Nanoscale mechanical characterization of glass fibers

The hardness and elastic modulus of E- and S-glass fibers with small diameters (8 to 20 mu m) have been measured by nanoindentation. As expected, the hardness and elastic modulus of S-glass fibers was found to be greater than those of E-glass fibers. As compared with E-glass fibers, S-glass fibers exhibit higher resistance to plastic deformation. The change in diameter of E-glass fibers does not affect the hardness and elastic modulus. No change in hardness and elastic modulus across diameters was observed for both E-and S-glass fibers. The present work shows that nanoindentation is a very powerful method for studying mechanical properties of small diameter glass fibers or short glass fibers of which the mechanical properties cannot be measured in fiber form using conventional mechanical testing techniques.