کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7882344 1509607 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Repetitive grain growth behavior with increasing temperature and grain boundary roughening in a model nickel system
ترجمه فارسی عنوان
رفتار رشد تکراری با افزایش دما و مرطوب شدن دانه در یک سیستم نیکل مدل
کلمات کلیدی
رفتار رشد دانه، رشد غیرطبیعی دانه، نیکل، مدل کنترل مخلوط، تکامل میکروارگانیسم،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
چکیده انگلیسی
In conjunction with a previous investigation [Jung SH, Yoon DY, Kang SJL. Acta Mater 2013;61:5685], we have investigated the correlation between grain boundary structure and grain growth behavior in a model Ni system. Ultrafine Ni powder compacts of 180 nm size were sintered in a wide range of temperatures from 500 to 1150 °C and for various times in wet H2. Between 500 and 600 °C, abnormal grain growth (AGG) readily occurred, with the formation of cube-shaped grains. Between 650 and 900 °C, grain growth behavior was stagnant up to 6000 min due to impingement of rapidly grown abnormal cube-shaped grains during heating. At 950 °C, some of the impinged abnormal grains suddenly grew after 20 min, showing secondary AGG behavior. As the sintering temperature was increased further, the grain growth behavior became quite normal. These changes in grain growth behavior with increasing temperature were accompanied by the structural transition of grain boundaries from fully faceted to partially faceted and defaceted. The observed grain growth behavior with respect to the grain boundary morphology is explained in terms of a coupling effect of the maximum driving force for grain growth and the critical driving force for appreciable migration of faceted boundaries. The present experimental results appear to support the validity of the previously suggested mixed control model of grain growth and the principle of microstructural evolution in polycrystals.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 69, May 2014, Pages 283-291
نویسندگان
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