Behavior of Metal Matrix Composite Materials at Cryogenic Temperatures
Final rept. Aug 1988-May 1990,
NEVADA ENGINEERING AND TECHNOLOGY CORP SANTA MONICA CA
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This report lists the results of mechanical tests, specifically ultimate strength, modulus of elasticity, strain-to-failure, and proportional limit, of graphite P1006061, 25 volume percent SiC2024, and 25 volume percent B4C6061 at -300 deg F, room temperature, and 250 F. The latter two were evaluated using notch specimens. These results showed that the B4C6061 was severely damaged by a notch and that the SiC6061 was only moderately damaged however, the notch tensile at -300 deg F was only slightly lower than that at 70 F. The only effect of thermal cycling between 300 F and 250 deg F was from overaging. The Gr6061, on the other hand, was severely damaged due to warpage and face sheet cracking. The modulus of the Gr6061 is reduced at -300 deg F because the 6061 is stressed beyond the yield strength and contributes little to the modulus of the composite.
- Laminates and Composite Materials