کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5440932 | 1398241 | 2017 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Physical, thermal and ablative performance of CVI densified urethane-mimetic SiC preforms containing in situ grown Si3N4 whiskers
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A two-step process has been developed for silicon carbide (SiC) coated polyurethane mimetic SiC preform containing silicon nitride (Si3N4) whiskers. SiC/Si3N4 preforms were prepared by pyrolysis/siliconization treatment at 1600 °C, of powder compacts containing rigid polyurethane, novolac and Si, forming a porous body with in situ grown Si3N4 whiskers. The properties were controlled by varying Si/C mole ratios such as 1-2.5. After densification using a chemical vapour infiltration, the resulting SiC/Si3N4/SiC composites showed excellent oxidation resistance, thermal conductivity of 4.32-6.62 Wmâ1 Kâ1, ablation rate of 2.38 Ã 10â3 â 3.24 Ã 10â3 g cmâ2 s and a flexural strength 43.12-55.33 MPa for a final density of 1.39-1.62 gcmâ3. The presence of a Si3N4 phase reduced the thermal expansion mismatch resulting in relatively small cracks and well-bonded layers even after ablation testing. This innovative two-step processing can provide opportunities for expanded design for using SiC/Si3N4/SiC composites being lightweight, inexpensive, homogeneous and isotropic for various high temperature applications.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 37, Issue 2, February 2017, Pages 499-508
Journal: Journal of the European Ceramic Society - Volume 37, Issue 2, February 2017, Pages 499-508
نویسندگان
Shameel Farhan, Rumin Wang, Kezhi Li,