| abstract |
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 DEG and 1475 DEG 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. |