BaZrO3/Y2O3复合耐火材料制备及其与TiAl合金界面反应研究

Preparation Of BaZrO3/Y2O3 Composite Refractory And Its InteractionWith TiAl Alloy

摘要:

本文使用电熔BaZrO3耐火材料和Y2O3耐火材料复合,在1650℃保温24h烧制成坩埚,感应熔炼制备TiAl合金。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)结合能谱仪(EDS)、电感耦合等离子体原子发射光谱法(ICP-AES)和氧/氮分析仪等手段分析了复合坩埚耐火材料相结构和显微结构,研究了复合耐火材料坩埚与TiAl合金熔体界面反应。结果表明,复合坩埚耐火材料由Zr固溶Y2O3和Y掺杂BaZrO3两相组成,Y2O3的引入提高了电熔BaZrO3耐火材料稳定性。熔解侵蚀作用是复合坩埚耐火材料与TiAl合金熔体界面作用机制,但游离Al2O3仍会与分解的BaO反应生成BaAl2O4附着在坩埚内壁；熔炼制备TiAl合金锭中氧含量仅为0.0986wt.%, 与理论计算值相一致,且符合工业用TiAl合金铸锭用氧含量标准,表明了电熔BaZrO3/Y2O3是一种极有潜力的TiAl合金感应熔炼制备用耐火材料。

Abstract:

The composite refractory crucible using the fused BaZrO3 and Y2O3 was fabricated after sintering at 1650℃ for 24h, then induction melting of TiAl alloy was carried out in the crucible. By using the X-ray diffraction, scanning electron microscope combined with the energy disperse spectroscopy, inductively coupled plasma atomic emission pectrometry and O/N analyzer, the phase composition and microstructure for the composite refractory are investigated as well as the interaction between the composite crucible and TiAl alloy melt. Results reveal that the composite crucible is consisted of Y doped BaZrO3 and Y2O3(ZrO2) phases, and the introduce of Y2O3 is help to the improvement of fused BaZrO3 refractory. Dissolution-erosion is the main responsible for the interaction between the refractory and TiAl alloy melt, however, the Al2O3 in the melt reacts with the BaO leading to the generation of reactant BaAl2O4, which attaches to the inner wall of the crucible. The oxygen concentration for the prepared TiAl alloy ingot is about 0.0986wt.%, which is consistent with the calculated value for the TiAl alloy. It is also met criteria for the industrial TiAl alloy ingot, which indicates that the BaZrO3/Y2O3 composite refractory is the candidate for induction melting of TiAl alloys.