Study on Crystallization Process of Li<sub>2</sub>O–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> Glass-Ceramics Based on In Situ Analysis
oleh: Minghan Li, Chunrong Xiong, Yanping Ma, Hong Jiang
| Format: | Article |
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| Diterbitkan: | MDPI AG 2022-11-01 |
Deskripsi
In this paper, we used differential scanning calorimetry (DSC), high-temperature X-ray diffraction (HT-XRD), and confocal scanning laser microscopy (CSLM) to investigate the Li<sub>2</sub>O–Al<sub>2</sub>O<sub>3–</sub>SiO<sub>2</sub> glass crystallization process. At 943 K, lithium disilicate (Li<sub>2</sub>Si<sub>2</sub>O<sub>5</sub>) phase crystals began to precipitate in the Li<sub>2</sub>O–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> glass with a crystal size of 50–70 nm. At the temperature of 1009 K, petalite (LiAlSi<sub>4</sub>O<sub>10</sub>) crystals began to precipitate in the vitreous phase, forming composite spherical crystals of LiAlSi<sub>4</sub>O<sub>10</sub> and Li<sub>2</sub>Si<sub>2</sub>O<sub>5</sub> with size in the range of 90–130 nm. Furthermore, the Kissinger method and KAS method of the JMAK model were used to calculate the crystallization activation energy and the Avrami index “<i>n</i>”. It was found that the precipitation mechanism of the two kinds of crystals is whole crystallization; accordingly, the selection of crystallization heat treatment system was guided to determine the nucleation and crystallization temperature.