Crystallization of lithium disilicate glass using microwave processing

The crystallization of lithium disilicate (LS ₂) 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 LS ₂glass. The LS ₂glass 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 LS ₂glass. Enhanced kinetics and slightly different crystallization mechanisms were observed in the VFM crystallization process as compared with the conventional one.