A ZrO.sub.2—Al.sub.2O.sub.3-based ceramic sintered compact containing tetragonal ZrO.sub.2 particles having a crystallite size of from 5 to 20 nm as a main component and having an α-Al.sub.2O.sub.3 crystallite size of not greater than 75 nm and a relative density of not less than 99% can be produced by preparing a Y.sub.2O.sub.3 partially stabilized ZrO.sub.2—Al.sub.2O.sub.3-based powder having a molar ratio (mol %) of zirconia (ZrO.sub.2) and yttria (Y.sub.2O.sub.3) of from 96.5:3.5 to 97.5:2.5 and a mass ratio (mass %) of ZrO.sub.2 containing Y.sub.2O.sub.3 and alumina (Al.sub.2O.sub.3) of from 85:15 to 75:25, molding this powder by cold isostatic pressing, and then performing sintering to a high density by microwave sintering for 45 to 90 min in an inert gas atmosphere at 1200 to 1400° C. When performing microwave sintering, a heating rate is preferably from 5 to 20° C./min up to 600° C. and from 50 to 150° C./min at 600° C. or higher.

A manufacturing method of a multilayer shell-core composite structural component comprises the following procedures: (1) respectively preparing feeding material for injection forming of a core layer, a buffer layer and a shell layer, wherein the powders of feeding material of the core layer and the shell layer are selected from one or more of metallic powder, ceramic powder or toughened ceramic powder, and are different from each other, and the powder of feeding material of the buffer layer is gradient composite material powder; (2) layer by layer producing the blank of multilayer shell-core composite structural component by powder injection molding; (3) degreasing the blank; and (4) sintering the blank to obtain the multilayer shell-core composite structural component. The multilayer shell-core composite structural component has the advantages of high surface hardness, abrasion resistance, uniform thickness of the shell layer, stable and persistent performance.

A sintered body including zirconia containing a stabilizer, wherein the sintered body has a monoclinic fraction of 0.5% or more and has a three-point bending strength of more than 1450 MPa as measured by a three-point bending test according to JIS R 1601. - - -

Disclosed is a ceramic sintered shaped body containing Y.sub.2O.sub.3-stabilized zirconia with a sintered density of at least 99% of the theoretical sintered density and having a mean grain size of <180 nm. The zirconia fraction of the sintered shaped body comprises tetragonal and cubic phases. Also disclosed is a process for the production of a ceramic sintered shaped body containing Y.sub.2O.sub.3-stabilized zirconia, which process comprises dispersion of a submicron powder and comminution of the dispersed submicron powder by means of grinding media having a diameter of less than or equal to 100 μm to a particle size d.sub.95 of <0.42 μm; shaping of the dispersion to form a body, and sintering of the body to form the sintered shaped body.

Disclosed herein are methods for producing an ultra-dense and ultra-smooth ceramic coating. A method includes feeding a solution comprising a metal precursor into a plasma sprayer. The plasma sprayer generates a stream toward an article, forming a ceramic coating on the article upon contact.

A ceramic composite material and a method for producing same. The ceramic composite material has a ceramic matrix comprising zirconium oxide and at least one secondary phase dispersed therein. The matrix is composed of zirconium oxide as at least 51 vol.-% of composite material, and the secondary phase is in a proportion of 1 to 49 vol.-% of composite material, wherein 90 to 99% of the zirconium oxide is present in the tetragonal phase based on the total zirconium oxide portion. The tetragonal phase of the zirconium oxide is stabilized by at least one member selected from the group consisting of chemical stabilization and mechanical stabilization. The ceramic composite is damage-tolerant.

Provided are metal oxide ceramic materials and intermediate materials thereof (e.g., nanozirconia gels, nanozirconia green bodies, pre-sintered ceramic bodies, zirconia dental ceramic materials, and dental articles). The nanozirconia gels are formable gels. Also provided are methods of making and using the metal oxide materials and intermediate materials. The nanozirconia gels can be made using, for example, osmotic processing. The nanozirconia gels can be used to make nanozirconia green bodies, pre-sintered ceramic bodies, zirconia dental ceramic materials, and dental article. The nanozirconia green bodies, pre-sintered ceramic bodies, zirconia dental ceramic materials, and dental articles have desirable properties (e.g., optical properties and mechanical properties).

In an embodiment, a method of manufacturing customized ceramic labial/lingual orthodontic brackets by additive manufacturing may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three dimensional computer-assisted design (3D CAD) model of the patient's teeth, and saving the 3D CAD model, designing a virtual 3D CAD bracket structure model for a single labial or lingual bracket structure based upon said 3D CAD model, importing data related to the 3D CAD bracket structure model into an additive manufacturing machine, and directly producing the bracket with the additive manufacturing machine by layer manufacturing from an inorganic material including at least one of a ceramic, a polymer-derived ceramic, and a polymer-derived metal.

A sintered body of the present invention is a sintered body including a first material and cubic boron nitride. The first material is partially-stabilized ZrO.sub.2 including 5 to 90 volume % of Al.sub.2O.sub.3 dispersed in crystal grain boundaries or crystal grains of partially-stabilized ZrO.sub.2.

The present invention relates to a kit of parts comprising a dental mill blank comprising a porous zirconia material and a colouring solution for colouring the porous zirconia material. The porous zirconia material comprises Zr oxide calculated as ZrO2: from 80 to 97 wt.-%, Al oxide calculated as Al2O3: from 0 to 0.15 wt.-%, Y oxide calculated as Y2O3: from 1 to 10 wt.-%, Bi oxide calculated as Bi2O3: from 0.01 to 0.2 wt.-%, the porous zirconia material not comprising Fe calculated as Fe2O3 in an amount of more than 0.01 wt.-%, wt.-% with respect to the weight of the porous zirconia material. The colouring solution comprises solvent(s), colouring agent(s) comprising metal ions selected from Tb, Er, Pr, Mn or combinations thereof, the solution not comprising Fe ions in an amount of more than 0.01 wt.-%, the solution not comprising Bi ions in an amount of more than 0.01 wt.-%, wt.-% with respect to the weight of the colouring solution. The invention also relates to a process of producing a dental restoration, the process comprising the steps: providing a dental mill blank comprising a porous zirconia material as described in any of the preceding claims, machining an article out of the porous zirconia material, the article having the shape of a dental restoration with an outer and inner surface, providing a colouring solution as described in any of the preceding claims, applying the colouring solution to at least portions of the surface of the article having the shape of a dental restoration.