 5 hours without pre-sintering. MgO was added to each sample at addition amounts of 0, 0.05, 0.1, 0.2 and 0.3 wt%, respectively.

[0060] FIG. 11 is a photograph taken to compare the light transmittance of the aluminum oxynitride ceramic samples produced in this way. In FIG. 11 , samples with MgO added in amounts of 0, 0.05, 0.1, 0.2 and 0.3 wt % are respectively from left to right.

[0061] Fig. 12 is a graph showing measured values ​​of linear light transmittance of each sample, which is measured according to wavelength. Table 3 shows the weight ratio of MgO and the average linear transmittance of these samples.

[0062] table 3

[0063] YB-b

[0064] Similar to Example 1, the light transmittance is the highest when 0.1 wt% of MgO is added. However, the light transmittance decreased by about 20%...

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Abstract

The present invention relates to a method of manufacturing a transparent polycrystalline aluminum oxynitride. Aluminum oxynitride manufactured by prior art methods has a great number of porosities therein and thus has low transparency. The present invention is directed to solving such a problem. In the method of manufacturing aluminum oxynitride of the present invention, a sintering additive added to a source powder includes less than 0.5wt.% MgO. Further, the source powder is presintered at 1550 DEG C to 1750 DEG C so that a relative density becomes 95% or more and is then resintered at 1900 DEG C or more so that a relative density higher than that of presintering can be accomplished. According to the present invention, a cubic-phased polycrystalline aluminum oxynitride ceramic can be obtained, wherein porosities therein are nearly eliminated and its substantial transparency becomes 95% or more.

Description

technical field [0001] The present invention relates generally to a method of making aluminum oxynitride ceramics, and more particularly, to a method of making polycrystalline aluminum oxynitride with high light transmission. Background technique [0002] Alumina (Al 2 o 3 ) is reduced in such a way that porosity is eliminated by atmospheric sintering of high-purity powders and grain boundaries are shortened by enlarging grains. U.S. Patent 3,026,210 discloses a method of producing transparent alumina by using less than 0.5 wt% MgO or MgO in the solid solubility limit as a sintering aid for sintering the alumina. [0003] However, although all porosity is eliminated in making alumina, the crystals of alumina become an anisotropic hexagonal phase. Therefore, since the transmitted light through alumina is affected by the orientation of crystal grains and the light diffusion at the grain boundaries is large, there is a disadvantage that the light transmittance of alumina is ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/10C04B35/111C04B35/115C01B21/072
CPCC04B35/115C04B35/10C04B35/111C01B21/072
Inventor 李在衡具本庆具教宪李国林
Owner RES COOPERATION FOUND OF YEUNGNAM UNIV
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