Micromechanical testing of carbon fibers deposited by low-pressure laser-assisted chemical vapor deposition Original Research Article

Carbon fibers were deposited directly from ethylene by laser-assisted chemical vapor deposition. The precursor gas pressures and the incident laser powers were varied. Micro-mechanical testing was carried out using a high-precision micro-manipulator. During three-point bend testing the fibers showed an elastic response, with no residual strain upon unloading, until fracture. The fibers’ strength and Young’s modulus are reported. A model for fiber fracture is proposed based on fiber cross-section analysis. Scanning electron microscopy was used to study the fiber cross-sections and the fiber surface morphology. The mechanical properties are related to the characteristic fiber microstructure investigated by Raman spectroscopy.