Surface modification of sodium aluminosilicate glasses using microwave energy

Microwave energy is becoming more important in the processing and fabrication of materials. Microwave heating is unique and may be regarded as an alternative processing means by which shorter processing times are often achieved. Heat generation upon material irradiation with microwaves is internal and volumetric. These thermal distributions make it possible to rapidly and uniformly heat treat large ceramic bodies. Several ceramic systems have been successfully sintered using microwave energy. The commonly observed high sintering rates and grain growth are thought to be due to enhanced diffusion brought about by the microwave field. However, experimental evidence to date has not provided the empirical data necessary to substantiate this claim.; This research is concerned with the issue of diffusion enhancements brought about by microwave energy (the so-called "microwave effect"). The major goal of this study was to provide the experimental evidence for microwave enhanced diffusion, if any.; Evidence of the existence of the microwave effect was demonstrated through an ion exchange (a diffusion controlled process) investigation performed on a specific glass system. In addition, the microwave benefits appear to depend on the structure of the material to be processed. A correlation was established between the structure of the glass compositions, their dielectric behavior and microwave enhanced diffusion.