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Hafnium boride-silicon carbide-graphite-tantalum silicide composite ceramic heating body and preparation method thereof

A composite ceramic and silicon carbide technology, which is used in electric heating devices, ohmic resistance heating, electrical components, etc., can solve the problems of low toughness of the heating body, poor thermal shock resistance, etc. Effect

Active Publication Date: 2016-11-09
CHUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved in the present invention is to solve the problem of low toughness and poor thermal shock resistance of the hafnium boride ceramic heating body in the prior art, by adding silicon carbide to improve the oxidation resistance, using graphite as the toughening phase, and sintering by hot pressing Method for preparing hafnium boride-silicon carbide-graphite composite ceramic heating element and its preparation method

Method used

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  • Hafnium boride-silicon carbide-graphite-tantalum silicide composite ceramic heating body and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Embodiment 1, the preparation process is as follows,

[0024] Step 1: Mixing

[0025] 83vol% hafnium boride body, 10vol% silicon carbide, 5vol% graphite, and 2vol% tantalum silicide mixed powder are used as ball milling materials, and the ball milling materials and absolute ethanol are added to the stainless steel lined with tetrachlorethylene at a volume ratio of 1:2 jar, add ZrO 2 Grinding balls (the ratio of ball to material is 4:1), the speed of the ball mill is 200r / min, and the ball milling time is 6 hours;

[0026] Step Two: Dry

[0027] In order to avoid precipitation and stratification of the mixed slurry due to density differences during the drying process, it is necessary to use a rotary evaporator to dry the mixed slurry with a drying speed of 100r / min and a drying temperature of 40°C;

[0028] Step 3: Sintering

[0029] Before loading, coat a layer of BN (boron nitride) paint on the inner wall of the mold, put the mixed powder into the graphite mold, se...

Embodiment 2

[0030] Embodiment 2, the preparation process is as follows,

[0031] Step 1: Mixing

[0032] 72vol% hafnium boride body, 15vol% silicon carbide, 10vol% graphite, and 3vol% tantalum silicide mixed powder are used as ball milling materials, and the ball milling materials and absolute ethanol are added to the stainless steel lined with tetrachlorethylene at a volume ratio of 1:2 jar, add ZrO 2 Grinding balls (the ratio of ball to material is 5:1), the rotational speed of the ball mill is 180r / min, and the ball milling time is 8 hours.

[0033] Step Two: Dry

[0034] In order to avoid precipitation and stratification of the mixed slurry due to density differences during the drying process, it is necessary to use a rotary evaporator to dry the mixed slurry with a drying speed of 40r / min and a drying temperature of 70°C.

[0035] Step 3: Sintering

[0036] Before loading, coat a layer of BN paint on the inner wall of the mold, put the mixed powder into the graphite mold, separat...

Embodiment 3

[0037] Embodiment 3, the preparation process is as follows,

[0038] Step 1: Mixing

[0039] The mixed powder of 60vol% hafnium boride, 20vol% silicon carbide, 15vol% graphite, and 5vol% tantalum silicide is used as the ball milling material, and the ball milling material and absolute ethanol are added to the stainless steel lined with tetrachlorethylene at a volume ratio of 1:2. jar, add ZrO 2 Grinding balls (the ratio of ball to material is 6:1), the speed of the ball mill is 190r / min, and the ball milling time is 7 hours;

[0040] Step Two: Dry

[0041]In order to avoid precipitation and stratification of the mixed slurry due to density differences during the drying process, it is necessary to use a rotary evaporator to dry the mixed slurry with a drying speed of 80r / min and a drying temperature of 60°C.

[0042] Step 3: Sintering

[0043] Before loading, coat a layer of BN paint on the inner wall of the mold, put the mixed powder into the graphite mold, separate the po...

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Abstract

The invention discloses a hafnium boride-silicon carbide-graphite-tantalum silicide composite ceramic heating body and a preparation method thereof. The preparation method comprises the following steps that hafnium boride, silicon carbide, graphite and tantalum silicide mixed powder is prepared from, by volume, 60%-83% of hafnium boride, 10%-20% of silicon carbide, 5%-15% of graphite and 2%-5% of tantalum silicide to serve as a ball milling material, and the ball milling material and absolute ethyl alcohol are added into a ball milling machine according to the volume ratio of 1:(1-2) to be ball-milled; mixed slurry is dried by adopting a rotary evaporator; the mixed powder is contained in a graphite mold, and the graphite mold is put into a vacuum hot-pressing furnace to be subjected to hot-pressing sintering. The heating body prepared by taking hafnium boride, silicon carbide, graphite and tantalum silicide as the main raw materials is high in compactness and using temperature, capable of achieving the highest using temperature of 2,500 DEG C in an oxidative environment, excellent in oxidation resistance and mechanical strength, not prone to fracture in the installing and using process, simple in process, short in production cycle and suitable for industrialized production.

Description

technical field [0001] The invention relates to the technical field of electric heating materials, in particular to a composite ceramic heating element and a preparation method thereof. Background technique [0002] Commonly used heating elements are silicon carbide, molybdenum disilicide and graphite. The maximum temperature of silicon carbide in the air medium is 1450°C, and the maximum temperature of molybdenum disilicide in the air medium is 1800°C. Although the temperature of graphite can exceed 2000°C, it is limited to non-oxidizing environments. The melting point of hafnium boride ceramics is 3380°C, the thermal conductivity at room temperature is about 100W / (m·k), the thermal conductivity at 1900°C is about 50W / (m·k), and the room temperature resistivity is about 1.66×10 -5 Ω·cm, it is an ideal heat-generating material in an oxidizing environment with a high temperature exceeding 1800°C. [0003] Hafnium boride mainly has two forms: monoboride and diboride, and the...

Claims

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Application Information

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IPC IPC(8): C04B35/58C04B35/645H05B3/00
CPCC04B35/58078C04B35/645C04B2235/3826C04B2235/3891C04B2235/425C04B2235/96C04B2235/9607H05B3/00
Inventor 陈亚西朱文彬王向阳任兰正郑娇玲葛秀涛郑建东
Owner CHUZHOU UNIV