Publication Date


Document Type


Committee Members

Michael Cinibulk (Committee Member), Robert E. W. Fyffe (Other), Hong Huang (Committee Member), H. Daniel Young (Advisor)

Degree Name

Master of Science in Materials Science and Engineering (MSMSE)


SiC/SiC ceramic matrix composites (CMCs) with potential applications at =2700°F (1482°C) are of significant interest to the Air Force. The high temperature performance of SiC fibers used within these composites is greatly affected by the presence of amorphous SiOC and free carbon in the fibers. Therefore quantification of this non SiC material in commercially available SiC fibers is extremely important. In this work Hi Nicalon, Hi-Nicalon Type-S, Tyranno-SA3, Cef-NITE, and Sylramic SiC fibers were studied. Changes in mass, grain size, and amorphous content were measured as a function of processing temperature and time. The amorphous material in each fiber was quantified using the Spike-In method in conjunction with Rietveld refinement. Trends in amorphous content were observed, as well as trends in grain size and crystallized fraction. Transmission electron microscopy (TEM) was used to confirm changes in fiber microstructure.

Page Count


Department or Program

Department of Mechanical and Materials Engineering

Year Degree Awarded