Wear of polytetrafluoroethylene: some crystallographic observations

Vijayan, Kalyani and Biswas, SK (1991) Wear of polytetrafluoroethylene: some crystallographic observations. Wear, 150 . pp. 267-273. ISSN 0043-1648

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    Abstract

    When polytetrafluoroethylene (PTFE) discs are slid against EN24 steel, a transition in wear rate occurs after approximatelv 0.1 km of sliding. In the post-transition stage, the wear rate increases steadily up to a sliding distance of approximately 3 km after which it13; stabilizes. Structural characteristics of the worn surface derived from X.ray diffraction studies indicate that in the post. transition stage, a close correlation exists between the volumetric shrinkage of the unit cell and the wear rate. The shrinkage along the crystallographic c-axis, which cali promote subsequent easy sliding of the polymer chains against each other, is iound to be nearh twice the shrinkage along the crystallographic c-axis.Increase in the average crystallite si/e initiated by the sliding process does not, however,exhibit further progressive increase with sliding. The wear debris is less dense than the bulk PTFE. X-ray data from the debris indicate a lack of long range order, a reduction in crystallite size and an enlargement of the unit cell. Scanning electron micrographs show the simultaneous presence of crystalline and less crystalline fractions in the debris.

    Item Type: Journal Article
    Additional Information: Copyright for this article belongs to Elsevier
    Uncontrolled Keywords: Post-transition stage;Crystallographic c-axis;Scanning electron microscopy;Crystals-structure;Lubricants--Solid Films;Materials testing--Wear;Crystallographic volumetric shrinkage;PTFE sliding wear testing;Wear debris packing density reduction;Polytetrafluoroethylenes; Polytetrafluoroethylene;Surface properties;Wear-sliding
    Subjects: CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
    Division/Department: Materials Science Division, Other
    Depositing User: M/S ICAST NAL
    Date Deposited: 23 Oct 2006
    Last Modified: 07 May 2012 10:56
    URI: http://nal-ir.nal.res.in/id/eprint/3096

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