Carbon fiber reinforced C-SiC composites have a series of excellent properties, such as high temperature resistance, high specific strength, high specific modulus, low thermal expansion coefficient, excellent high temperature thermodynamic stability and so on.
It also has the characteristics of high density, heat shock resistance, ablation resistance and thermal chemical stability. It is a new type of composite material with high temperature resistance and high temperature, and is also a new type of high temperature resistant material, such as aerospace, advanced energy system, high temperature heat exchange system, etc.
In the existing preparation process, molten silicon infiltration reaction method (liquid silicon infiltration, LSI) due to the short preparation period, low cost, can realize net shape forming advantages, has great potential for development, has been extensively researched at home and abroad.
It can be realized by adjusting the microstructure of the preform to control the performance of C/C-SiC composites.
By high temperature heat treatment to C fibers of may effectively, change the C / C preform pore distribution, pore size and porosity, the main reason is the surface structure of the fiber is changed by the heat treatment, surface functional groups changed, resulting in combining the strength change of the fiber / matrix interface.
Carbon fibers after heat treatment, surface containing oxygen functional groups decreased, resulting in CFRP precursor fiber / resin interface bonding strength becomes weaker, thereby increasing the porosity of C / C preform and cracks / holes were mainly distributed network, by liquid silicon infiltration of C / C-SiC composites prepared by the density increased, the increased of SiC matrix, wrapped around the carbon fiber, distribution is uniform.
