Method for preparing porous chromium carbide by using reaction sintering process

A chromium carbide and process technology, applied in the field of porous carbide preparation, can solve the few problems such as porous chromium carbide preparation process, and achieve the effects of strong operability and controllability, low cost, and simple process equipment

Inactive Publication Date: 2014-02-05
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Despite this, there are few published research reports on the preparation process of porous chromium carbide.

Method used

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  • Method for preparing porous chromium carbide by using reaction sintering process
  • Method for preparing porous chromium carbide by using reaction sintering process
  • Method for preparing porous chromium carbide by using reaction sintering process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Step 1. Preparation of the ceramic body:

[0028] The raw material for the preparation of the ceramic body is chromium oxide powder. The original chromium oxide powder is added to alumina balls and ground by a ball mill for 10 hours until uniform, and then 15wt. The final powder is pressed into an embryo body by cold isostatic pressing in a mold specially made by the manufacturer for subsequent use; wherein, the pressure of the cold isostatic pressing is 20MPa;

[0029] Step 2. Preparation of porous ceramics:

[0030] The green body prepared in step 1 is placed in a vacuum tube furnace for pre-sintering. The pre-sintering is to sinter the ceramic green body at a temperature of 150°C in air for one hour and then raise the temperature to 1000°C for another 2 hours;

[0031] Then feed methane 10% + argon 40% + H into the vacuum tube furnace at a flow rate of 40 ml / min 2 A mixed gas with a composition of 50% was sintered at a temperature of 1000°C for 10 hours to obtain a...

Embodiment 2

[0033] Step 1. Preparation of the ceramic body:

[0034] The raw material for the preparation of the ceramic body is chromium oxide powder. The original chromium oxide powder is added to alumina balls and ground by a ball mill for 10 hours until uniform, and then 10 wt. The final powder is pressed into an embryo body by means of cold isostatic pressing in a mold specially made by the manufacturer for subsequent use; wherein, the pressure of said cold isostatic pressing is 100MPa;

[0035] Step 2. Preparation of porous ceramics:

[0036] The green body prepared in step 1 is placed in a vacuum tube furnace for pre-sintering. The pre-sintering is to sinter the ceramic green body at a temperature of 150°C in air for one hour and then raise the temperature to 1000°C for another 2 hours;

[0037] Then, methane 20% + argon 30% + H was introduced into the vacuum tube furnace at a flow rate of 60 ml / min. 2 A mixed gas with a composition of 50% was sintered at a temperature of 1200°C ...

Embodiment 3

[0039] Step 1. Preparation of the ceramic body:

[0040] The raw material for the preparation of the ceramic body is chromium oxide powder. The original chromium oxide powder is added to alumina balls and ground by a ball mill for 10 hours until uniform, and then 5wt. The final powder is pressed into an embryo body by the method of cold isostatic pressing in a mold specially made by the manufacturer for subsequent use; wherein, the pressure of the cold isostatic pressing is 200MPa;

[0041] Step 2. Preparation of porous ceramics:

[0042] The green body prepared in step 1 is placed in a vacuum tube furnace for pre-sintering. The pre-sintering is to sinter the ceramic green body at a temperature of 150°C in air for one hour and then raise the temperature to 1000°C for another 2 hours;

[0043]Then, a mixed gas consisting of 15% methane + 35% argon + 50% hydrogen was introduced into the vacuum tube furnace at a flow rate of 80 ml / min, and sintered at a temperature of 1300°C for...

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Abstract

The invention relates to a method for preparing porous chromium carbide by using a reaction sintering process. The method comprises the following steps: adding chromic oxide powder into alumina balls; grinding for 10 hours through a ball mill till the powder is uniform; adding a binder PEG-400 (Polyethylene Glycol) and uniformly mixing; pressing the uniformly mixed powder in a die to form a blank by an isostatic cool pressing method; placing the blank in a vacuum tubular furnace; sintering for 1 hour at 150 DEG C and then heating to 1000 DEG C and sintering for 2 hours; introducing a mixed gas; and sintering for 10-20 hours at 1000-1300 DEG C to obtain a chromium carbide ceramic block material in a macroporous form. In order to prevent oxidization of porous chromium carbide at a high temperature, argon is intruded in the cooling process to chieve a protection function. According to the method provided by the invention, macroporous chromium carbide block materials in various shapes can be obtained. The method has strong operability and controllability to a microstructure of the porous material. Compared with conventional method, the method is simple, easy in forming and applicable to industrial preparation of porous ceramics.

Description

technical field [0001] The invention relates to a preparation method of porous carbide, in particular to a preparation method of porous chromium carbide and its reaction sintering. Background technique [0002] Porous ceramics have many attractive properties, such as low density, wide range of porosity, good high temperature stability, low thermal conductivity, high permeability, small specific heat capacity, etc., so they are widely used in many places, including catalytic carriers, Filters, bioreactors, batteries, gas sensors, gas separation devices, thermal insulation materials, capacitors, shock absorbers, heaters, heat exchangers, molds and surgical implants, etc. With the emergence of more and more new porous materials, they are becoming more and more important to our modern technological life. [0003] So far, many inorganic materials (oxides, carbides, etc.) have been used to prepare porous ceramics. Among them, carbide-based porous ceramics are very popular in met...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B38/06C04B35/56C04B35/622
Inventor 高克玮张雷陈卫星庞晓露
Owner UNIV OF SCI & TECH BEIJING
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