| Autor: |
Ji Zhang, Yong-juan Jing, Mingjie Fu, Fan Gao |
| Rok vydání: |
2012 |
| Předmět: |
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| Zdroj: |
Intermetallics. 27:21-25 |
| ISSN: |
0966-9795 |
| DOI: |
10.1016/j.intermet.2012.01.013 |
| Popis: |
Two-step extrusion plus subsequent heat treatment have been applied to develop a fine-grained lamellar microstructure in a pilot ingot of Ti-46Al-2.5V-1.0Cr-0.3Ni (at.%) alloy. The cast lamellar microstructure was completely broken down to an equiaxed structure after the hot deformation with an accumulated extrusion ratio of 15:1 although the severe deformation produced unfavourable γ grain bands and very thin α2 plus β strips. In the following heat treatment, conditions have been optimized to obtain the desirable amount, morphology and distribution of the β phase at elevated temperatures. The final microstructure achieved mainly consisted of lamellar colonies with an average size of 65 μm and about 5 vol% of small B2 particles. Such a refined lamellar microstructure has shown remarkable strength retention and creep resistance at high temperatures while maintaining excellent ambient ductility and fracture resistance. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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