The carbon carbon composite material mainly consists of carbon fiber and carbon matrix two parts. The rational design can control the strength,thermal and physical properties of the carbon carbon composite material etc. and make it meet the production requirement on the direction and dimension. The function of the carbon matrix is fix the structure and direction of the carbon perform, and make it into continuous phase,and when it is under load,the carbon matrix can transfer the load to the carbon fiber. In addition,the carbon matrix can increase the density of the carbon carbon composite material,and reduce the porosity, it can protect the perform under the ablation and oxidation environment. The carbon matrix not only can change the properties of the carbon carbon composite material,but even can control the properties of the material. So the research of carbon fiber and carbon matrix influence to the C/C composite material is very important.
As the carbon fiber arrangement and the structure of carbon matrix are different,so the carbon carbon composite has an apparent anisotropy. According to some research,the testing samples are needle felt and fine needle aspiration,the result about the ablation is: the ablation rate in the X-Y is lower than the Z direstion,it means the ablation from different direction of the C/C material is different. Under certain condition,the property of fine needle aspiration is worse than the needle felt,and the fiber density of Z axis decides the ablation ,the higher fiber content means the lower ablation,and the ablation property is better.
The different kinds of the carbon matrix also has an influence to the ablatioin property of the carbon carbon composite material. The carbon matrix kinds devide into resin base,pitch base,and pyrolytic base etc.and mixed base. With the density of pyrolytic carbon increasing, the thermal conductivity and the strength property will increase accordingly.