| abstract |
PCT No. PCT/US97/20434 Sec. 371 Date Apr. 9, 1999 Sec. 102(e) Date Apr. 9, 1999 PCT Filed Nov. 7, 1997 PCT Pub. No. WO98/22405 PCT Pub. Date May 28, 1998Nanocrystalline glass-ceramic materials based on beta -quartz solid solution Mg-rich phases formed in the system SiO2-Al2O3-MgO-Li2O-TiO2(ZnO, BaO, ZrO2, P2O5). Articles made from the glass-ceramic materials exhibit a crystal phase assemblage of a fine-grained, microstructure which is predominantly beta -quartz, and at least one additional phase selected from enstatite and spinel, and having a composition which consists essentially of, in weight percent on the oxide basis, 40-65% SiO2, 10-14% Al2O3, 5-25% MgO, 0.5-4% Li2O, 5-15% TiO2, and up to 5% ZrO2, such that the sum of (TiO2+ZrO2) is at least 9% The glass-ceramide article is particularly useful for memory disk applications. |