The microwave sintering of glass-ceramics, non-thermal microwave effect, and crystal growth mechanism remain important challenges in materials science. In this study, we focus on developing approaches to affect crystal growth in the glass network of glass-ceramics by microwave heating, rather than performing a single study on the crystal structure and type. Raman spectroscopy is used to detect the structure of the glass network. We demonstrated that the non-thermal microwave effect promoted the diffusion of metal ions, which promoted the aggregation and precipitation of metal ions in the glass network to form crystals. The samples produced by microwave heating contain more non-bridging oxygen bonds than conventional sintered samples; therefore, the non-thermal microwave effect has a depolymerization effect on the glass network of the sample. Under the influence of microwave field, many metal ions precipitate, which precipitates many crystal nuclei. In addition, many active metal ions are captured during the crystal nucleus growth, which shortens the sintering process of glass-ceramics.
Keywords: Raman spectroscopy; glass-ceramics; microwave sintering; non-thermal microwave effect.