A method for producing a transparent alumina sintered body according to the present invention includes (a) a step of preparing an alumina raw material powder containing a plate-like alumina powder having an aspect ratio of 3 or more and a fine alumina powder having an average particle diameter smaller than that of the plate-like alumina powder so that, when a mixing ratio of the plate-like alumina powder to the fine alumina powder in terms of mass ratio is assumed to be T:(100T), T is 0.001 or more and less than 1, and so that a mass ratio R1 of F relative to Al in the alumina raw material powder is less than 15 ppm; (b) a step of forming a raw material for forming containing the alumina raw material powder into a compact; and (c) a step of sintering the compact so as to obtain a transparent alumina sintered body.

A method for producing a transparent alumina sintered body according to the present invention includes (a) a step of preparing an alumina raw material powder containing a plate-like alumina powder having an aspect ratio of 3 or more and a fine alumina powder having an average particle diameter smaller than that of the plate-like alumina powder so that, when a mixing ratio of the plate-like alumina powder to the fine alumina powder in terms of mass ratio is assumed to be T:(100T), T is 0.001 or more and less than 1, and so that a mass ratio R1 of F relative to Al in the alumina raw material powder is less than 15 ppm; (b) a step of forming a raw material for forming containing the alumina raw material powder into a compact; and (c) a step of sintering the compact so as to obtain a transparent alumina sintered body.

An optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al.sub.2O.sub.3 crystal grains and crystal grains of a component represented by formula A.sub.3B.sub.5O.sub.12:Ce, wherein A is at least one element selected from Sc, Y and lanthanoids (except for Ce), and B is at least one element selected from Al and Ga. Further, the following relations are satisfied: 0%X25%, 9%Y45%, and 48%Z90%, wherein X represents a proportion corresponding to the ratio a/N, Y represents a proportion corresponding to the ratio b/N, and Z represents a proportion corresponding to the ratio c/N and a, b, c and N are as defined herein. Also disclosed is a light-emitting device including the optical wavelength conversion member.

An optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al.sub.2O.sub.3 crystal grains and crystal grains of a component represented by formula A.sub.3B.sub.5O.sub.12:Ce, wherein A is at least one element selected from Sc, Y and lanthanoids (except for Ce), and B is at least one element selected from Al and Ga. Further, the following relations are satisfied: 0%X25%, 9%Y45%, and 48%Z90%, wherein X represents a proportion corresponding to the ratio a/N, Y represents a proportion corresponding to the ratio b/N, and Z represents a proportion corresponding to the ratio c/N and a, b, c and N are as defined herein. Also disclosed is a light-emitting device including the optical wavelength conversion member.

A method of manufacturing ceramic tape includes a step of directing a tape of partially-sintered ceramic into a furnace. The tape is partially-sintered such that grains of the ceramic are fused to one another yet the tape still includes at least 10% porosity by volume, where the porosity refers to volume of the tape unoccupied by the ceramic. The method further includes steps of conveying the tape through the furnace and further sintering the tape as the tape is conveyed through the furnace. The porosity of the tape decreases during the further sintering step.

A method of manufacturing ceramic tape includes a step of directing a tape of partially-sintered ceramic into a furnace. The tape is partially-sintered such that grains of the ceramic are fused to one another yet the tape still includes at least 10% porosity by volume, where the porosity refers to volume of the tape unoccupied by the ceramic. The method further includes steps of conveying the tape through the furnace and further sintering the tape as the tape is conveyed through the furnace. The porosity of the tape decreases during the further sintering step.

A ceramic and polymer composite including: a first continuous phase comprising a sintered porous ceramic having a solid volume of from 50 to 85 vol % and a porosity or a porous void space of from 50 to 15 vol %, based on the total volume of the composite; and a second continuous polymer phase situated in the porous void space of the sintered porous ceramic. Also disclosed is a composite article, a method of making the composite, and a method of using the composite.

A ceramic and polymer composite including: a first continuous phase comprising a sintered porous ceramic having a solid volume of from 50 to 85 vol % and a porosity or a porous void space of from 50 to 15 vol %, based on the total volume of the composite; and a second continuous polymer phase situated in the porous void space of the sintered porous ceramic. Also disclosed is a composite article, a method of making the composite, and a method of using the composite.

The formed ceramic abrasive particle includes a plurality of ceramic oxides. The particle further includes a first plurality of oxides, a second plurality of oxides, or a mixture thereof. The first plurality of oxides includes an oxide of yttrium, praseodymium, samarium, ytterbium, neodymium, lanthanum, gadolinium, dysprosium, erbium, or a combination thereof. The second plurality of oxides includes an oxide of iron, magnesium, zinc, silicon, cobalt, nickel, zirconium, hafnium, chromium, cerium, titanium, or a combination thereof. The formed ceramic abrasive particle further includes a plurality of edges, each edge having a length independently ranging from about 0.1 m to about 5000 m. The formed ceramic abrasive particle further includes a tip defined by a junction of at least two of the edges, the tip can have a radius of curvature ranging from about 0.5 m to about 80 m.

High strength transparent corundum ceramics using corundum powder and methods of manufacture are disclosed. The method of forming transparent corundum ceramics includes milling corundum powder in aqueous slurry with beads. The method further includes processing the slurry by a liquid shaping process to form a gelled body. The method further includes sintering the gelled body in air and pressing the gelled body by hot isostatic pressing to form a ceramic body.