Properties of the oxide compound spherulites, obtained from the melt in a solar furnace

The properties of the spherulites based on aluminum oxide, mullite, and zirconium dioxide that are obtained by melting and subsequent quenching in a 1000 kW solar furnace are studied. These spherulites are hollow. The thickness of the wall of the sphere is determined by the quenching rate. The microstructure of the spherulites that are based on aluminum oxide consists of crystallites of cubic form, the microstructure of the spherulites that are based on zirconium dioxide consists of micrograins of rounded form. The hardness and the elastic properties exceed the known values for the electrically melted materials that are based on corundum and zirconium dioxide.