摘要:
Crack-free, dense and either amorphous or crystalline, nonoxide monolithic ceramic shaped articles are produced at relatively low temperatures, by shaping a powder (P) of an infusible, organometallic ceramic precursor polymer (Pi) into a green body having a relative density of at least 65%, and thence pyrolyzing such shaped green body.
摘要:
Zirconia ZrO.sub.2, ceria CeO.sub.2 or thoria ThO.sub.2 may be rendered ionically conductive; a typical composition is ZrO.sub.2 +12 mol % CaO.This is sintered in the solid state as a 40 nm powder using as a sintering additive 0.1 mol % MgO at 1450 C. for 4 hours; a density 98% of the theoretical is achieved.For other fluorite oxide compositions, MgO is also useful as a sintering additive but in different proportions.
摘要:
A class of ceramic mixed oxide, nonstoichiometric electrically neutral rare-earth-type catalyst containing rare-earth-type elements and elements of the first transition metal series and optionally the alkaline earth metals. The catalyst has the following formula: X.sub.n Y.sub.(1.sub.-n) ZO.sub.(3
摘要:
An oxygen sensing element has a body of chromium-rich zinc chromite and electrodes in contact with it for sensing the electrical resistance. At elevated temperatures, the resistance varies with oxygen concentration. A rare earth oxide dopant, preferably 15% mole percent Lanthanum 10 oxide, stabilizes and improves performance.
摘要:
A ceramic formed body having high temperature change resistance and stren and being composed of a ceramic matrix with dispersed particles of ZrO.sub.2, HfO.sub.2, or mixture thereof, is formed of a powdered ceramic material which is a precursor to the matrix material of the ceramic matrix, mixed with a compound which can form ZrO.sub.2, HfO.sub.2 or mixture thereof upon reaction with the ceramic material, and thereafter densely sintered below the reaction temperature. The sintered body is then heat treated above the reaction temperature to convert the precursor ceramic material into the matrix material and form the ceramic body with in situ formation of the dispersed particles.