中文摘要：

分别在陶瓷类ZrO2、Y2O3、BN和Al2O3坩埚内于2053K（或2153K）保温30min（或10min）重熔铌基超高温合金（主要组分为Nb、Si、Ti、Hf等），以研究该合金的高温熔体与不同材料坩埚的反应情况。实验发现Y2O3、BN和Ai2O3坩埚对熔体都发生了不同程度的沾污反应；在ZrO2坩埚壁上出现了50～60μm厚且具有微小裂纹或熔蚀坑的反应层，其内含有HfO2和TiO2，但ZrO2坩埚对熔体内部基本没有污染。在石墨坩埚上进行制备YSZ涂层的实验发现，ZrO2同石墨基体发生反应生成了ZrC0因此，据有关实验结果，可以先在石墨坩埚基体上用CVD法制备一层SiC内层，再在SiC内层上用浸涂法制备ZrO2涂层，以用于铌基超高温合金熔炼。

英文摘要：

Through re-melting Nb-based ultrahigh-temperature alloy in ZrO2 ,Y2O3 ,BN and Al2 03 crucibles at 2 053 K or 2 153 K respectively,the reaction behavior between the alloy melt and the above-mentioned crucibles was evaluated. It has been found that Y2O3 ,BN or Al2O3 crucibles contaminated the alloy melt to some extent. Although a reaction layer about 50-60μm thick and with many microcracks or etch pits exis- ted in the ZrO2 cucible wall adjacent to the melt after remelting,and HfO2 nd TiO2 as found in this layer, the ZrO2 rucible did not contaminate the alloy melt indeed. When YSZ coating was prepared directly on a graphite crucible,the reaction of ZrO2 with C took place. In order to prevent ZrO2 from reaction with C,a SiC inner layer was firstly prepared on the graphite by CVD method,and then ZrO2 coating was prepared on the SiC inner layer by soak and paint method.