Abstract: | The addition of NiO to a MgO Al2 Al2O3 SiO2 basic glass has an influence on the phase separation and crystallization mechanism. The differentiation of the components already detectable in the amorphous state continues in the crystallization process of the nickel-rich glasses. The formation of Ni Al-spinel in the bulk restricts the precipitation of high quartz crystals to the skin. The result is a high strength glass-ceramic with clearly distinguishable bulk and surface regions. |