Adhesion imaging of carbon‐fibre‐reinforced materials in the pulsed force mode of the atomic force microscope

Abstract

AbstractThe microstructure and microscopic mechanical and adhesive properties of carbon‐fibre bundles infiltrated with pyrolytic carbon were investigated using a combination of different scanning force techniques. Contact mode atomic force microscopy imaging was combined with lateral force imaging and adhesion force and local stiffness imaging in the pulsed force mode of the atomic force microscope. A clear material contrast was obtained between carbon fibre and pyrocarbon matrix in the adhesion and stiffness images, as well as in the friction force images, which gives valuable information about the different microscopic properties of the fibre and matrix. The significantly higher adhesive forces determined on the fibres compared with the carbon matrix may be attributed to a higher concentration of polar groups on the fibre cross‐sections due to the high degree of orientation of the graphene layers along the fibre axis. In addition, a much higher degree of spatial variation of adhesive and frictional forces is observed within the fibre compared with the matrix, indicating a higher degree of homogeneity within the pyrocarbon matrix. The data derived from the experiments give microscopic information that is essential for a more detailed understanding of the resulting macroscopic properties of these materials. Copyright © 2002 John Wiley & Sons, Ltd.