ION ETCHING OF AMORPHOUS AND SEMICRYSTALLTNE FIBERS

摘要

Ion etching of amorphous and semicrystalline polymeric or graphite fibers produces structures which can be observed in either the transmission electron microscope or the scanning electron microscope. The structures so produced have previously been identified as resulting from the etching process (artifacts), or as representing characteristics of the material, or both. The artifacts can be eliminated or minimized by rotating the sample during irradiation, using a low angle of incidence, and ensuring that the temperature of the sample surface remains low. When such precautions are used, amorphous fibers and semicrystalline fibers which are not oriented remain featureless after ion etching. Oriented semicrystalline fibers, however, develop a striated structure which is oriented perpendicular to the stretch direction. These transverse structural features reflect characteristic features of drawn fibers; but the relation between these features and the lamellar spacing is unclear.