کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1581994 | 1514864 | 2008 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Low cycle fatigue mechanism of René 80 at high temperature-high strain
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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 low cycle fatigue René 80, a Ni-base superalloy, was studied at temperature of 871 °C, R = (Émin/Émax) = 0 and strain rate of about 2 Ã 10â3 sâ1. The dislocation structure and failure surface observations were evaluated through TEM and SEM. TEM studies showed that at ÎÉt = 0.8% during the first cycle the dislocations formed a hexagonal network in the γ-phase matrix. When the number of cycles increased, the density of dislocations increased as well. At N = Nf and ÎÉt = 0.8% the cutting of γⲠprecipitates took place. SEM studies at ÎÉt = 0.8% and N = Nf showed that fatigue crack initiation generally occurred at the surface, where it is depleted of the γⲠphase as a result of oxidation by the high-temperature exposure. In addition to depleted zones, the grain boundary oxidation and oxide spikes were also considered as further crack initiation sites.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 494, Issues 1â2, 25 October 2008, Pages 385-390
Journal: Materials Science and Engineering: A - Volume 494, Issues 1â2, 25 October 2008, Pages 385-390
نویسندگان
Kh. Rahmani, S. Nategh,