STP345: Compressive Properties of Pyrolytic Graphite from Room Temperature to 5000 F

    Gobble, L. P.
    Supervisor and Senisor Research Engineer, Materials Test Section of Product Assurance Structural Test Services, Lockheed Missiles and Space Co., Sunnyvale, Calif.

    Salmen, W. J.
    Supervisor and Senisor Research Engineer, Materials Test Section of Product Assurance Structural Test Services, Lockheed Missiles and Space Co., Sunnyvale, Calif.

    Pages: 10    Published: Jan 1963


    Abstract

    The objective of this test was to determine the compressive properties of pyrolytic graphite when loaded parallel to the a-b planes at temperatures from room temperature to 5000 F after heating at rates of 400 F per sec. Loading was programmed at a rate of 1000 psi per sec.

    Pyrolytic graphite behaved in a brittle manner at all test temperatures. Average room temperature properties are: compressive strength, 13,500 psi; elastic modulus, 3.5 × 106 psi. The compressive strength decreased 6 per cent and the elastic modulus decreased 13 per cent in the range from room temperature to 3500 F. From 3500 to 5000 F a sharp decrease in compressive strength and elastic modulus occurred. Average properties at 5000 F are: compressive strength, 9700 psi; elastic modulus, 1.5 × 106 psi.

    The proportional limit of pyrolytic graphite at a given temperature is approximately 25 per cent of the compressive strength. Typical stress-strain curves for specimens tested up to 5000 F are presented. Special equipment and test techniques used to obtain the required properties are described.


    Paper ID: STP45101S

    Committee/Subcommittee: F07.07

    DOI: 10.1520/STP45101S


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