Ion-Irradiation Effect On High-Temperature Behaviors Of Advanced Sic Fibers

Heavy ion beam irradiation is usually chosen to simulate neutron irradiation damages in materials. However, there has the difficulty to study macro-properties of irradiated materials due to the very small affected depth. In this study, we have explored macro-properties of the ion-irradiated materials, owing to very fine diameter of Tyranno (TM)-SA SiC fibers. The fibers were irradiated at a National Large Accelerator of Heavy Ions facility, GANIL (Caen, France), under 95 MeV Xe ions at room-temperature. To prevent the damage gradient in fiber, the fibers were irradiated on two sides with two fluence levels. According to TRIM-code calculation, the irradiation damages in the fibers affected the entire volume of the fibers with estimations of 0.05 and 0.2 dpa. The high-temperature behaviors of the ion-irradiated fibers from room temperature to 1200 degrees C were investigated by a specific tensile test device of single fiber, named MacaSiC. The thermo-elastic modulus of the ion-irradiated fibers showed the recovering, which started from 600 degrees C during heating. The thermo-electrical conductivity of the ion-irradiated fibers gradually increased until 900 degrees C and then saturated during heating and gradually decreased during cooling. The normalized value of electrical conductivity for 0.05 dpa irradiated fibers had higher than that of 0.02 dpa irradiated fibers after heating and cooling.