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为细化铸造ＴｉＡｌ基合金的显微组织，将成分为Ｔｉ４４．９Ａｌ和Ｔｉ４４．３Ａｌ３．０Ｃｒ（摩尔分数，％）的两种合金在略高于ＴｉＡｌ共析温度的１１５０℃进行长时保温处理。结果表明，保温一定时间后，两种合金中的Ｔｉ３Ａｌ＋ＴｉＡｌ片层组织都会发生不连续粗化转变，这种转变的结果能在一定程度上细化合金的晶粒尺寸，其中Ｔｉ４４．３Ａｌ３．０Ｃｒ合金的晶粒细化效果更佳。进一步的研究表明，二元Ｔｉ４４．９Ａｌ合金中的片层组织的不连续粗化转变近似符合最大熵增率原理和Ｌｉｖｉｎｇｓｔｏｎ的稳态扩散模型，其转变控制因素为晶界扩散控制；合金元素Ｃｒ的加入，原始片间距的细化及表面预变形都会大大促进这种不连续粗化转变过程。
To refine the microstructure of TiAl-based alloy, the composition of the Ti-44.9Al and Ti-44.3Al -3.0Cr (mole fraction,%) of the two alloys at slightly higher than the Ti Al eutectoid temperature Of 1150 ℃ long heat treatment. The results show that after a certain time, the Ti3Al + TiAl lamellae in the two alloys will undergo discontinuous coarsening transformation. The result of this transformation can refine the grain size of the alloy to a certain degree, in which Ti44.3Al 3.0Cr alloy grain refinement better. Further studies show that the discontinuous roughening transformation of the lamellar structure in the binary Ti44.9Al alloy approximately agrees with the principle of maximum entropy increase and Livingston’s steadystate diffusion model, and the controlling factors for its transformation are grain boundary diffusion control. The alloy The addition of elemental Cr, the refinement of the original sheet spacing and the pre-deformation of the surface greatly contribute to this discontinuous roughening transformation.