Investigation of the phase composition and stability of the alpha-SiAlONs by the Rietveld method

Herrmann M., Kurama S., Mandal H.

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, vol.22, no.16, pp.2997-3005, 2002 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 16
  • Publication Date: 2002
  • Doi Number: 10.1016/s0955-2219(02)00037-7
  • Journal Name: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2997-3005
  • Keywords: sialons, Rietveld method, X-ray methods, Y-CONTAINING ALPHA-SI3N4, SOLID-SOLUTION FORMATION, SYSTEM SI,AL,Y/N,O, CERAMICS, ALPHA'-SIALON, SM
  • Anadolu University Affiliated: No

Abstract

Different compositions of Y- and Nd-alpha-SiAlONs were sintered at 1825 degreesC and analysed by the XRD method. The Rietveld technique was used for characterisation of the diffraction pattern and the x value of alpha-SiAlON, which has a composition of Rx+vSi12-(m + n)Alm + nOnN16 - n (R = Y, Nd). It was shown that the method yields reliable data for the content of the rare earth cations in the alpha-SiAlON phase, even in mixtures of alpha-SiAlONs with beta- or alpha-Si3N4, but cannot be used for the determination of the Al and/or O contents of the alpha-SiAlONs. On the basis of these data, the stability regions of Y- and Nd-alpha-SiAlONs were established. Furthermore, it was found that the solubility area of the alpha-SiAlONs depends on the size of the additives. It was also shown that the solubility area of the Y-alpha-SiAlON is extended to lower X values than those suggested in the literature. (C) 2002 Elsevier Science Ltd. All rights reserved.