کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5437556 1398175 2017 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of oxidation on the mechanical properties and dielectric properties of porous Si3N4 ceramics
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
The effect of oxidation on the mechanical properties and dielectric properties of porous Si3N4 ceramics
چکیده انگلیسی

The effect of oxidation temperature and time on the microstructures, phase compositions, mechanical properties, and dielectric properties of porous Si3N4 ceramics was investigated in the temperature range from 900 °C to 1300 °C for 1 h, 5 h, and 24 h. The weight gain measured either at lower temperature (900 °C) for long time (24 h) or at higher temperature (1300 °C) for 1 h demonstrated that the porous Si3N4 ceramics were easily oxidized under the current test conditions. Results showed that the amount of open pores, flexural strength, compressive strength, and dielectric constant all decreased with the increase of oxidation temperature independent upon the oxidation time. The oxidation product SiO2 was low-temperature quartz in mild condition (low temperature, short time) and cristobalite in severe condition (high temperature, long time). The existence of cracks on the oxide scale was due to the phase transformation of SiO2 and thermal expansion coefficient mismatch between SiO2 and Si3N4.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 43, Issue 7, May 2017, Pages 5517-5523
نویسندگان
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