Light Ion Irradiation Creep of SCS-6 Silicon Carbide Fibers in the Temperature Range 450 – 1100°C

Abstract

AbstractCreep tests were conducted in torsion on Textron SCS-6™ silicon carbide (SiC) fibers during irradiation with light ions in the temperature range 450-1100°C up to doses of 0.06 dpa. The fibers, produced by chemical vapor deposition (CVD), should be representative of a SiC/SiC composite matrix produced by chemical vapor infiltration (CVI).For temperatures between 450 and 600°C, the irradiation creep curves were characterised by long lasting strain transients during which the creep rate slowed down before reaching approximately steady state values. On a decrease in temperature the creep rate increased.For temperatures between 900 and 1100°C, the transient creep regime was negligible. The creep rates reached constant values shortly after starting the irradiation and increased with temperature. The activation energy was E = 0.55±0.15 eV.The results are discussed in terms of concentration and mobility of point defects and the change of these quantities with temperature.