Provided is at least any of a layered body, which has a change in texture derived from zirconia, particularly a change in translucency and is suitable as a dental prosthetic member, a precursor thereof, or a method for producing these. There is provided a layered body having a structure in which two or more layers containing zirconia containing a stabilizer are layered, the layered body including at least: a first layer containing zirconia having a stabilizer content of higher than or equal to 4 mol %; and a second layer containing zirconia having a stabilizer content different from that of the zirconia contained in the first layer.

There is provided at least any of a layered body which has a change in color tone and in which it is unnecessary to select a colorant and the content of the colorant in consideration of a difference in the sintering behavior between layers, a precursor thereof, or a method for producing these. Provided is a layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body including at least: a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 3.3 mol %; and a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer.

A copper/ceramic bonded body is provided, including: a copper member made of copper or a copper alloy; and a ceramic member, the copper member and the ceramic member being bonded to each other, in which a total concentration of Al, Si, Zn, and Mn is 3 atom % or less when concentration measurement is performed by an energy dispersive X-ray analysis method at a position 1000 nm away from a bonded interface between the copper member and the ceramic member to a copper member side, assuming that a total value of Cu, Mg, Ti, Zr, Nb, Hf, Al, Si, Zn, and Mn is 100 atom %.

Disclosed herein is a dual density disc comprising a dense outer tube comprising alumina having a purity of greater than 99%; and a porous core comprising alumina of a lower density than a density of the dense outer tube; wherein the porous core has an alumina purity of greater than 99%. Disclosed herein too is method comprising disposing in a dense outer tube a slurry comprising alumina powder and a pore former; heating the dense outer tube with the slurry disposed therein to a temperature of 300 to 600° C. to activate the pore former; creating a porous core in the dense outer tube; and sintering the dense outer tube with the porous core at a temperature of 800 to 2000° C. in one or more stages.

A layered body, which has a change in texture derived from zirconia, particularly a change in translucency and is suitable as a dental prosthetic member, a precursor thereof, or a method for producing these. The layered body has a structure in which two or more layers containing zirconia containing a stabilizer are layered, the layered body including at least: a first layer containing zirconia having a stabilizer content of higher than or equal to 4 mol %; and a second layer containing zirconia having a stabilizer content different from that of the zirconia contained in the first layer. At least one layer contains one or more elements capable of coloring zirconia.

There are provide a metal/ceramic bonding substrate wherein the bonding strength of an aluminum plate bonded directly to a ceramic substrate is higher than that of conventional metal/ceramic bonding substrates, and a method for producing the same. The metal/ceramic bonding substrate is produced by a method including the steps of: arranging a ceramic substrate 10 in a mold 20; putting the mold 20 in a furnace; lowering an oxygen concentration to 25 ppm or less and a dew point to −45° C. or lower in the furnace; injecting a molten metal of aluminum into the mold 20 so as to allow the molten metal to contact the surface of the ceramic substrate 10; and cooling and solidifying the molten metal to form a metal plate 14 for circuit pattern of aluminum on one side of the ceramic substrate 10 to bond one side of the metal plate 14 for circuit pattern directly to the ceramic substrate 10, while forming a metal base plate 12 of aluminum on the other side of the ceramic substrate 10 to bond the metal base plate 12 directly to the ceramic substrate 10.

The invention relates to a process for metallizing ferrite ceramics, which comprises the following steps: arrangement of a contact element composed of copper or a copper alloy on a surface of the ferrite ceramic, melting of the contact element at least in the region in which the contact element contacts the surface of the ferrite ceramic, and cooling of the contact element and the ferrite ceramic to below the melting point of copper or the copper alloy.

A method for preparing a ceramic copper clad laminate is provided, including following steps: providing a copper material; forming a copper oxide layer on a surface of the copper material; thermally treating the copper material on which the copper oxide layer is formed, to diffuse oxygen atoms in the copper material; removing the copper oxide layer on the thermally treated copper material; and soldering the copper-oxide-layer-removed copper material to a ceramic substrate to obtain a ceramic copper clad laminate.

This pure copper plate includes Cu having a purity of 99.96 mass % or higher, with a remainder of unavoidable impurities, wherein an amount of P is 2 mass ppm or less, and a total amount of Pb, Se, and Te is 10 mass ppm or less. The amount of S may be in a range of 2 mass ppm or more and 20 mass ppm or less.

A direct bonded copper ceramic substrate is provided, which includes a nitride ceramic substrate, a first passivation layer, and a first copper layer. The first passivation layer includes aluminum oxide or silicon oxide doped with another metal. The other metal is titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, or a combination thereof. The aluminum or silicon and the other metal have a weight ratio of 60:40 to 99.5:0.5. The first passivation layer is disposed between the top surface of the nitride ceramic substrate and the first copper layer.