Patent number: 6387318
Abstract: A dry pressing and slip casting process is provided for the manufacture of glass-ceramic components of the type used in sensors. Both process on starts with a powder composition of SiO2 (42-59 wt. %), Al2O3 (17-35 wt. %), MgO (2-25 wt. %) and also BaO (0-20 wt. %), TiO2 (0-12 wt. %), ZnO (0-10 wt. %), CaO (0-10 wt. %), B2O3 (0-5 wt %), P2O5 (0-5 wt. %), ZrO2 (0-5 wt. %), alkali oxides such as K2O, Na2O (0-3 wt. %) and other small amounts (0-1 wt. %) of additives such as Fe2O3, As2O3. Fe2O3, V2O5, As2O3. Some of the ingredients (e.g. Mg, Ba, Ca) can also be present in the form of fluoride, e.g., MgF2, BaF2, CaF2, to up to 10 wt. %. Additional ceramic additives up to 30 wt. %, which are as second phase (e.g., Al2O3, Y2O3 doped ZrO2, SiO2, mullite, zircon, carbides, nitrides, and a combination of the above), are not part of the glass composition, but are introduced to enhance both the mechanical strength and toughness and to further modify the coefficient of thermal expansion.
Type:
Grant
Filed:
August 10, 1999
Date of Patent:
May 14, 2002
Assignee:
AlliedSignal, Inc.
Inventors:
Liang A. Xue, Anthony J. Bernot, Grenville Hughes, Laura Lindberg