[Problem to be Solved]

Provided are an aluminum-silicon-carbide composite having high thermal conductivity, low thermal expansion, and low specific gravity and a method for producing the composite.

[Solution]

Provided is an aluminum-silicon-carbide composite formed by impregnating a porous silicon carbide molded body with an aluminum alloy. The ratio of silicon carbide in the composite is 60 vol % or more, and the composite contains 60-75 mass % of silicon carbide having a particle diameter of 80 m or more and 800 m or less, 20-30 mass % of silicon carbide having a particle diameter of 8 m or more and less than 80 m, and 5-10 mass % of silicon carbide having a particle diameter of less than 8

A dielectric material includes a barium titanate based base material main ingredient and an accessory ingredient. In a fine sintered structure of the dielectric material, crystal grains in which a content of Ca is less than 2.5 mol % are first crystal grains, crystal grains in which the content of Ca is 4.0 to 12.0 mol % are second crystal grains, and a ratio of an average size of the first crystal grains to an average size of the second crystal grains is in a range of 1.6 to 2.2.

A surface-coated boron nitride sintered body tool is provided, in which a cutting edge portion includes a compound sintered body and a coating layer. The compound sintered body includes cBN particles. The compound sintered body includes 45-80 vol % of cBN particles. A first particle size distribution curve of the cBN particles has one or more peaks in a range in which a particle size is 0.1-0.7 m. A second particle size distribution curve of the cBN particles has a first peak having a maximum peak height in a range in which the particle size is 2.0-7.0 m. An integral value ratio (I.sub.o/I.sub.t100) is 1-20, in the second particle size distribution curve, the integral value I.sub.o being in the range in which the particle size is 0.1-0.7 m, and the integral value I.sub.t being in an entire range.

Polycrystalline compacts include smaller and larger hard grains that are interbonded to form a polycrystalline hard material. The larger grains may be at least about 33 times larger than the smaller grains. An interstitial material comprising one or more of a boride, a carbide, a nitride, a metal carbonate, a metal bicarbonate, and a non-catalytic metal may be disposed between the grains. The compacts may be used as cutting elements for earth-boring tools such as drill bits, and may be disposed on a substrate. A particulate mixture includes a first plurality of grains of hard material having a coating formed over the grains of hard material. The coating comprises at least one of a boride, a carbide, a nitride, a metal carbonate, a metal bicarbonate, and a non-catalytic metal. A second plurality of grains of hard material has a grain size at least 33 times larger than the first plurality.

Provided is a wavelength converting member made of a sintered body which inhibits color unevenness of exit light after wavelength conversion and has excellent light emitting efficiency and inhibited decrease in mechanical strength. The wavelength converting member includes a plate-like sintered body having one principal surface as a light entrance surface and the other principal surface as a light exit surface, and a porosity of 0.1% or less with fluorescent material grains containing an activator and light-transmitting material grains, the entrance surface and the exit surface are sintered surfaces in which the fluorescent material grains and light-transmitting material grains are exposed without processing. The sintered surface has an average roughness Ra of 0.1 ?m to 0.5 ?m, the fluorescent material grains exposed on a surface have an average roughness Ra1 of 0.2 nm to 0.5 nm, and the light-transmitting material grains exposed on a surface have an average roughness Ra2 of 0.3 nm to 0.7 nm.

A refractory object can include at least 10 wt % Al.sub.2O.sub.3. In an embodiment, the refractory object can further include a dopant including an oxide of a rare earth element, Ta, Nb, Hf, or any combination thereof. In another embodiment, the refractory object may have a property such that the averaged grain size does not increase more than 500% during sintering, an aspect ratio less than approximately 4.0, a creep rate less than approximately 1.010.sup.5 m/(mhr), or any combination thereof. In a particular embodiment, the refractory object can be in the form of a refractory block or a glass overflow forming block. The glass overflow forming block can be useful in forming an AlSiMg glass sheet. In a particular embodiment, a layer including MgAl oxide can initially form along exposed surfaces of the glass overflow forming block when forming the AlSiMg glass sheet.

A dielectric material includes a barium titanate based base material main ingredient and an accessory ingredient. In a fine sintered structure of the dielectric material, crystal grains in which a content of Ca is less than 2.5 mol % are first crystal grains, crystal grains in which the content of Ca is 4.0 to 12.0 mol % are second crystal grains, and a ratio of an average size of the first crystal grains to an average size of the second crystal grains is in a range of 1.6 to 2.2.

PCBN material consisting of cBN grains dispersed in a matrix, the content of the cBN grains being in the range of about 35 to about 70 volume % of the PCBN material. The matrix comprises at least one kind of chemical compound that includes aluminum (Al) and at least one kind of chemical compound that includes titanium (Ti). The size distribution of the cBN grains exposed at a surface of the PCBN material is such that at least about 50% percent of the total equivalent circle area (ECA) arises from cBN intercept lengths up to 5 microns. At least about 20 percent of the total ECA arises from cBN intercept lengths greater than about 5 microns.

A capacitor includes a stack and an external electrode located on a surface of the stack. The stack includes a plurality of dielectric layers and a plurality of internal electrode layers alternately stacked on one another. Crystal grains include first crystal grains having a small grain size and second crystal grains having a larger grain size. The first crystal grains satisfy 0.13 md1<0.30 m, where d1 is the grain size of the first crystal grains. The second crystal grains satisfy 0.30 md2<0.50 m, where d2 is the grain size of the second crystal grains. The second crystal grains have a higher additive element content than the first crystal grains.

A silicon carbide based material exhibiting high strength, good thermal shock resistance, high resistance to abrasion and being chemically stable to harsh environmental conditions is described. The carbide Ball Hill ceramic comprises a -SiAlON bonding phase in which sintering is facilitated by at least one rare earth oxide sintering agents incorporated within the Vibrating Sieve batch admixture as starting materials. The residual rare earth sintering aid being chosen so as to impart good mechanical and refractory properties.