Method for preparing recrystallized silicon carbide porous ceramic by combining carbothermic reduction
A porous ceramic, recrystallization technology, applied in chemical instruments and methods, catalyst carriers, chemical/physical processes, etc., can solve the problems of high cost and high energy consumption for recrystallization of silicon carbide, and achieve high surface energy and reduce purity requirements. , the effect of reducing production costs
Inactive Publication Date: 2013-04-17
XI AN JIAOTONG UNIV
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Problems solved by technology
[0005] The purpose of the present invention is to solve the problems of high energy consumption and high cost of the existing recrystallized silicon carbide. Considering that no carbothermal reduction process is involved in the current preparation of recrystallized silicon carbide, a combination of carbothermal reduction and recrystallization is provided. Two processes of crystallization, a method for preparing low-cost, high-performance, and controllable porosity silicon carbide porous ceramics
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[0016] The present invention will be further described in detail below in conjunction with specific examples.
[0017] The composition of silicon carbide porous ceramics of the present invention is as shown in Table 1. In Examples 1 to 13 shown in Table 1, the composition content of silicon carbide is generally 30 to 80%. If it is less than 30%, it serves as the material skeleton. If there is too little silicon carbide, the strength of the material is too low and it is easy to deform and crack during sintering. If it is greater than 80%, the amount of nano-silicon carbide synthesized by carbothermal reduction is too small, which is not enough to lower the recrystallization temperature and improve the performance of the material.
[0018] Table 1 Composition and preparation process of silicon carbide porous ceramics of the present invention
[0019]
[0020]
[0021] The preparation method of the silicon carbide porous ceramics composed of the examples in Table 1, first ...
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Abstract
The invention discloses a method for preparing recrystallized silicon carbide porous ceramic by combining carbothermic reduction. The method comprises the steps of: weighing 40-70% of silicon carbide powder, 15-34% of silicon oxide powder, 3-14% of nanometer carbon black and 8-12% of phenolic resin respectively in percentage by weight, and performing wet mixing by using alcohol as a solvent to prepare mixed powder; and then, performing die forming, placing an obtained die-formed body into a sintering furnace, heating to 1400-1500 DEG C in vacuum and performing carbothermic reduction for 2-2.5hours firstly, then rapidly heating to 1800-2000 DEG C in an argon atmosphere, recrystallizing for 1-3 hours to obtain a sintered body. The silicon carbide porous ceramic disclosed by the invention can be widely applied to the fields of diesel vehicle tail gas particle collectors or catalyst carriers and the like.
Description
technical field [0001] The invention relates to a preparation method of recrystallized silicon carbide porous ceramics, which can be used for various filters, catalyst carriers, biological materials and the like. Background technique [0002] Diesel vehicles have developed rapidly in recent years, but their exhaust particulate matter emission pollution has become a bottleneck factor restricting its further development, and it is also a major factor of air pollution. A particulate filter (DPF) is currently recognized as one of the most effective after-treatment technologies. DPF is made of high-temperature-resistant porous materials, and the main materials currently used are cordierite and silicon carbide. The main material of the new generation of diesel vehicle exhaust gas cleaning system is silicon carbide-based SiC honeycomb ceramic material. This is currently the honeycomb ceramic material that can meet Euro IV and Euro V emission standards. It can remove more than 90...
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IPC IPC(8): B01J32/00C04B38/06C04B35/565C04B35/622
Inventor 杨建锋刘虎林史永贵刘荣臻鲍崇高乔冠军王继平
Owner XI AN JIAOTONG UNIV