Abstract: A process of synthesizing a yttrium aluminum garnet (YAG) powder. The process comprises introducing powders of yttria and silica to form a powder mixture, wherein alumina is not added to the powder mixture. Milling the powder mixture in the presence of an alumina grinding media and a solvent forms a powder slurry. Processing the powder slurry forms a green compact. Calcining the green compact at a temperature of from 1100° C. to 1650° C. for greater than 8 hours in air to 50% or less theoretical density forms a YAG compact of at least 92 wt % Y3Al5O12. Milling the YAG compact, without a grinding media, and drying produces the YAG powder. Processes further include introducing a dopant to the powder mixture to produce doped YAG powder.

Abstract: A process of synthesizing a yttrium aluminum garnet (YAG) powder. The process comprises introducing powders of yttria and silica to form a powder mixture, wherein alumina is not added to the powder mixture. Milling the powder mixture in the presence of an alumina grinding media and a solvent forms a powder slurry. Processing the powder slurry forms a green compact. Calcining the green compact at a temperature of from 1100° C. to 1650° C. for greater than 8 hours in air to 50% or less theoretical density forms a YAG compact of at least 92 wt % Y3Al5O12. Milling the YAG compact, without a grinding media, and drying produces the YAG powder. Processes further include introducing a dopant to the powder mixture to produce doped YAG powder.

Abstract: A freeze-forging method for producing sintered three-dimensional ceramic bodies, particularly magnesium aluminate spinel domes. The method comprises forming a ceramic mix of a ready-to-sinter ceramic powder and a nonaqueous liquefied sublimable vehicle having a solidification temperature from room temperature to below 200° C.; reducing the temperature of the ceramic mix to below the vehicle's solidification temperature to freeze the mix; crushing the frozen mix into powdered form; molding the frozen powder into net shape by cold forging in a mold to form a net-shaped green body preform of the desired three-dimensional shape; and densifying the green body into a sintered three-dimensional ceramic body.

Abstract: A freeze-forging method for producing sintered three-dimensional ceramic bodies, particularly magnesium aluminate spinel domes. The method comprises forming a ceramic mix of a ready-to-sinter ceramic powder and a nonaqueous liquefied sublimable vehicle having a solidification temperature from room temperature to below 200° C.; reducing the temperature of the ceramic mix to below the vehicle's solidification temperature to freeze the mix; crushing the frozen mix into powdered form; molding the frozen powder into net shape by cold forging in a mold to form a net-shaped green body preform of the desired three-dimensional shape; and densifying the green body into a sintered three-dimensional ceramic body.

Abstract: An in-situ method for nanomixing magnesium aluminate spinel nanoparticles with a uniformly distributed controlled concentration of nanoparticles of an inorganic sintering aid, such as LiF, to produce ready-to-sinter spinel powder. The spinel-sintering aid nanomixture is formed by induced precipitation of the sintering aid nanoparticles from a dispersion of the spinel nanoparticles in an aqueous solution of the sintering aid, followed by separation, drying and deagglomeration of the spinel-sintering aid nanomixed product.

Abstract: A freeze-forging method for producing sintered three-dimensional ceramic bodies, particularly magnesium aluminate spinel domes. The method comprises forming a ceramic mix of a ready-to-sinter ceramic powder and a nonaqueous liquefied sublimable vehicle having a solidification temperature from room temperature to below 200° C.; reducing the temperature of the ceramic mix to below the vehicle's solidification temperature to freeze the mix; crushing the frozen mix into powdered form; cold forging the frozen powder in a mold to form a solidified green body of the desired three-dimensional shape; and densifying the green body into a sintered three-dimensional ceramic body.

Abstract: An in-situ method for nanomixing magnesium aluminate spinel nanoparticles with a uniformly distributed controlled concentration of nanoparticles of an inorganic sintering aid, such as LiF, to produce ready-to-sinter spinel powder. The spinel-sintering aid nanomixture is formed by induced precipitation of the sintering aid nanoparticles from a dispersion of the spinel nanoparticles in an aqueous solution of the sintering aid, followed by separation, drying and deagglomeration of the spinel-sintering aid nanomixed product.

Abstract: A ceramic matrix nanocomposite having enhanced mechanical behavior is made up of a nanotube filler composed of at least one nanotube material, and a ceramic matrix composed of a nanocrystalline ceramic oxide. A method for producing ceramic articles having improved fracture toughness includes combining of a nanotube filler made up of a nanotube material and a ceramic matrix made up of a nanocrystalline ceramic oxide, forming an article therefrom, and sintering the article under elevated pressure at elevated temperature.