کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
673108 1459488 2014 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A new model for diffusion-controlled precipitation reactions using the extended volume concept
ترجمه فارسی عنوان
یک مدل جدید برای واکنش های بارش تحت کنترل انتشار با استفاده از مفهوم حجم گسترده
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی


• New model for diffusion-controlled reactions using the extended volume concept.
• α = {exp(−2αext) − 1}/(2αext) + 1, where αext = (kt)n, α is fraction transformed, t is the time.
• Model fits well to extensive range of data, with reaction exponent n consistent with theory.

In this work a new model for diffusion-controlled precipitation reactions is derived, analysed and tested against a wide range of data. The model incorporates elements of the extended volume concept and combines this with a new treatment of soft impingement of diffusion fields. The model derivation involves an integration over iso-concentration regions in the parent phase in the extended volume, which leads to a single analytical equation describing the relation the fraction transformed, α, and the extended volume fraction, αext, as: α={exp(−2αext)−1}/(2αext)+1α={exp(−2αext)−1}/(2αext)+1. The model is compared to a range of new and old data on diffusion-controlled reactions including precipitation reactions and exsolution reactions, showing a very good performance, outperforming classical and recent models. The model allows new interpretation of existing data which, for the first time, show a consistent analysis, in which Avrami constants, n, equal values that are always consistent with transformation theory.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 596, 20 November 2014, Pages 109–119
نویسندگان
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