INFLUENCE OF THE INITIAL STATE AND RATE OF COOLING FROM THE BETA PHASE ON THE PREFERRED ORIENTATION OF URANIUM AFTER HEAT TREATMENT

摘要

In a previous paper [l] it was shown that very fine-grain structures of low-percentage uranium alloys (e.g. of the U-Fe-Al-Si type) can be obtained not only by the usual quenching procedure from the beta phase into water but also in a certain range of considerably lower cooling rates from the beta region. The dependence of the grain size on the cooling rate was in this case fairly sensitive to the chemical composition. It was also found that lower cooling rates lead to a smaller degree of preferred orientation after heat treatment, and that the dependence of the preferred orientation on the cooling rate is more or less universal, i.e. virtually independent of lower contents(up to about 500 - 1000 ppm) of alloying additives such as iron, aluminum, and silicon.