Hollow glass microsphere composites: preparation and properties

Abstract

Composites consisting of bonded hollow glass microspheres are promising for constructions in which materials are needed that combine a high Young's modulus with a low density. The elastic properties of ideally bonded hollow glass microsphere composites are predicted theoretically. Heat-treated castings of quartz glass microspheres approach the theoretical Young's modulus from below. The best result achieved was a Young's modulus of about 1 GPa with a strength of about 0.8 MPa at a density of about 180 kg m−3. This was obtained with a casting of quartz glass microspheres, bonded with mono-aluminium phosphate. Composites made by pressing of appropriate microsphere/ binder mixtures, followed by heating, had a density that was lower than for castings but had a Young's modulus far below the theoretical value.