کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1446691 | 988623 | 2012 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Microstructural control of TiAl–Nb alloys by directional solidification Microstructural control of TiAl–Nb alloys by directional solidification](/preview/png/1446691.png)
The lamellar microstructure of TiAl–Nb alloys with and without low boron additions is controlled using double directional solidification (DS). In alloys without the addition of boron, the β phase is seeded during double DS. Complete peritectic transformation occurs in both the dendritic and interdendritic regions, which can lead to the successful alignment of both the high-temperature α phase and the lamellar microstructures. Well-aligned lamellar microstructures can be easily achieved if the alloy composition is close to the peritectic point on the hypo-peritectic side. In alloys with low boron additions, however, the competitive growth of the α phase breaks the continuity of the lamellar microstructure in the region ahead of stable growth, which finally results in columnar grain coarsening and unsuccessful alignment of the lamellar microstructures.
Journal: Acta Materialia - Volume 60, Issue 2, January 2012, Pages 498–506