کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5440364 1398227 2017 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Role of thermodynamic miscibility gaps in phase selection in sol-gel synthesis of yttrium silicates
ترجمه فارسی عنوان
نقش شکاف ترمودینامیکی اختلاط در انتخاب فاز در سنتز سل-ژل سیلیکات یتیم
کلمات کلیدی
کالفاد، مراحل متاستاز جداسازی فاز، تجزیه اسپینودال، سیلیکات یتریم،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
چکیده انگلیسی
Yttrium monosilicate and disilicate are important materials for environmental barrier coatings. The two silicates were synthesized by sol-gel route and their phase selection upon calcination and thermal exposure was studied. First products of crystallization were the monosilicate and yttria. Amorphous silica precipitated out at 1300 °C as apatite phase. During prolonged high temperature treatment, up to 100 h at 1400 °C, the apatite disappeared and the disilicate appeared, only to disappear itself as the system approached equilibrium. Thermodynamic calculations performed using Thermo-Calc software show the presence of a metastable miscibility gaps in the amorphous (liquid) phase field. As a consequence, phase separation in the amorphous phase prior to crystallization is responsible for the formation of yttria-rich and silica-rich phases during crystallization. Multiple phase formation during both, yttrium monosilicate and disilicate synthesis is consistent with the presence of the amorphous phase miscibility gaps around the silicate compositions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 37, Issue 15, December 2017, Pages 5001-5007
نویسندگان
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