| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | H. 한-일 재료공학 워크샵 |
| 제목 | Crystallization of Glass with Ln2Si2O7-mullite Eutectic Composition Prepared by Rapid Quenching and Sol-gel Method |
| 초록 | In this paper, the crystallization mechanism of the glass with Y2Si2O7-mullite eutectic composition prepared by rapid quenching form the liquid phase and sol-gel method was examined. The microstructure formation from the different glass was discussed. For the glass prepared by rapid quenching, a dendrite Y2Si2O7 crystalline grows from the surface of the glass bulk at 1030oC (Fig.1). A competitive growth of Y2Si2O7 phase and mullite phase occurs at 1157oC. The activation energy for the competitive growth can be estimated to 329 kJ/mol. The activation energy for the crystallization of hypoeutectic and hypereutectic composition increases with increasing the amount of the primary phase [1]. A crystallization of Y2Si2O7 and the mullite phase due to phase separation occurred at 1174oC, and a well-developed Y2Si2O7 facet crystal was formed. This sample was melted down and solidified via heat treatment at 1250oC and 1300oC, temperatures below the melting point of a Y2Si2O7-mullite eutectic. As a result of this solidification, a directional eutectic microstructure was formed. An eutectic structure can be obtained by an heat treatment at 1250oC as shown in Fig.2 [2]. The crystallization of the glass prepared by sol-gel method is similar to that the glass prepared by rapid quenching. In the presentation, the crystallization mechanism of the glass with Yb2Si2O7-mullite is also discussed. REFERENCES [1] S. Ueno, Y. Suzuki, Y. Furukawa, T. Tada, N. Kanno and B-K Jang, “Crystallization of Glass with Y2Si2O7-Mullite Eutectic Composition”, J. Ceram. Soc. Jpn, vol. 124, pp. 796-99, 2016. [2] S. Ueno, T. Tada, Y. Suzuki, J. Nozawa, B-K. Jang, T. Sekino, “Crystallization and Microstructure Formation of Glass with Y2Si2O7-Mullite Eutectic Composition”, Ceram. Int., vol. 42, pp. 13601-04, 2016. |
| 저자 | Shunkichi UENO1, Yohei SUZUKI1, Naoto KANNO1, Takumi OHSHIMA1, Byung-Koog JANG2 |
| 소속 | 1Nihon Univ., 2National Institute for Materials Science |
| 키워드 | crystallization of glass; dendrite growth; phase separation; eutectic |
