U-Mo合金成分均匀性工艺研究

Control of Homogeneity of U-Mo Alloy

对真空感应熔炼采用的石墨坩埚涂层材料及其制备工艺、合金成分均匀性控制进行了研究。结果表明：涂层选用加入5wt％-10wt％二氧化钛稳定的氧化钙材料，经真空烧结而成，将能提高其稳定性；金属钼片靠坩埚底部装料有利于成分均匀；熔炼温度在1480℃、时间8min左右，控制钼含量的成分均匀性和合金中杂质元素碳的综合效果较合适；晶粒基本上为等轴晶，晶粒等级为6．4级（35μm左右），晶粒中心钼含量要比晶粒边界要高；合金未浇注影响了合金相的组成；并形成以α-U相为主的金相结构。要保持尽可能多的亚稳γ相，必须对合金进行浇注，以加快冷却速度。

The coating of graphite crucible and its preparation technology, and homogeneity controlling for U-Mo alloy are studied when we melt U-Mo alloy in the vacuum induction furnace. The experimental results show that the material is calcium oxide stabilized by 5wt%-0wt% titanium oxide and the coating is sintered in the vacuum induction furnace, thus the stability of the coating will be improved. Molybdenum is loaded on the bottom of graphite crucible, which is helpful to control the homogeneity of U-Mo alloy. When the melting temperature is about 1480℃, and melting time is about 8 minutes, the general efficiency of the homogeneity controlling for Mo component and the carbon impurity decreasing of U-Mo alloy is good. The crystal grain is basically the equiaxial crystal, and the grade is 6.4 （about 35μm）. The content of Mo in the center of crystal grain is higher than that of grain boundary; The alloy which is not cast has effect on the phase composition of alloy, and the body is α-U. In order to keep metastable γ as much as possible, the alloy must be cast and cooled quickly.