High-velocity impact damage behavior of plain-woven SiC/SiC composites after thermal loading

摘要

This study investigates characteristics of foreign-object damage in plain-woven SiC/SiC composites after thermal loading. High-speed impact tests were conducted on virgin specimens, thermally exposed spec imens, and thermally shocked specimens, in which the maximum temperature during thermal loading was 600 ℃ or 1000℃. An oxide layer was generated on the specimen surface by thermal loading at 1000℃. Damaged areas on the front and back surfaces induced by particle impact were independent of thermal loading. However, in specimens thermally loaded at 1000 ℃, brittle failure, i.e. cone cracking without fiber pull-out, occurred due to oxidation of the fiber/matrix interfaces, and the ballistic limit velocity significantly decreased. Finally, the ballistic limit is predicted using static strength properties, and the effect of thermal loading on impact resistance is discussed.