摘要 |
A cordierite crystal-containing glaze for fine ceramics such as cordierite ceramics. The glaze has an oxide composition comprising, -SiO2 66-75 wt. % -Al2O3 13-22 -MgO 3-8-B2O3 2.5-7 -Na2O + K2O .4-2.0 - The above components should comprise at least 95%, and preferably 96-99%, of the total. The glaze can also include 0-2% ZnO and 0 PROPORTIONAL 2% ZrO2. Apart from colorants, the balance, if any, may comprise small amounts of other compatible compounds such as CaO, SrO, BaO, Cs2O and F2, up to a total of 3%; but the ratio of SiO2+Al2O3+MgO to the sum of such other compatible compounds should be at least about 28:1. Fe2O3 and TiO2, which are generally present as impurities in standard batch raw materials, are not harmful in amounts less than a total of 1.5%; in greater amounts, they begin to alter the color of the glaze. Li2O should not be present in any amount greater than about 0.5%. The glaze has good gloss and durability and is transparent in the absence of added pigmentation or refractory particles. |