Rapid low-temperature preparation method for Y-alpha-SiAlON transparent ceramics

A transparent ceramic and fast technology, applied in the field of transparent ceramic material preparation, can solve the problems of high sintering temperature, long sintering temperature holding time, slow time-consuming, etc., to improve the nucleation density, promote the densification process, and prevent the microstructure change. Effect

Active Publication Date: 2014-04-30
DALIAN MARITIME UNIVERSITY
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AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems of slow and long densification process in the preparation process of transparent α-SiAlON ceramics, long holding time at sintering temperature and high sintering temperature without adding additional sintering aids, the present invention provides a transparent Y-α - A rapid low-temperature preparation method for SiAlON ceramics, which can effectively promote the densification process of Y-α-SiAlON ceramics, thereby greatly shortening the holding time and effectively reducing the sintering temperature

Method used

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  • Rapid low-temperature preparation method for Y-alpha-SiAlON transparent ceramics

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Experimental program
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Effect test

Embodiment 1

[0029] ① Ingredients: According to the molecular formula Y of Y-α-SiAlON m / 3 Si 12-(m+n) Al m+n o n N 16-n Calculation of Raw Powder Si 3 N 4 , AlN, Al 2 o 3 and Y 2 o 3 The matching ratio, where m=1.2, n=1.1, namely: Si 3 N 4 : 77.3wt.%, AlN: 15.1wt.%, Al 2 o 3 : 0.2wt.%, Y 2 o 3 : 7.4wt.%.

[0030] ②Preparation of superfine mixed powder: Si 3 N 4 , AlN, Al 2 o 3 and Y 2 o 3 Put 40g of the mixed powder into a polytetrafluoroethylene ball mill jar, add 220g of 10mm, 8mm and 5mm silicon nitride balls prepared according to the mass ratio of 1.3:1:1.7, then add 110g of absolute ethanol, and put it on the planetary ball mill with Mix at a speed of 250r / min for 24 hours to refine the mixed powder and mix evenly. The particle size distribution test results of the prepared ultrafine powder are shown in figure 1 , the microscopic morphology of the mixed powder is shown in figure 2 . The average particle size of the obtained powder is 0.21 μm, and the particle...

Embodiment 2

[0038] According to the method of Example 1, the difference is that the sintering temperature is 1800°C, and the densification process is completed when the sample is kept at 1800°C for 2 minutes, and the densification time is 14.7 minutes. down to 1620°C. The density of transparent ceramics is 99.69%; XRD results are shown in image 3 (b), is the pure phase of α-SiAlON; the microstructure see Figure 4 (b), the crystal grain morphology is equiaxed crystal and columnar crystal with small aspect ratio; the photo of 1.2mm thick transparent Y-α-SiAlON ceramic is shown in Figure 5 (b), the words below the sample are clearly visible; the infrared transmittance curve of the 1.2mm thick sample is shown in Figure 6 (b), the maximum infrared transmittance is 58%.

Embodiment 3

[0040] According to the method of Example 1, the difference is that the sintering temperature is 1850 ° C, and the densification process has been completed at 1850 ° C. The densification time is 14.3 minutes. After the heat preservation is completed, the maximum pressure of 25 MPa is maintained until the temperature drops to 1650°C. The density of transparent ceramics is 99.70%; XRD results are shown in image 3 (c), is the pure phase of α-SiAlON; the microstructure see Figure 4 (c), the grain morphology is equiaxed crystal and columnar crystal; 1.2mm thick transparent Y-α-SiAlON ceramic photo is shown in Figure 5 (c), the words below the sample are clearly visible; the infrared transmittance curve of the 1.2mm thick sample is shown in Figure 6 (c), the maximum infrared transmittance is 58%.

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Abstract

The invention relates to a rapid low-temperature hot-pressing sintering method for transparent Y-alpha-SiAlON ceramics, and belongs to the field of transparent ceramic material preparation. The method comprises the following steps: firstly, batching on the basis of an alpha-SiAlON composition design, preparing ultrafine mixed powder by adopting a planetary ball mill, and preparing the transparent Y-alpha-SiAlON ceramics by utilizing the obtained ultrafine mixed powder by adopting the technologies of high-temperature slow pressurizing and cooling with pressure, high-temperature rapid nitrogen-filling, high-temperature rapid heating and rapid cooling. According to the method, the densification process of the alpha-SiAlON ceramics is greatly promoted by adopting the technology of preparing the transparent Y-alpha-SiAlON ceramics by the ultrafine mixed powder, the sintering time is effectively shortened, the sintering temperature is remarkably reduced, and the rapid low-temperature sintering of the alpha-SiAlON ceramics is realized.

Description

technical field [0001] The invention relates to a rapid low-temperature preparation method of α-SiAlON transparent ceramics, in particular to a rapid low-temperature hot-pressing sintering method of transparent Y-α-SiAlON ceramics, and belongs to the technical field of transparent ceramic material preparation. Background technique [0002] α-SiAlON has good comprehensive properties, such as high hardness, friction resistance, corrosion resistance, etc., and also has good light transmission. It is an excellent structural functional material and a very potential high temperature resistant window material. . [0003] α-SiAlON is Si 3 N 4 solid solution, the crystal structure is still a hexagonal structure. Compared with oxide transparent ceramics, α-SiAlON has better thermal stability, thermal shock resistance and oxidation resistance. Compared with other non-oxide-based transparent materials, the stabilizer of α-SiAlON is formed during sintering The instantaneous liquid ph...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/599C04B35/622
Inventor 单英春王光徐久军
Owner DALIAN MARITIME UNIVERSITY
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