Choi, HJ Lee, JG Kim, YW 2024-01-21T14:39:35Z 2024-01-21T14:39:35Z 2022-01-11 1999-12 0955-2219 https://pubs.kist.re.kr/handle/201004/141739 Four different beta-Si3N4 ceramics with silicon oxynitrides [Y-10(SiO4)(6)N-2, Yb4Si2N2O7, Er2Si3N4O3, and La-10(SiO4)(6)N-2, respectively] as secondary phases have been fabricated by hot-pressing the Si3N4-Re4Si2N2O7 (Re= Y, Yb, Er, and La) compositions at 1820 degrees C for 2h under a pressure of 25 MPa. The oxidation behavior of the hot-pressed ceramics was characterized and compared with that of the ceramics fabricated from Si3N4-Re2Si2O7 compositions. All Si3N4 ceramics investigated herein showed a parabolic weight gain with oxidation time at 1400 degrees C and the oxidation products of the ceramics were SiO2 and Re2Si2O7. The Si3N4-Re4Si2 N2O7 compositions showed inferior oxidation resistance to those from Si3N4-Re2Si2O7 compositions, owing to the incompatibility of the secondary phases of those ceramics with SiO2, the oxidation product of Si3N4. Si3N4 ceramics from a Si3N4-Er4Si2N2O7 composition showed the best oxidation resistance of 0.198 mg cm(-2) after oxidation at 1400 degrees C for 192h in air among the compositions investigated herein. (C) 1999 Elsevier Science Ltd. All rights reserved. English ELSEVIER SCI LTD SILICON-NITRIDE CERAMICS HIGH-TEMPERATURE STRENGTH MICROSTRUCTURE SYSTEM Oxidation behavior of hot-pressed Si3N4 with Re2O3 (Re = Y, Yb, Er, La) Article 10.1016/S0955-2219(99)00077-1 1 JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, v.19, no.16, pp.2757 - 2762 JOURNAL OF THE EUROPEAN CERAMIC SOCIETY 19 16 2757 2762 scie scopus 000083466200006 Materials Science, Ceramics Materials Science Article SILICON-NITRIDE CERAMICS HIGH-TEMPERATURE STRENGTH MICROSTRUCTURE SYSTEM hot pressing Si3N4 oxidation corrosion rare-earth oxides