In situ observation of fracture interface between an individual fiber and the pyrocarbon matrix in C/C composites

Interfacial fracture between an individual fiber and the pyrocarbon matrix in carbon/carbon composites has been studied in a 300 kV high-resolution transmission electron microscope (TEM) by using an integrated TEM-atomic force microscope piezodriven holder. Force vs. displacement curves were acquired by bending a part of a carbon fiber perpendicular to the transverse section of the fiber. The process of fracture at the interface between the fibers and the pyrocarbon layer shows that the pyrocarbon possesses good deformation properties.