Mechanical and Microstructural Properties of PTFE/Al/W Composite

ORAL

Abstract

Mechanical and microstructural properties of PTFE/Al/W composites with a density up to 7.1 g/cc fabricated by cold isostatic pressing with identical weight ratios of constituents (PTFE serving as the matrix) were investigated using quasi-static and Hopkinson Bar compression tests. The ultimate compressive strengths of the PTFE/Al/W composite (7.1 g/cc) with coarse W particles was $\sim $18 MPa (quasistatic loading) and $\sim $24 MPa (dynamic loading), while more porous PTFE/Al/W composite with fine W particles (5.9 g/cc) had flow stress 24 MPa (quasistatic) and 44 MPa (dynamic). Critical strains to failure for both composites are 4-5{\%}. We attribute this unusual behavior to force chains created by small tungsten particles. Environmental scanning electron microscope revealed that the PTFE matrix was populated by a homogeneous distribution of nano-cracks and nanofibers of PTFE were observed after dropweight tests.

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Authors

  • Jing Cai

    University of California, San Diego

  • Fengchun Jiang

    University of California, San Diego

  • Kenneth Vecchio

    University of California, San Diego

  • M. Meyers

    UCSD, University of California, San Diego, UC San Diego

  • Vitali Nesterenko

    Department of Mechanical and Aerospace Engineering,University of California San Diego, CA 92093, University of California, San Diego, Dept. of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093-0411, Mechanical and Aerospace Engineering Department, University of California, San Diego, Department of Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla, California 92093-0418