According to one embodiment, a thermoelectric material are provided. The thermoelectric material includes a sintered body formed of p-type and n-type thermoelectric materials for the thermoelectric conversion element. The thermoelectric materials have a MgAgAs type crystal structure as a main phase. An area ratio of internal defects of the thermoelectric materials for one thermoelectric conversion element is 10% or less in terms of a total area ratio of defective portions in a scanning surface according to ultrasonic flaw detection in a thickness direction of the thermoelectric material. No defect having a length of 800 ?m or more is present at any vertex of chips of the thermoelectric materials.

According to one embodiment, a thermoelectric material are provided. The thermoelectric material includes a sintered body formed of p-type and n-type thermoelectric materials for the thermoelectric conversion element. The thermoelectric materials have a MgAgAs type crystal structure as a main phase. An area ratio of internal defects of the thermoelectric materials for one thermoelectric conversion element is 10% or less in terms of a total area ratio of defective portions in a scanning surface according to ultrasonic flaw detection in a thickness direction of the thermoelectric material. No defect having a length of 800 ?m or more is present at any vertex of chips of the thermoelectric materials.

According to one embodiment, a ceramic copper circuit board a ceramic substrate, a copper circuit board provided at one surface of the ceramic substrate. A ratio of a thickness of the copper circuit board to a thickness of the ceramic substrate is 1.25 or more. A number of grain boundaries is not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper circuit board.

According to one embodiment, a ceramic copper circuit board a ceramic substrate, a copper circuit board provided at one surface of the ceramic substrate. A ratio of a thickness of the copper circuit board to a thickness of the ceramic substrate is 1.25 or more. A number of grain boundaries is not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper circuit board.

A conductive ball includes a copper ball, a nickel layer covering an outer surface of the copper ball, a copper layer covering an outer surface of the nickel layer, and a tin-based solder covering an outer surface of the copper layer. A copper weight of the copper layer relative to a summed weight of the tin-based solder and the copper layer is 0.7 wt % to 3 wt %.

A conductive ball includes a copper ball, a nickel layer covering an outer surface of the copper ball, a copper layer covering an outer surface of the nickel layer, and a tin-based solder covering an outer surface of the copper layer. A copper weight of the copper layer relative to a summed weight of the tin-based solder and the copper layer is 0.7 wt % to 3 wt %.

A sintered bearing exhibits less of a hard iron alloy phase, and has an excellent wear resistance and cost performance under low-revolution and high-load use conditions; and a method for producing such a sintered bearing. The sintered bearing contains Cu: 10 to 55% by mass, Sn: 0.5 to 7% by mass, Zn: 0 to 4% by mass, P: 0 to 0.6% by mass, C: 0.5 to 4.5% by mass and a remainder composed of Fe and inevitable impurities. An area ratio of a free graphite dispersed in a metal matrix of the bearing is 5 to 35%; a porosity thereof is 16 to 25%; a hardness of an iron alloy phase in the matrix is Hv 65 to 200; and raw material powders employ at least one of a crystalline graphite powder and a flake graphite powder each having an average particle size of 10 to 100 m.

A group of substantially nickel-free beta-titanium alloys have shape memory and super-elastic properties suitable for, e.g., medical device applications. In particular, the present disclosure provides a titanium-based group of alloys including 16-20 at. % of hafnium, zirconium or a mixture thereof, 8-17 at. % niobium, and 0.25-6 at. % tin. This alloy group exhibits recoverable strains of at least 3.5% after axial, bending or torsional deformation. In some instances, the alloys have a capability to recover of more than 5% deformation strain. Niobium and tin are provided in the alloy to control beta phase stability, which enhances the ability of the materials to exhibit shape memory or super-elastic properties at a desired application temperature (e.g., body temperature). Hafnium and/or zirconium may be interchangeably added to increase the radiopacity of the material, and also contribute to the superelasticity of the material.

Provided is an alloy comprising eight or more types of constituent elements, wherein the relative difference in terms of distance between nearest neighbors DNN between a constituent element having the largest distance between nearest neighbors DNN when constituting a bulk crystal from a single element and a constituent element having the smallest distance between nearest neighbors DNN when constituting a bulk crystal from a single element is 9% or less, the number of constituent elements having the same crystal structure when constituting a bulk crystal from a single element is not more than 3, and the difference in concentration between the constituent element having the highest concentration and the constituent element having the lowest concentration is 2 at. % or lower.

Provided is an alloy comprising eight or more types of constituent elements, wherein the relative difference in terms of distance between nearest neighbors DNN between a constituent element having the largest distance between nearest neighbors DNN when constituting a bulk crystal from a single element and a constituent element having the smallest distance between nearest neighbors DNN when constituting a bulk crystal from a single element is 9% or less, the number of constituent elements having the same crystal structure when constituting a bulk crystal from a single element is not more than 3, and the difference in concentration between the constituent element having the highest concentration and the constituent element having the lowest concentration is 2 at. % or lower.