Silicon nitride nanowire reinforced porous silicon carbide material and preparation method thereof

Abstract

The invention relates to a silicon nitride nanowire reinforced porous silicon carbide material and a preparation method of the silicon nitride nanowire reinforced porous silicon carbide material. The invention adopts the technical scheme as follows: taking 40-70 wt% of a silicon carbide powder, 15-35 wt% of a silicon powder, 1-5 wt% of a catalyst and 10-20 wt% of a nitrogen source as raw materials, additionally adding 20-30 wt% of deionized water, stirring to obtain a ceramic slurry; adding a foaming agent, which is 10-20 wt% of the raw materials, into the ceramic slurry, continuously stirring for 30-60 minutes to obtain a ceramic foam slurry; pouring the ceramic foam slurry into a mold, standing in a nitrogen environment, drying, demolding to obtain a ceramic body; putting the ceramic body in the nitrogen atmosphere, raising the temperature to 1100-1150 DEG C, and preserving heat; raising the temperature again to 1200-1600 DEG C, preserving heat; naturally cooling to obtain the silicon nitride nanowire reinforced porous silicon carbide material. The process is simple, the cost is low, the utilization ratio of the raw materials is high, the process is easy to control, the size of pores of a prepared product is even, the pore distribution is uniform, and the mechanical strength is high.

Description

technical field [0001] The invention belongs to the technical field of porous silicon carbide materials. Specifically relates to a silicon nitride nanowire reinforced porous silicon carbide material and a preparation method thereof. Background technique [0002] Since the development of porous silicon carbide materials in the 1970s, due to their high temperature resistance, corrosion resistance and thermal shock resistance, they have been widely used in the fields of metallurgy, chemical industry, electronics and biology. [0003] At present, the preparation of silicon nitride-bonded silicon carbide materials is mainly through the direct contact between nitrogen and silicon powder to generate silicon nitride, so that the silicon powder inside the porous silicon nitride-bonded silicon carbide product cannot fully contact with nitrogen, which not only reduces the The utilization rate of silicon powder, and the remaining silicon powder and silicon nitride form structural defec...

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Problems solved by technology

[0003] At present, the preparation of silicon nitride-bonded silicon carbide materials is mainly through the direct contact between nitrogen and silicon powder to generate silicon nitride, so that the silicon powder inside the porous silicon nitride-bonded silicon carbide product cannot fully contact with nitrogen, which not only reduces the The utilization rate of silicon powder, and the remaining silicon powder and silicon nitride form structural defects, which affect the performance of the product

For example, "a porous silicon nitride combined with silicon carbide composite ceramic material and its preparation method" (CN104926316 A) patent technology, because the silicon powder in the product is easy to cause incomplete reaction and residue, resulting in uneven internal and external structure of the product, and in Silicon nitride exists in the state of particles in composite ceramic materials, and its reinforcing effect is limited, which limits the application of the product

Another example is in the research progress of porous silicon carbide materials (Chen Yixin, Wang Richu, Wang Xiaofeng, Peng Chaoqun, Sun Yuehua. Research progress of porous SiC ceramics [J]. Chinese Journal of Nonferrous Metals, 2015, Vol. 25 (No. 8): 2146- 2156) summarized a variety of preparation methods, including particle stacking sintering method, template method, adding pore-forming agent method and direct foaming forming method, etc., but did not point out the combination of nitrogen source and foaming agent to prepare silicon nitride nanowire reinforcement Porous silicon carbide material, so the actual product obtained has uneven pore size, low mechanical strength, and poor corrosion resistance

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