Survivability of optical fiber sensor elements embedded in silicon carbide ceramic matrix composites

摘要

Abstract: Optical fiber sensor elements were embedded in ceramic matrix composite (CMC) specimens fabricated at the Oak Ridge National Laboratory using a rapid chemical vapor infiltration (CVI) process. The silica and sapphire optical fiber sensors were placed between adjacent layers of interwoven Nicalon$+R$/ fibers during the stacking of a preform. This preform was then coated with pyrolytic carbon, used as an interface layer, and then densified with additional silicon carbide through CVI. This paper discusses the survivability of both the silica and sapphire optical fiber sensor elements, and suggests the possibility of using embedded optical fiber sensor elements inside high temperature composites for both fabrication monitoring and subsequent in-service lifetime monitoring at high temperatures. !3