2015-Sustainable Industrial Processing Summit
SIPS 2015 Volume 8: Composite & Ceramic, Quasi-crystals and Nanomaterials
| Editors: | Kongoli F, Pech-Canul M, Kalemtas A, Werheit H |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2015 |
| Pages: | 300 pages |
| ISBN: | 978-1-987820-31-7 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Oxidation Study of Sodium Borate Bonded SiC-Si3N4 Composites
Gulsum Topates1; Ayse Kalemtas2;1CANAKKALE ONSEKIZ MART UNIVERSITY, Canakkale, Turkey; 2BURSA TECHNICAL UNIVERSITY, Bursa, Turkey;
Type of Paper: Regular
Id Paper: 397
Topic: 18
Abstract:
Non-oxide ceramics provide better mechanical and thermal properties compared to their oxide counterparts. On the other side, special sintering conditions such as high temperature, protective atmosphere and sometimes application of an external pressure are necessary to obtain flaw-free non-oxide ceramics and this limits processing and further application of these ceramics. To ease these limitations, studies have been carried out to lower sintering temperature under atmospheric conditions.
In this study, sodium borate was used to lower the sintering temperature. SiC-Si3N4 mixtures were prepared with various amounts of sodium borate and SiC-Si3N4 for TG-DSC analysis. TG-DSC analyses were performed up to 1200oC by using two different heating rate, 5 and 20oC/min. Also, TG-DSC analyses were applied for pure Si3N4, SiC and Si3N4-SiC mixtures for reliable comparison. While oxidation for pure mixtures were started above 1000oC, addition of sodium borate decreases the oxidation temperature to 800oC. The weight gain changed approximately 4 wt% for pure mixtures and this value increased to 10 wt% for mixtures that contain sodium borate. XRD studies revealed that mixtures with sodium borate had cristobalite as a major phase.