Method for preparing carbon fiber reinforced silicon carbide (Csf/C-SiC) composite material

Abstract

The invention discloses a method for preparing a carbon fiber reinforced silicon carbide (Csf / C-SiC) composite material, wherein the method comprises the steps: (1) putting a 3-30 mm short-cut carbon fiber in a dimethylsulfoxide solution, soaking for 2 h, and degumming; (2) strongly dispersing the short-cut carbon fiber to obtain a dispersed short-cut carbon fiber; (3) placing a weighed silicon carbide (SiC) powder in an organic solvent solution, adding polycarbosilane, a silicon powder, an aluminum powder and a boron powder under stirring, and mixing to obtain a suspension; (4) heating the suspension to 80 DEG C-120 DEG C, evaporating, to obtain a block mixture, grinding the mixture, and allowing to pass through a sieve with 200 mesh or less, to obtain a mixed powder; (5) pounding and mixing the dispersed short-cut carbon fiber and the mixed powder, to obtain a slurry; and (6) placing the slurry in a mold, finalizing the design, carrying out hot pressed sintering, and thus obtaining the carbon fiber reinforced silicon carbide (Csf / C-SiC) composite material. The method can improve the densification degree of high temperature performance materials in high temperature service environments.

Description

technical field [0001] The invention relates to a preparation method of carbon fiber reinforced silicon carbide (Csf / C-SiC) composite material prepared by hot pressing and sintering process, in particular to a carbon fiber reinforced silicon carbide (Csf / C-SiC) with less residual silicon and good high-temperature friction performance. SiC) composite material. Background technique [0002] Hot pressed sintering is currently the most widely used rapid sintering method for manufacturing SiC and its composite material engineering devices. However, silicon carbide ceramics have high defect sensitivity, and insufficient toughness is considered the most fatal defect of ceramic materials, so its application range is greatly limited. [0003] At present, introducing fibers as reinforcements is an effective way to improve the toughness and strength of silicon carbide ceramic materials. However, due to the complex preparation process of continuous fiber reinforced composite materials...

AI Technical Summary

Problems solved by technology

However, there are many technical difficulties in the uniform mixing of chopped fibers and powders. The Csf / C-SiC composite material prepared by hot pressing and sintering with silicon as a sintering aid has high residual silicon, and the density of the material decreases. , especially in high temperature environment, the mechanical properties will decrease significantly

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