An investigation on the thermal and microstructural properties of low-cost pressureless sintered silicon nitride (Si3N4) ceramics incorporated with Y2O3-SiO2-MgO

UYAN P., Cengiz Ö., Turan S.

Journal of the Australian Ceramic Society, cilt.58, sa.5, ss.1433-1443, 2022 (Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 58 Sayı: 5
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1007/s41779-022-00779-2
  • Dergi Adı: Journal of the Australian Ceramic Society
  • Derginin Tarandığı İndeksler: Scopus, Aerospace Database, Communication Abstracts, Metadex, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.1433-1443
  • Anahtar Kelimeler: Microstructure-final, Pressureless sintering, Silicon nitride, Ternary sintering additives, Thermal properties
  • Bilecik Şeyh Edebali Üniversitesi Adresli: Evet

Özet

© 2022, The Author(s) under exclusive licence to Australian Ceramic Society.Y2O3-SiO2-MgO-incorporated silicon nitride (Si3N4) ceramics were investigated systemically to obtain cost-effective production and the effect of sintering temperature on the microstructure and thermal properties was studied. An α-Si3N4 starting powder was used for preparing the samples and sintered under a pressure of one bar nitrogen gas pressure at 1650, 1700, 1750, 1800, and 1850 ℃ for 2 h. The crystallisation behaviour of the ceramics was promoted by sintering temperatures as evidenced by the XRD results. A different secondary phase, melilite (Y2Si3O3N4) formation, was detected using SEM micrographs of the final microstructures of the samples sintered at higher temperatures above 1700 ℃ which had a positive effect on thermal properties. The values of thermal conductivity increased by about 75.5% with increasing sintering temperature. The highest thermal conductivity (53.58 W/(mK)) was achieved with the highest sintering temperature of 1850 ℃. The results revealed that ternary sintering additives, such as Y2O3-SiO2-MgO, had a potential for low-cost production of Si3N4 ceramics with enhanced thermal properties.