Rapidly crystallized beta-spodumene glass-ceramic materials

摘要

Glasses in the Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 -MgO-ZnO- TiO.sub. 2 composition field, additionally containing PbO and/or one of B. sub.2 O. sub.3, Na.sub.2 O and P.sub.2 O.sub.5 are rapidly crystallized to beta- spodumene glass-ceramics at temperatures not exceeding 1000° C. to provide white, opaque glass-ceramic products exhibiting both low thermal expansion and good chemical durability.