Lanthanum-Containing Cordierite Body And Method Of Manufacture
AssigneeCorning Incorporated
InventorGregory Albert Merkel
Life of this patent
Estimating the term…
Abstract
Lanthanum containing cordierite bodies are provided that exhibit high strength, little or no microcracking, and a high thermal shock resistance. Improved maintenance of low microcracking and high strength is obtained even after exposure to high temperatures.
Claims32
A ceramic body comprising a predominant cordierite ceramic phase and at least about 0.1 wt % lanthanum oxide contained within the microstructure of the ceramic, the article exhibiting:
- a four-point beam bending modulus of rupture at 25° C. (room-temperature), MOR;
- a room-temperature elastic modulus E as measured by a sonic resonance technique at 25° C.;
- and a coefficient of thermal expansion CTE200-1000 from 200° C.-1000° C. in units of ° C.−1;
- wherein the ceramic body is characterized by a dimensionless strain tolerance, defined by a ratio MOR/E, and a thermal shock resistance, defined by TSL200=200° C.+(MOR/E)/CTE200-1000, wherein the ceramic body exhibits MOR/E>0.12×10−2 and TSL200≧900° C. after being at room temperature and then being subjected to a heat treatment including being exposed to an environment with a temperature in a range of 800° C. to 1100° C. for at least 25 hours.
A ceramic body comprising a predominant cordierite ceramic phase and at least about 0.1 wt % lanthanum oxide contained within the microstructure of the ceramic, the article exhibiting:
- a coefficient of thermal expansion CTE25-800 greater than 14.0×10−7° C.−1 from 25° C.-800° C.;
- an elastic modulus ratio E800/E25≦1.00;
- a four-point beam bending modulus of rupture at 25° C. (room-temperature), MOR;
- and a room-temperature elastic modulus E as measured by a sonic resonance technique at 25° C.;
- wherein the ratio MOR/E is a dimensionless strain tolerance, and MOR/E≧0.10%.
A ceramic body comprising a predominant cordierite ceramic phase and at least about 0.1 wt % lanthanum oxide contained within the microstructure of the ceramic, the article exhibiting:
- a four-point beam bending modulus of rupture at 25° C. (room-temperature), MOR;
- a room-temperature elastic modulus E as measured by a sonic resonance technique at 25° C.;
- and a coefficient of thermal expansion CTE200-1000 from 200° C.-1000° C. in units of ° C.−1;
- wherein the ceramic body is characterized by a dimensionless strain tolerance, defined by a ratio MOR/E, and a thermal shock resistance, defined by TSL200=200° C.+(MOR/E)/CTE200-1000, wherein the ceramic body exhibits MOR/E>0.10×10−2 and TSL200≧800° C. after being at room temperature and then being subjected to a heat treatment including being exposed to an environment with a temperature in a range of 800° C. to 1100° C. for at least 25 hours, and wherein the ceramic body contains Fe2O3 and CaO in a total combined amount of less than 1.40 wt %.
Dependencies are inferred from the claim text.