1、Determination of temperature in the process of graphitization
The temperature of carbon carbon composite material graphitization is one of the most important index during the processing. For a long time,it is basically determined by experience. In the old days,people think the temperature is the higher the better,but it’s wrong. To any carbon composite material,there is always a ideal temperature,to the resin carbon,the best temperature is 2480℃,as for the CVD carbon,pitch carbon and mixed matrix carbon,the ideal temperature is influence by the relative content,mix form and the different type and property of the carbon fiber,and the application is also need to be considered. Usually, the resin carbon can be partly graphitized at about 2500℃,as for the pitch carbon,it’s easily to be graphitized,so the 2200℃ is enough.
2、High pressure impregnation and carbonization process
During the carbon carbon composite material processing,many condition need to be considered,
such as temperature control,pressure control,the matching between temperature and pressure,the type of pitch etc.as the production cycle is very long during the processing,and so many parameters, each parameter can have a big influence on the production structure,property. The comprehensive influence is complex.
3、The relationship between content, arrangement of carbon fiber and the mechanical properties
We can choose different types of the carbon fiber according to the pressure of the parts. In a particular direction,if the fiber content is the same,the mechanical properties will be better when the fiber distribute uniformity.
4、The relationship between the density and property of the carbon carbon composite.
All the properties of carbon carbon composite material is closely related to the density.
So the density is also a key point during design,production and using. People think the higher density means higher properties,but it’s not true.as for the density,there is a ideal density,if the density is higher than it,the cost and production cycle will be higher and longer,on the other hand,it may have a negative effect to the properties of carbon carbon composite material.