초록 ▼

Cordierite compositions having increased porosity and improved thermal expansion characteristics are disclosed. The cordierite compositions comprise from about 0.025 to about 1.5 percent by weight germanium dioxide and exhibit reduced CTE. The cordierite compositions are made by heating a mixture of

Cordierite compositions having increased porosity and improved thermal expansion characteristics are disclosed. The cordierite compositions comprise from about 0.025 to about 1.5 percent by weight germanium dioxide and exhibit reduced CTE. The cordierite compositions are made by heating a mixture of kaolin, talc, alumina, kyanite and germanium dioxide to temperatures of between 1350°and 1475°C. The cordierite compositions are preferably made from a mixture which includes a calcined material, such as calcined talc, so that the mixture is more easily processed and the resulting cordierite compositions are more porous, and thus, more easily coated.

대표청구항 ▼

A ceramic composition made according to a process comprising the steps of: providing a substantially dry mixture comprising kaolin clay, talc, alumina, and kyanite; adding germanium dioxide to the substantially dry mixture in an amount from about 0.025 to about 1.5 percent by weight of the dry mixtu

A ceramic composition made according to a process comprising the steps of: providing a substantially dry mixture comprising kaolin clay, talc, alumina, and kyanite; adding germanium dioxide to the substantially dry mixture in an amount from about 0.025 to about 1.5 percent by weight of the dry mixture; adding liquid to said substantially dry mixture to form a wet mixture; forming the wet mixture into a shape; drying the formed shape; and heating said formed and dried shape to a temperature at which sintering occurs and cordierite is formed, said cordierite exhibiting a CTE which is essentially isotropic and is less than 1.24×10-6 in./in./°C.