Some Investigations of Alumino-Phosphate and Alumino Silicate Glasses
JSGT 1946 V30 T381-T396
The introduction of RO oxides at the expense of P2O5 in Al2O3–B2O3–P2O5 glasses greatly improves the ease of glass formation. By this means, aluminophosphate glasses with high deformation temperatures may be made. They are easy to melt and have considerably better electrical resistivity than glasses previously known. The introduction of alkali oxides into aluminophosphate glasses reduces their tendency to devitrification, and although their resistivities are reduced they remain excellent compared with the usual borosilicate and silicate glasses. Certain interchanges, for example the per cent. by weight interchange of SiO2 , MgO, CaO, BaO, have a different effect on the physical properties of aluminosilicate glasses as compared with their effect in silicate glasses. Aluminosilicate glasses with annealing temperatures as high as 800° have been developed i they may be melted at temperatures attainable, in present glass-works practice.
J. E. Stanworth