中文摘要：

以Ti47Al二元合金为研究对象，探讨了硼添加及冷却速度对合金a→y＋6c2相变的影响规律。结果表明，添加0．5at％B显著细化了Ti47A1合金的片层团组织，Ti47Al合金中块状组织主要在原始a晶界上形核，还有少量的在晶内形核；添加硼可以促进块状转变的发生，这是由于硼化物有效细化了原始口晶粒，还与固溶的硼元素有关。添加硼可以提高片层组织形成的临界冷速，抑制羽毛状组织和魏氏组织的形成。

英文摘要：

Samples of Ti47A1 and Ti47A10.5B with different cooling rates from the a single phase region have been investigated in order to understand the influence of boron addition and cooling rate on phase transformation. The results show that the addition of boron can effectively refine the lamellar colony. The massive microstructure nucleates mainly at the grain boundaries of original a grain and a little in the inner of original a grain in Ti47A1 alloy. Boron addition could promote the a to γm massive transformation during water quenching, this is due to the considerable effect of boron on refinement of the a grain size and also related to boron in solution. During OQ and AC boron could promote the a to lamellar transformation and suppress forming of the a to feathery structure and Widmanstatten structure because of increasing the critical cooling rate to obtain the lamellar microstructure.