Dynamic mechanical behavior of stress-graphitized pyrolytic carbon following reactor irradiation at 77°K

• Published in: Carbon (New York) 1969, Vol.7 (3), p.345-354
• Main Authors: Blankenhorn, P.R., Kline, D.E.
• Format: Article
• Language: English
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/0008-6223(69)90121-3

Stress-graphitized pyrolytic carbon specimens were subjected to reactor irradiation (~ 10 15 nvt - fast) while their temperature was maintained near 77°K. The specimen temperature was subsequently held near 77°K while the specimens were transferred into a testing apparatus where the dynamic mechanical properties (DMP) were obtained as a function of temperature from 80° to 750°K. First DMP tests after irradiation between 100° and 300°K revealed an inverse annealing effect in the dynamic elastic modulus with an inflection near 160°K. Internal friction peaks at 180° and 240°K were also observed in this temperature region. Following annealing of the specimens to 300°K, results for both the internal friction and the elastic modulus changed, compared to the first post-irradiation run. The dynamic mechanical behavior from 100° to 750°K, as determined by the latter tests, appeared to be similar to results previously reported by Taylor, Kline and Walker for room temperature irradiations. This included a large inverse annealing peak in the elastic modulus centered slightly above 500°K.