中文摘要：

现在的工作集中了于 Ni ₃ 有一个高融化点的基于 Al 的合金。研究的目的是在微观结构和方向性地团结的 Ni-25Al 合金的机械性质上学习退却率的效果。Ni ₃ 艾尔 intermetallics 被方向性的团结(DS ) 在一个电磁的冷坩锅以不同退却率准备方向性的团结炉子。DS 样品包含 Ni ₃ 艾尔和 NiAl 阶段。主要树枝状的间距() 当退却率增加，有增加退却率(V) 的减少，和 NiAl 的体积部分分阶段执行增加。张力的测试的结果证明 DS 样品的那韧性处于退却率与减少被提高。

英文摘要：

The present work focused on the Ni_3Al-based alloy with a high melting point. The aim of the research is to study the effect of withdrawal rate on the microstructures and mechanical properties of directionally solidified Ni-25 Al alloy. Ni_3 Al intermetallics were prepared at different withdrawal rates by directional solidification（DS） in an electromagnetic cold crucible directional solidification furnace. The DS samples contain Ni_3 Al and Ni Al phases. The primary dendritic spacing（λ） decreases with the increasing of withdrawal rate（V）, and the volume fraction of Ni Al phase increases as the withdrawal rate increases. Results of tensile tests show that ductility of DS samples is enhanced with a decrease in the withdrawal rate.