Thermal Properties of Nitrogen-Rich Ca-α-Sialons
2009 (English)In: Journal of the European Ceramic Society, ISSN 0955-2219, Vol. 29, no 16, 3409-3417 p.Article in journal (Refereed) Published
Nitrogen-rich Ca-α-Sialon (CaxSi12−2xAl2xN16 with x = 0.2, 0.4, and 0.8, 1.2 and 1.6) ceramics were prepared from the mixtures of Si3N4, AlN and CaH2 powders in a hot press at 1800 °C using a pressure of 35 MPa and a holding time of 4 h, and then were investigated with respect to reaction mechanism, phase stability and oxidation resistance. In addition the sample with x = 1.6 was prepared in the temperature range 600–1800 °C using a pressure of 35 MPa and a holding time of 2 h. The α-Sialon phase was first observed at 1400 °C but the α-Si3N4 and AlN phases were still present at 1700 °C. Phase pure Ca-α-Sialon ceramics could not be obtained until the sintering temperature reached 1800 °C. The phase pure nitrogen-rich Ca-α-Sialon exhibited no phase transformation in the temperature range 1400–1600 °C. In general, mixed α/β-Sialon showed better oxidation resistance than pure α-Sialon in the low temperature range (1250–1325 °C), while α-Sialons with compositions located at α/β-Sialon border-line showed significant weight gains over the entire temperature range tested (1250–1400 °C). The phases formed upon oxidation were characterized by X-ray, SEM and TEM studies.
Place, publisher, year, edition, pages
2009. Vol. 29, no 16, 3409-3417 p.
IdentifiersURN: urn:nbn:se:su:diva-25769DOI: 2122/10.1016/j.jeurceramsoc.2009.07.015ISI: 000270694400014OAI: oai:DiVA.org:su-25769DiVA: diva2:200493
Part of urn:nbn:se:su:diva-85682009-02-262009-02-172010-01-26Bibliographically approved