真空电磁定向凝固制备高纯TiSi_(2)和共晶Si-Ti合金的研究

Preparation of high-purity TiSi_(2) and eutectic Si-Ti alloys by vacuum electromagnetic directional solidification

为了制备高纯TiSi_(2)和共晶Si-Ti合金,研究新采用真空电磁定向凝固技术对Ti-Si合金进行了相分离与提纯。结果表明,真空电磁定向凝固技术可以有效地提纯Ti-Si合金;Fe、Mn和Al杂质通过其在固-液界面上的分凝效应去除(富集在顶部);Ca和Mg杂质由于蒸气压明显高于Si和Ti,因此可以通过真空挥发去除。Ti-56%Si合金(纯度96%)经真空电磁定向凝固后,在坩埚下部分离得到致密的TiSi_(2)合金,而上部则分离得到物相均匀的共晶Si-Ti合金。由此制备的TiSi_(2)纯度达到99.4%,共晶Si-Ti合金纯度达到99.1%(仅考虑主要杂质Fe、Mn、Ca、Mg和Al条件下)。

To prepare the high-purity TiSi_(2) and eutectic Si-Ti alloys,the vacuum electromagnetic directional solidification technique was used to separate and purify Ti-Si alloys in this study.The results show that the vacuum electromagnetic directional solidification can effectively purify the Ti-Si alloys.Fe,Al,and Mn impurities were removed through their segregation effect at the solid-liquid interface(enriched at the top).Ca and Mg impurities were removed by vacuum volatilization due to the vapor pressure being significantly higher than that of Si and Ti.After vacuum electromagnetically directed solidification of the Ti-56%Si alloy(purity 96%),the dense TiSi_(2) alloy was separated in the lower part of the crucible,and the eutectic Si-Ti alloy with a homogeneous phase was separated in the upper part.The purity of the TiSi_(2) thus prepared was 99.4%,and that of the eutectic Si-Ti alloy was 99.1%(only considering the main impurities Fe,Mn,Ca,Mg,and Al).