کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5356080 1503589 2016 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enhancing the oxidation resistance of graphite by applying an SiC coat with crack healing at an elevated temperature
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Enhancing the oxidation resistance of graphite by applying an SiC coat with crack healing at an elevated temperature
چکیده انگلیسی
The potential of reducing the oxidation of the supporting graphite components during normal and/or accident conditions in the Very High Temperature Reactor (VHTR) design has been studied. In this work efforts have been made to slow the oxidation process of the graphite with a thin SiC coating (∼ 10 μm). Upon heating at ≥ 1173 K in air, the spallations and cracks were formed in the dense columnar structured SiC coating layer grown on the graphite with a functionally gradient electron beam physical vapor deposition (EB-PVD. In accordance with the formations of these defects, the sample was vigorously oxidized, leaving only the SiC coating layer. Then, efforts were made to heal the surface defects using additional EB-PVD with ion beam bombardment and chemical vapor deposition (CVD). The EB-PVD did not effectively heal the cracks. But, the CVD was more appropriate for crack healing, likely due to its excellent crack line filling capability with a high density and high aspect ratio. It took ∼ 34 min for the 20% weight loss of the CVD crack healed sample in the oxidation test with annealing at 1173 K, while it took ∼ 8 min for the EB-PVD coated sample, which means it took ∼4 times longer at 1173 K for the same weight reduction in this experimental set-up.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 378, 15 August 2016, Pages 341-349
نویسندگان
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