铸态U-10%Mo合金的显微组织与高温力学性能

Microstructure and Elevated Temperature Mechanical Properties of Cast U-10wt%Mo Alloy

在聚变裂变混合堆概念设计中,铀钼合金除承担裂变放能的作用外,还需要作为结构材料,因此对其高温力学性能应予以关注。采用真空感应熔炼法制备了铸态U-10%Mo(质量分数)合金并进行了均匀化热处理,利用X射线衍射(XRD)、扫描电子显微镜(SEM)方法对其相结构和显微组织进行了分析,测试了样品在室温和400,500,600℃下的高温力学性能。实验发现,铸态U-10%Mo合金晶界处存在大量铀的碳化物和氧化物杂质聚集,这可能是其呈脆性沿晶断裂的原因所在。随着试验温度升高,合金的极限强度有所下降。

As a possible fuel material in fusion-fission hybrid reactor, U-Mo alloy acts as a structural material. Its mechanical properties at application temperature are of great importance. A sample of U-10wt%Mo alloy was prepared by vacuum induction melting and homogenizing annealing. XRD and SEM were used for phase and microstructure analysis. The mechanical properties of the sample at room temperature, 400, 500 and 600 ℃ were determined. Results show that there is plenty of carbide or oxide of uranium in grain boundary, which is the main cause for brittle fracture of the alloy. The ultimate strength of the sample is decreased with the test temperature increasing.