氢化-去氢化法制备铀锆合金粉体

Characterization of U-10%Zr Alloy Powders by a Hydriding-Dehydriding Process

铀锆合金粉体是粉末冶金法制备核反应堆用铀合金燃料的原料。采用氢化-去氢化法制备了铀锆合金粉末,用XRD及SEM进行了微观形貌的观察。结果显示,制粉前的预处理相当重要,直接影响铀锆合金的氢化性能;随着氢化-去氢化次数的增加,吸氢量随之增加,且活化10次后,吸氢量达到稳定值;在650℃下的去氢化处理后对粉体的XRD及SEM形貌观察表明,U-10%Zr（质量分数）粉体为单纯的？相,没有相的转变,随着氢化-去氢化次数的增加,中间颗粒的粒度（100~150？m）分布所占的比例逐渐升高。

U-10wt%Zr alloy powders are the raw material of the uranium alloy fuels by a powder metallurgic process in nuclear reactor. In this work, U-10wt%Zr powders were prepared by a hydriding-dehydriding process, and the prepared powders were studied by XRD and SEM. The results show that the pretreatement of U-10wt%Zr alloy is a key issue to obtain U-10wt%Zr powders. During the hydriding-dehydriding process, the absorbed hydrogen of U-10wt%Zr alloy increases with the cycle number increasing. After 10 cycles, the absorbed hydrogen reaches a stable value. U-10wt%Zr alloy were heated to desorb the hydrogen at 650 ℃, and then U-10wt%Zr alloy powders were obtained. XRD results show that U-10wt%Zr alloy powders are still y phase, indicating that during preparation, the phase transformation process does not occur. SEM observation suggests that the particle shape of U-10 wt%Zr alloy powders is nonuniform, but particle size is less than 150 lam, while some are below 100 μm.