کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7973088 | 1514624 | 2018 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Rafting of γⲠprecipitates in a Co-9Al-9W superalloy during compressive creep
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The rafting of γⲠprecipitates was investigated in a single crystal of Co-9Al-9W(at%) superalloy after compression creep tests at 850â¯Â°C. Scanning electron micrographs show that the γⲠprecipitates raft perpendicular to the compressive stress axis, due to their positive lattice parameter misfit. The rafting of γⲠprecipitates occurred after the minimum strain rate was reached. The dislocation structure and stacking faults were investigated by transmission electron microscopy. Dislocations preferentially moved in the horizontal γ matrix channels where they can relieve the coherency stress at horizontal γ/γⲠinterfaces. After extended periods of creep, rafting of the γⲠprecipitates perpendicular to the external compressive stress axis occurred. The merging of γⲠprecipitates during rafting initiated at the precipitates corners, leaving pockets of matrix phase in the vertical γ channels between adjacent γⲠprecipitates. The necessary diffusion of alloying elements during the rafting process between the two orientations of matrix channels should be decelerated as diffusion is slower in the ordered L12 γⲠphase than in the disordered γ phase.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 719, 14 March 2018, Pages 43-48
Journal: Materials Science and Engineering: A - Volume 719, 14 March 2018, Pages 43-48
نویسندگان
Yuzhi Li, Florian Pyczak, Jonathan Paul, Michael Oehring, Uwe Lorenz, Zekun Yao, Yongquan Ning,