Comparison of directional solidification of γ-TiAl alloys in conventional Al2O3 and novel Y2O3-coated Al2O3 crucibles
Comparison of directional solidification of γ-TiAl alloys in conventional Al2O3 and novel Y2O3-coated Al2O3 crucibles
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DOI：
10.1016/j.jeurceramsoc.2012.11.006
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发表时间：
2013-05-01
影响因子：
5.7
通讯作者：
Zhang, Shaowei
中科院分区：
文献类型：
--
作者：
Zhang, Huarui;Tang, Xiaoxia;Zhang, Shaowei
研究了新型Y2O3涂层Al2O3(Y2O3/Al2O3)坩埚对定向凝固TiAl合金显微组织和成分的影响，并与单层Al2O3和Y2O3坩埚进行比较，在此基础上讨论了相应合金坩埚的相互作用机制。 DS 合金呈现出完全层状的 γ/α(2) 结构，其中散布着一些 Al2O3 或 Y2O3 颗粒。与使用Al2O3坩埚的情况不同，使用Y2O3/Al2O3坩埚制备的铸锭中没有发现界面相互作用层。溶解和侵蚀是合金坩埚相互作用的主要机制，随着加热温度和相互作用时间的增加而增加。然而，使用 Y2O3/Al2O3 坩埚时的相互作用程度远低于使用 Al2O3 坩埚，使得前者成为高反应性 TiAl 合金高质量 DS 的有前景的候选坩埚。 (C) 2012 Elsevier Ltd. 保留所有权利。
The effects of novel Y2O3-coated Al2O3 (Y2O3/Al2O3) crucibles on the microstructure and composition of directionally solidified TiAl alloys were investigated and compared with those of single layered Al2O3 and Y2O3 crucibles, based on which the corresponding alloy crucible interaction mechanisms were discussed. The DS alloys exhibited a fully lamellar gamma/alpha(2) structure interspersed with some Al2O3 or Y2O3 particles. Differently from that in the case of using Al2O3 crucibles, no interfacial interaction layer was found in the ingots prepared using Y2O3/Al2O3 crucibles. Dissolution and erosion were the main mechanisms responsible for the alloy crucible interactions which increased with the heating temperature and interaction time. Nevertheless, the interaction extents when using Y2O3/Al2O3 crucibles were much lower than using Al2O3 crucibles, making the former promising candidate crucibles for the high quality DS of highly reactive TiAl alloys. (C) 2012 Elsevier Ltd. All rights reserved.