Microstructure Evolution in the Mushy Zone of a β-Solidifying TiAl Alloy under Different Cooling Processes
Microstructure Evolution in the Mushy Zone of a β-Solidifying TiAl Alloy under Different Cooling Processes
复制标题
不同冷却过程下β凝固TiAl合金糊状区显微组织演化
DOI：
10.1002/adem.201600144
复制
发表时间：
2016
影响因子：
3.6
通讯作者：
Jinshan Li
中科院分区：
文献类型：
--
作者：
Jieren Yang;Bao Xiao;Peng Han;Hongchao Kou;Jinshan Li
在本研究中，采用一种称为糊状区域冷却控制的新方法来定制凝固铝化钛合金的微观结构。 Ti-44.5Al–4Nb–2Cr–0.1B (at%)合金通过不同工艺在糊状区进行控温冷却。凝固组织由a2/γ片状团簇、B2相和块状g相组成。研究发现，快速冷却和热循环都可以起到细化a2/γ片状团簇和减少室温脆性B2相的作用。 10次热循环后获得平均大小为28mm的a2/γ菌落。结果还表明，快速冷却可以很大程度上消除凝固微观偏析。然而，a2/γ集落在这样的等温保持过程中会不断粗化。
A novel method termed mushy zone cooling control is applied to tailor the microstructure of a bsolidifying titanium aluminide alloy in this study. Ti-44.5Al–4Nb–2Cr–0.1B (at%) alloy is subjected to temperature-controlled cooling through the mushy zone by different processes. The solidified microstructure consists of a2/γ lamellar colony, B2 phase, and massive g. It is found that both the fast.cooling and the thermal cycling can play a role in refining a2/γ lamellar colonies and in reducing B2 phase, which is brittle at room temperature. a2/γ colonies with an average size of 28mm are obtained after 10 thermal cycles. The results also show that solidification microsegregation can be largely eliminated by fast cooling. However, a2/γ colonies will continuously coarsen during such an isothermal holding process.