Microstructural Change of Pitch derived Carbon Matrix in C/C Composite by Ozone Treatment on Carbon Fiber

Abstract

The effects of ozone treatment against carbon fiber on the properties of carbon fiber and on the microstructural change of pitch derived carbon matrix composite were investigated. Surface treatment of PAN based and pitch based carbon fibers were carried out by using 4% ozone at 110°C 8 hours. Surface oxidation was proceeded continuously, and it was recognized that fine ditches and functional groups were introduced on the fiber, however obvious degradation of tensile strength was not observed. Surface treatment increased the bonding strength between fiber and pitch derived carbon matrix, then debonding or pealing off was not observed. High density and low contents of closed pore were attained. Especially, in cas of pitch derived carbon fiber it was difficult to distinguish the carbon fiber and the matrix carbon.