Method for preparing transparent calcium fluoride ceramics

A calcium fluoride and transparent technology, which is applied in the field of non-oxide transparent ceramic preparation, can solve problems such as carburizing pollution, inability to remove carbon by heat treatment, and non-oxide transparent ceramics are easy to be oxidized, so as to improve light transmittance and eliminate carbon pollution effect

Inactive Publication Date: 2016-11-16
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Oxide transparent ceramics can burn off graphite through post-heat treatment, but non-oxide transparent ceramics are easy to be oxidized, so they cannot be decarbonized by heat treatment in the air, and carburization will still occur when the heating rate is controlled, and the addition of additives is artificially added. Without the impurity phase, it is impossible to prepare transparent ceramics with optical properties close to the theoretical value.
[0005] In summary, the use of spark plasma sintering technology to prepare transparent ceramics will produce carburizing pollution that cannot be ignored.

Method used

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  • Method for preparing transparent calcium fluoride ceramics
  • Method for preparing transparent calcium fluoride ceramics
  • Method for preparing transparent calcium fluoride ceramics

Examples

Experimental program
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Effect test

Embodiment 1

[0023] 1) Sample loading of powder raw materials: such as figure 2 , first wrap the inner wall of the graphite mold with metal molybdenum foil 1 with a thickness of 0.025mm, then put calcium fluoride powder 2 into the graphite mold 3, and wrap the outer wall of the mold with carbon felt for heat insulation;

[0024] 2) Sintering of transparent ceramics: put the graphite mold in such as figure 1 In the discharge plasma sintering furnace shown, vacuumize to 20Pa, heat up to 1100°C at 100°C / min, pressurize at 100MPa, and hold for 10min;

[0025] 3) Sample treatment: After the sample is naturally cooled, the sample is taken out, rough-ground with different types of sandpaper, and then polished on both sides with diamond polishing liquid on an automatic polishing machine to obtain a transparent calcium fluoride ceramic with a thickness of 1mm.

[0026] Such as image 3 The calcium fluoride transparent ceramic prepared by adding molybdenum foil is pure and transparent, and the wo...

Embodiment 2

[0028]1) Sample loading of powder raw materials: first wrap the inner wall of the graphite mold with metal nickel foil with a thickness of 0.025mm, then put the calcium fluoride powder into the graphite mold, and wrap the outer wall of the mold with carbon felt for heat insulation;

[0029] 2) Sintering of transparent ceramics: put the graphite mold in a discharge plasma sintering furnace, evacuate to 20Pa, heat up to 1100°C at 100°C / min, pressurize at 100MPa, and hold for 10min;

[0030] 3) Sample treatment: After the sample is naturally cooled, the sample is taken out, rough-ground with different types of sandpaper, and then polished on both sides with diamond polishing liquid on an automatic polishing machine to obtain transparent calcium fluoride ceramics.

Embodiment 3

[0032] 1) Powder raw material loading: first wrap the inner wall of the graphite mold with metal foil with a thickness of 0.025mm, then put the calcium fluoride powder into the graphite mold, and wrap the outer wall of the mold with carbon felt for heat insulation;

[0033] 2) Sintering of transparent ceramics: put the graphite mold in a discharge plasma sintering furnace, evacuate to 20Pa, heat up to 1200°C at 100°C / min, pressurize at 100MPa, and hold for 20min;

[0034] 3) Sample treatment: After the sample is naturally cooled, the sample is taken out, rough-ground with 600-grit sandpaper, and then polished on both sides with diamond polishing liquid on an automatic polishing machine to obtain transparent calcium fluoride ceramics.

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Abstract

The invention relates to a method for preparing transparent calcium fluoride ceramics. The method comprises the following steps: 1) loading powder materials, namely coating the inner wall of a graphite jig by using a metal foil, filling calcium fluoride powder into the graphite jig, and coating the outer wall of the jig by using a carbon felt so as to insulate heat; 2) sintering transparent ceramics, namely putting the graphite jig into a discharge plasma sintering furnace for sintering; and 3) performing sample treatment, namely taking out the sintered sample, coarsely grinding and polishing, thereby obtaining the transparent calcium fluoride ceramics. Compared with the prior art, the method disclosed by the invention has the advantages that with the adoption of the method disclosed by the invention, carbon pollution can be eliminated, light transmittance of the transparent calcium fluoride ceramics is improved, the maximum transmittance in an ultraviolet-visible band can be greater than 87%, and the problem in the traditional discharge plasma sintering technology that a carbon pollution sample is caused by carburization of the graphite jig at a high temperature is solved.

Description

technical field [0001] The invention relates to the field of preparation of non-oxide transparent ceramics, in particular to a preparation method of transparent calcium fluoride ceramics. Background technique [0002] The preparation process of transparent ceramics is similar to that of other functional ceramic materials. But for transparent ceramics, its preparation process has its own unique characteristics, especially in the two stages of powder raw material synthesis and ceramic sample material sintering process. The preparation of transparent ceramics requires that the pores, impurities and second impurities in the transparent ceramic samples be minimized in all aspects, which will cause scattering and absorption loss of incident light, and finally prepare transparent ceramics with high optical quality. . [0003] Among the many preparation technologies at present, hot press sintering and spark plasma sintering are the most researched due to the direct pressure in the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/553C04B35/64
CPCC04B35/553C04B35/64C04B2235/666C04B2235/9653
Inventor 涂溶王萍章嵩杨梅君张联盟
Owner WUHAN UNIV OF TECH
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