Preparation of homogeneous barium borosilicate glass using microwave energy

Barium borosilicate glass having composition in wt.% (46.5) SiO2, (26.5) B2O3, (16.5) Na2O (10.5) BaO was melted at 1473 K in a microwave furnace and also in a conventional resistance heating furnace. A comparative study of the properties of both the glasses was conducted by adopting standard methods of characterisation. Glass transition temperature was recorded as 825 K and 829 K for glass samples prepared in microwave and conventional heating respectively. Low evaporation of volatile component was observed in microwave prepared glass which leads to less density of glass in comparison with glass prepared in conventional method. ‘Self stirring’ effect in microwave prepared glass sample was observed in annealed glass obtained without pouring it into preheated mold. Identical structure and optical transmission were found in both the glasses. OH content was estimated low in glass melted in microwave heating over conventional heating. Microwave heating can be a potential alternative method of preparing glass with substantial reduction of energy and processing time.