کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10155785 | 1666362 | 2019 | 15 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
An innovative method for the microstructural modification of TiAl alloy solidified via direct electric current application
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
شیمی مواد
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Ti-48Al-2Cr-2Nb alloy solidified with the application of direct electric current has a refined and homogeneous microstructure without segregation. We observed an initial decrease followed by a subsequent increase in grain size and lamellar spacing, with the increase in current density. Similar trend can also be obtained by varying the amount of α2-phase (Ti3Al). Using a directional solidification processing method, the columnar crystal microstructure transforms into an equiaxed crystal microstructure at a current density of 32-64âmA/mm2. High dislocation density is also introduced with a minimum cross-sectional grain size of 460âμm at a current density of 64âmA/mm2. The application of electric current alters the free energy of the critical nucleus and temperature via joule heating, causing a transformation from a columnar grain microstructure into an equiaxed grain microstructure. The increase in current density leads to a rise of the nucleation rate, and a resulting undercooling combined with temperature gradient contribute to growth of the primary phase, which finally results in grain coarsening at a critical current density of 96âmA/mm2. The climb and cross-slip of dislocation and the migration of grain boundary ultimately create variable lamellae spacing of TiAl alloy.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Materials Science & Technology - Volume 35, Issue 1, January 2019, Pages 23-28
Journal: Journal of Materials Science & Technology - Volume 35, Issue 1, January 2019, Pages 23-28
نویسندگان
Zhanxing Chen, Hongsheng Ding, Ruirun Chen, Shiqiu Liu, Jingjie Guo, Hengzhi Fu,