HABIT PLANE FOR HYDRIDE PRECIPITATION IN ZIRCONIUM AND URANIUM-ZIRCONIUM

The distribution of hydrogen, in the 100-ppm range, was found to be of platelet form for Zr and 1 wt.% UZr single crystals. The habit planes for the hydride platelets in the Zr crystals were found to be (1122), (1012), and (1121) while the habit planes in the 1 wt.% U-Zr crystals were of the (1231), (1121), and 1123) types. With the exception of the (1231) plane, these have been identified as the twin planes in Zr. The effect of H on the high and low strain- rate mechanical properties of Zr was explained with reference to the findings of this investigation. (auth)