کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7887057 | 1509789 | 2018 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
In-situ formation of BN layers by nitriding boron powders in BN/Si3N4-based composite ceramics
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
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چکیده انگلیسی
Boron nitride/silicon nitride (BN/Si3N4) composite ceramics were fabricated via the in-situ nitridation of boron (B) and silicon (Si) powders in forming gas (95%N2/5%H2) at 1390â¯Â°C. The effect of the B content on the phase composition, microstructure, density/porosity, machinability as well as mechanical properties of nitridized BN/Si3N4 composite ceramics was investigated. The addition of B slightly increased the nitridation degree of the Si and B powders mixture, and improved the ratio of the β-Si3N4 phase significantly at low B contents. B powders may have acted as a nucleating agent to promote the formation of β-Si3N4 crystals. A core-shell Si3N4/BN structure was revealed by the TEM technique, and the number of BN layers increased with the increase of the B content. The in-situ BN formed by the nitridation of B played a similar role with the BN directly added in enhancing the machinability of the BN/Si3N4 composite ceramics. The method of the in-situ nitridation of B is also effective to prepare SiC fiber-reforced BN/Si3N4 ceramic matrix composites.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 44, Issue 9, 15 June 2018, Pages 10322-10327
Journal: Ceramics International - Volume 44, Issue 9, 15 June 2018, Pages 10322-10327
نویسندگان
Xueyuan Tang, Yongwei Li, Xuan Cheng, Ying Zhang,