熔炼铀和铀合金用涂层研究进展

Progress on Coating for Metal Uranium and Its Alloys Melting

铀和铀合金用涂层不同于通常的耐高温涂层,不仅要求具有耐高温和抗热震,还要求涂层与基体和熔体之间具有化学稳定性。分析了熔炼过程中的铀和铀合金的碳污染源和污染机理。表明炉内的CO和涂层的缺陷面积是熔体碳污染的主要来源,而熔体的碳污染对涂层缺陷面积更敏感,并指出了涂层的设计要求。不同涂层材料体系和制备方法的比较表明:单层涂层不能满足高性能高质量铀和铀合金熔炼的要求;内层为阻挡层(碳化物或难熔金属W,Nb,Mo等),外层为Y2O3的复合涂层,能够满足高温铀合金的熔炼要求,是铀和铀合金用涂层的发展趋势。

The coating used in molten metal uranium and its alloys is different from usually coating for high temperature, which not only should be able endure high temperature and thermal shock, but also can＇t react among graphite, coatings and uranium alloys. The resource and mechanism of carbon contamination were analyzed during metal uranium and its alloys melting. The carbon monoxide is responsible for main carbon contamination in furnace. Uranium and its alloys was most sensitive to coating defects among all carbon contaminations. The design demand of ceramic coating was pointed out. The difference coating material systems and preparation methods were compared. The result shows that the monolayer coating can＇t suitable for the uranium and its alloys melting since high performance demanded. The multilayer coating can meet uranium and its alloys melting which include outer Y203 coating and interlayer. Usually, the interlayer may be carbide, or metal such as W, Nb or Mo et al, So it can retard carbon pervasion. The multilayer coating is development trend of coatings for uranium and its alloys melting.