Crystallization of Lithium Disilicate Glass Using Microwave Processing

The crystallization of lithium disilicate (LS2) glass using a variable frequency microwave (VFM) processing technique was investigated. Lithium disilicate glass samples were prepared from commercial frit using a conventional glass melting and casting technique. A two-stage heat-treatment regime was used to crystallize the glass samples. The nucleation and crystallization temperatures were determined by the thermal analysis of the prepared LS2 glass. The LS2 glass samples were nucleated by conventional heating, followed by the crystallization step using two different techniques: conventional and microwave crystallization. Characterization of the prepared glass-ceramic samples by both techniques was conducted using X-ray diffraction, Fourier transform infrared reflectance spectroscopy, Raman spectroscopy, and scanning electron microscopy. Variable frequency microwave processing was successfully used to crystallize LS2 glass. Enhanced kinetics and slightly different crystallization mechanisms were observed in the VFM crystallization process as compared with the conventional one.