SYNTHESIS AND FABRICATION OF REFRACTORY URANIUM COMPOUNDS. First Quarterly Report, March 1 through May 31, 1961

Activities in a program to obtain UC pellets of maximum density for irradiation testing are described. A study was made of the effects of the UC powder thermal history, sintering time, sintering temperature, and additives on the UC sinterability. Preliminary results indicate that the UC powder synthesized under the most severe conditions of temperature and time (1740 deg C, 107 min) was less sinterable than powders prepared at lower temperatures, or at the same temperature for shorter time. It was also concluded that although both temperature and time of sintering pellets affect density, temperature is more important. Additions of Fe (0.1 to 1.0%) improve sinterability and promote grain growth. The final density obtained on sintering in a vacuum was about the same as that resulting from sintering in He at atmospheric pressure. (J.R.D.