Method for preparing boron carbide ceramic

A technology of boron carbide ceramics and boron powder, which is applied in the field of preparation of boron carbide ceramics, can solve the problems of high hardness and light weight of boron carbide ceramics, difficulty in meeting the requirements of purity, and unsuitability for industrial production, and achieve short sintering time and low boron-carbon ratio Variety, small grain size effect

Inactive Publication Date: 2008-09-24
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The hot isostatic pressing process is complicated and not suitable for industrial production
The hot pressing sintering temperature is high, and the product grains are large. Doping sintering can effectively reduce the sintering temperature, but it will introduce other impurity elements, which is difficult to meet the purity requirements, and will also lead to a decrease in material hardness and an increase in density, which cannot be fully It embodies the characteristics of high hardness and light weight of boron carbide ceramics

Method used

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  • Method for preparing boron carbide ceramic
  • Method for preparing boron carbide ceramic
  • Method for preparing boron carbide ceramic

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Experimental program
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Effect test

Embodiment 1

[0029] The present invention prepares the method embodiment 1 of boron carbide ceramics, concrete steps comprise:

[0030] The first step, taking by weighing elemental boron powder and graphite powder with a purity of 98% and an average particle size of 0.001 μm, the molar ratio of boron to carbon in the above raw materials is 0.5, and mixed uniformly in an agate mortar;

[0031] In the second step, put the powder prepared in the first step into a high-strength graphite mold with a maximum working pressure of 60MPa. There is graphite paper between the powder and the mold, and then send it into a spark plasma sintering equipment (Dr.Sinter1050 SPS, Sumitomo Coal MiningCo ., Tokyo, Japan), and heated to 1300°C at a heating rate of 50°C / min under vacuum conditions with a vacuum degree of 1Pa;

[0032] The third step is to take the mold out of the spark plasma sintering equipment, cool down to room temperature naturally, remove the mold, and finish the product.

Embodiment 2

[0033] The present invention prepares the method embodiment 2 of boron carbide ceramics, concrete steps comprise:

[0034] The first step, taking by weighing boric acid powder and carbon black powder with a purity of 99% and an average particle size of 0.01 μm, the molar ratio of boron to carbon in the above-mentioned raw materials is 3.0, and is uniformly mixed with a mixer;

[0035] The second step is to put the powder prepared in the first step into a high-strength graphite mold with a maximum working pressure of 80MPa. There is graphite paper between the powder and the mold, and send it to a discharge plasma sintering equipment for sintering. 1. Under the condition of pre-pressure 10MPa, the temperature is raised to 1500°C at a heating rate of 100°C / min, and the temperature is kept for 3min;

[0036] The third step is to take the mold out of the spark plasma sintering equipment, cool down to room temperature naturally, remove the mold, and finish the product.

Embodiment 3

[0037] The present invention prepares the method embodiment 3 of boron carbide ceramics, concrete steps comprise:

[0038] The first step, taking by weighing boric anhydride powder and petroleum coke powder with a purity of 99.9% and an average particle size of 0.1 μm, the boron-carbon mol ratio in the above-mentioned raw materials is 4.0, and they are uniformly mixed in an agate mortar;

[0039] The second step is to put the powder prepared in the first step into a high-strength graphite mold with a maximum working pressure of 90MPa. There is graphite paper between the powder and the mold, and send it to the discharge plasma sintering equipment for sintering. , Under the condition of pre-pressure 20MPa, the temperature is raised to 1800°C at a heating rate of 150°C / min, and the temperature is kept for 5min;

[0040] The third step is to take the mold out of the spark plasma sintering equipment, cool down to room temperature naturally, remove the mold, and finish the product. ...

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Abstract

The present invention relates to a preparation method of boron carbide ceramics. In particular, the preparation method comprises the following steps: first, boron powder and carbon powder are weighed and mixed with the molar ratio of boron and carbon equal to 0.5 to 22.5; secondly, the powder prepared in the first step is arranged in a die and transmitted to discharging plasma sintering equipment for sintering, and the temperature is raised to be between 1300 and 2200 DEG C under the vacuum conditions; thirdly, the die is taken out from the discharging plasma sintering equipment and cooled to be at the room temperature; then the die is drawn away and thus the final product is prepared. In the preparation method, the direct synthesis and densification of boron carbide are completed in one step; the powder is sintered under the vacuum conditions; and the prepared boron carbide ceramics has the advantages of high purity, variety in the ratio of boron and carbon, and high hardness.

Description

technical field [0001] The present invention relates to a method for preparing ceramics, especially a method for preparing boron carbide ceramics. Background technique [0002] Boron carbide is an important engineering material, its hardness is second only to diamond and cubic boron nitride, it has high hardness, high modulus, low density and good wear resistance, oxidation resistance, acid and alkali resistance, high temperature thermoelectricity and neutron absorbing properties. These excellent properties of boron carbide can be used as bullet-proof materials, radiation-proof materials, wear-resistant and self-lubricating materials, special acid and alkali corrosion-resistant materials, cutting and abrasive tool materials, high-temperature thermoelectric materials, atomic reactor control and shielding materials, etc., widely Used in machinery, metallurgy, chemical industry, aerospace, military and nuclear industries and other fields. [0003] The current method of produc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/563C04B35/622
Inventor 张联盟陈刚章嵩王传彬沈强罗国强
Owner WUHAN UNIV OF TECH
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