中文摘要：

通过电磁感应加热和液态金属冷却相结合的实验方法制备了Ti-45％Al（at％）包晶合金的定向凝固试样，并观察在不同生长速度下的微观组织和界面形态。结果发现，抽拉速度为10μm/s时，界面以胞晶形式生长。最终组织的α2＋γ片层与生长方向垂直；抽拉速度为50μm／s时，观察到明显的枝晶生长界面，α2＋γ片层与生长方向成45°角。低速下的胞状间距明显大于高速下的枝晶间距，说明快速凝固有利于减小枝晶间距。

英文摘要：

The experimental method connecting electromagnetic induction heating with liquid melting cooling was used to study microstructure and morphologies of directionally solidified Ti-45%Al （at%）peritectic alloy at different growth velocities.The results show that the interface morphology grows in cellular form when growth velocity is 10 μm/s, and the angel between the lamellar boundaries （α2＋γ） and growth direction is 90°. However, when growth velocity is 50μm/s, the crystals grow in dendritic form, and the angel between the lamellar boundaries （α2＋γ） in the grains and growth direction is 45° .The cellular spaces are bigger than dendritic spaces,which shows that the rapidly solidified process is good for minishing grain spaces in the directional solidification.