| abstract |
A ceramic article which consists essentially, by weight on the oxide basis, of 10-25 % SiO2, 65-85 % Al2O3, and 2-12 % Li2O and comprises beta-eucryptite as a first phase having a negative component in thermal expansion and a melting point Tm1, and a second phase having a positive component in thermal expansion which is higher than the component in thermal expansion of the first phase and a melting point Tm2, wherein Tm2 > Tm1, wherein the first phase is at most 50 % by weight of the ceramic, and wherein the ceramic is characterized by microcracking. Tm2 is at least 1800 °C. The ceramic article exhibits a near zero coefficient of thermal expansion from room temperature to 800 °C, a high refractoriness, and a high resistance to thermal shock properties which make the inventive ceramic extremely desirable in high temperature applications, such as filters for diesel exhaust engines. |