High-temperature strength behavior of synroc-C

Comparative measurements have been made of the high-temperature flexure str ength characteristics of synroc-C in air and argon environments. The stress -strain curves for synroc show a large deviation from linearity with increa sing temperature in both environments, indicating a brittle-ductile transit ion. Strength is relatively constant at less than or equal to 800 degreesC, followed by a discernible increase, with a peak at similar to 920 degreesC in air and 940 degreesC in argon, and then a dramatic drop-off. The streng thening response is explored with reference to microstructural changes, in particular oxidation effects, and the implications of the observations are discussed.