Texture characterization and mechanical properties of pyrocarbon obtained by chemical vapor deposition at 1450-1550°C

Using natural gas as carbon source, isotropic and low texture pyrocarbon was fabricated with deposition temperature range from 1450 to 1550°C. The d₀₀₂-spacing and crystal size of the pyrocarbon were derived from X-ray diffraction (XRD) and Raman spectroscopy. Fracture surface morphology and texture of the pyrocarbon were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Flexural strength was tested using three points bending test. The analysis results were applied to study the relationship among deposition temperature, microstructure and flexural strength of pyrocarbon. Elevating deposition temperature not only increased the density, crystal size, but also upgraded the texture of the pyrocarbon from isotropic to low texture. It showed that density, crystal size and texture of pyrocarbon significantly influenced its flexural strength.