| 摘要 |
<p>A substantially crystalline cordierite ceramic article which is especially suited for electronic applications is formed by taking a shaped article which has been formed either from a magnesium exchanged zeolite powder or from a calcined product thereof, the zeolite selected from the group consistig of phillipsite, harmotome, gismondine, zeolite B, zeolite ZK-19 and zeolite W, and sintering the shaped article at a temperature of about 1,000 DEG C to 1,350 DEG C for about 1 to about 6 hours. The magnesium exchanged zeolite has a SiO2 /Al2O3 ratio of about 2.3 to about 2.8 and a sodium content less than 0.5 weight percent. The ceramic article that is formed has a substantially crystalline cordierite phase and has a density of at least 90% of its theoretical density. A preferred process involves calcining the magnesium exchanged zeolite powder at a temperature of about 600-800 DEG C to collapse the zeolite framework and give upon sintering a cordierite ceramic article which is substantially crack free. A preferred magnesium exchanged zeolite is magnesium exchanged zeolite B.</p> |
