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对利用非自耗电弧熔炼设备得到的Ti-46Al,Ti-46Al-0.3B,Ti-46Al-0.5B,Ti-46Al-2Fe,Ti-46Al-2Fe-0.3B和Ti-46Al-2Fe-0.5B合金的凝固组织进行了研究。结果表明,铸态TiAl基合金的宏观组织为典型的柱状晶组织,而且平均柱状晶直径随着Fe和B元素的加入显著减小。其中,Ti-46Al-2Fe-0.5B合金的柱状晶直径最小。B元素可以显著地细化TiAl基合金的柱状晶组织和枝晶组织,这主要是由于B元素的添加可以显著增加固液界面前沿的成分过冷度从而细化TiAl基合金的凝固组织。而且,Fe元素的添加还可以显著地提高B元素对TiAl基合金的柱状晶组织的细化效果。
Ti-46Al-0.3B, Ti-46Al-0.5B, Ti-46Al-2Fe, Ti-46Al-2Fe-0.3B and Ti-46Al-2Fe- 0.5B alloy solidification organization has been studied. The results show that the macrostructure of as-cast TiAl-based alloy is typical columnar crystal structure, and the average columnar crystal diameter decreases with the addition of Fe and B elements. Among them, Ti-46Al-2Fe-0.5B alloy columnar crystal diameter is the smallest. B element can remarkably refine the columnar crystal structure and dendritic structure of TiAl-based alloy, which is mainly due to the addition of B element can significantly increase the undercooling of the front of the solid-liquid interface to refine the solidified structure of TiAl-based alloy. Moreover, the addition of Fe element can also significantly improve the refining effect of B element on the columnar crystal structure of the TiAl-based alloy.