Damage Effects And Mechanisms Caused By Space Environments For High Modulus Carbon Fiber/Epoxy Matrix Composite

In order to reveal the damage effects and mechanisms of space environments on high modulus carbon fiber/epoxy composites, the changes in mechanical properties and mass loss ratio of M55J/AG-80 were investigated under vacuum thermo-cycling at the interval of -100℃～+ 100℃and irradiations of proton and electrons with 160keV. FT-IR,XPS and SEM were used to characterize the microscopic structure of composite before and after irradiation.Experimental results show that in the period of 100 times thermo-cycling, with increasing the cycles of vacuum thermo- cycling, tensile strength increased obviously. Then after 100 times thermo-cycling, with the thermo-cycling times increases continully, the tensile strength of the composites descends. In the period of 50 times thermo-cycling, the bend strength and interlayer shear strength increased. After 50 times thermo-cycling, with the increases of thermo-cycling times, the bend strength and interlayer shear strength descend. After 200 times of thermo-cycling, the 0°thermal expansion modulus is almost constant, the 90°thermal expansion modulus reduces a little, which indicates that the composites has good size stability.Under the irradiation flux of 0.5×1016/cm~2, the tensile strength, bend strength and interlayer shear strength increase. Then after the 0.5×1016/cm~2 irradiation flux, the tensile strength,bend strength and interlayer shear strength descend with the irradiation flux increases. While above the 1.0×1016/cm~2 irradiation flux, with the irradiation flux increases more, the strength is almost constant. With the irradiation flux increases more, the mass loss ratio accordingly increases . After the 2.0×1016/cm~2 irradiation flux, the mass loss ratio become steady. The reason of the mass loss is attributing to the volatilization of gas adsorbed in material,solvent and small molecule come from the breakage of chemical bond.After vacuum thermo- cycling, the change of properties are mainly owing to the change of the coupling density of chemical bond and interface linking intensity, and there is not new chemic reaction. Under the effect of proton and electron irradiation, the properties is mostly correlative to the coupling density of the resin.