کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8148362 1524331 2018 31 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Transition from hypereutectic to hypoeutectic for rapid solidification in an undercooled Co-B alloy
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Transition from hypereutectic to hypoeutectic for rapid solidification in an undercooled Co-B alloy
چکیده انگلیسی
Phase selection, a common and important phenomenon in rapid solidification, determines the solidification sequence and the mechanical/physical properties. In this work, a Co-20 at%B hypereutectic alloy was undercooled by the melt fluxing technique and the microstructure was characterized by the back-scattering diffraction technique. A transition from hypereutectic to hypoeutectic was found at a critical undercooling of ΔT = 119 K. When ΔT < 119 K, a primary directional dendritic β-Co3B phase surrounded by the regular α-Co + β-Co3B lamellar eutectics was found. When ΔT > 119 K, the above hypereutectic microstructure changes into hypoeutectic structure with the α-Co phase as the primary phase. According to dendrite growth model, the transition from hypereutectic to hypoeutectic can be ascribed to the higher growth velocity of the α-Co phase than the β-Co3B phase, i.e., the growth-controlled mechanism. The current work shows also that there is a coupled zone skewed to the β-Co3B phase in the Co-B alloys system.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Crystal Growth - Volume 499, 1 October 2018, Pages 98-105
نویسندگان
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