AUTHOR=Sajzew Roman , Limbach Rene , Wondraczek Lothar TITLE=Deformation and Fracture of Silica Glass Fiber Under Sharp Wedge-Indentation JOURNAL=Frontiers in Materials VOLUME=7 YEAR=2020 URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2020.00126 DOI=10.3389/fmats.2020.00126 ISSN=2296-8016 ABSTRACT=

Fiber or fiber tapers are the material of choice when studying the mechanical properties and intrinsic load-response of glasses at highest sample quality and experimental repeatability. However, surface curvature strongly complicates meaningful analysis using local (sharp) contact probes. Wedge-indentation provides a means for overcoming some of the problems of normal indentation on curved glass surfaces. In particular, it enables testing in comparably homogenous, two-dimensional stress fields, avoiding the effects of the sharp edges of pyramidal indenters and facilitating auxiliary in situ or ex situ structural mapping, for example, by vibrational spectroscopy. Adjusting the wedge’s opening angle, length and orientation relative to the fiber surface enables highly reproducible studies of material deformation, surface crack initiation, and effects of fiber anisotropy.