The present invention provides a thermally deformable annular packer with pressure relief means for use in oil and gas wells. The annular packer is formed from a stack of component parts, said parts comprising one or more eutectic alloy based ring sections sandwiched between two end sections. At least one of the annular packer component parts has one or more enclosed voids that are configured to become exposed when the packer is subjected to a predetermined pressure or temperature. The exposure of the enclosed voids serves to increase the effective volume within the sealed region formed by the annular packer in the annulus between two coaxial well casing/tubing. The increase in the effective volume serves to reduce the pressure within the sealed region thus preventing a build-up of pressure that might otherwise have damaged the well casing/tubing.

[Object] To improve both abrasion resistance and seizure resistance.

[Solution] A copper alloy sliding material is configured, which contains 0.5 to 12.0 mass % of Sn, 2.0 to 8.0 mass % of Bi, and 1.0 to 5.0 vol % of an inorganic compound, the balance being Cu and inevitable impurities, wherein the inorganic compound includes a first inorganic compound having an average particle size of 0.5 to 3.0 μm and a second inorganic compound having an average particle size of 4.0 to 20.0 μm, and wherein a value obtained by dividing a volume fraction of the first inorganic compound by a volume fraction of the second inorganic compound is 0.1 to 1.0.

[Object] To improve both abrasion resistance and seizure resistance.

[Solution] A copper alloy sliding material is configured, which contains 0.5 to 12.0 mass % of Sn, 2.0 to 8.0 mass % of Bi, and 1.0 to 5.0 vol % of an inorganic compound, the balance being Cu and inevitable impurities, wherein the inorganic compound includes a first inorganic compound having an average particle size of 0.5 to 3.0 μm and a second inorganic compound having an average particle size of 4.0 to 20.0 μm, and wherein a value obtained by dividing a volume fraction of the first inorganic compound by a volume fraction of the second inorganic compound is 0.1 to 1.0.

A core material has a core 12; a solder layer 16 made of a (Sn—Bi)-based solder alloy provided on an outer side of the core 12; and a Sn layer 20 provided on an outer side of the solder layer 16. The core contains metal or a resin. When a concentration ratio of Bi contained in the solder layer 16 is a concentration ratio (%)=a measured value of Bi (% by mass)/a target Bi content (% by mass), or a concentration ratio (%)=an average value of measured values of Bi (% by mass)/a target Bi content (% by mass), the concentration ratio is 91.4% to 106.7%. The thickness of the Sn layer 20 is 0.215% or more and 36% or less of the thickness of the solder layer 16.

A thermoelectric conversion material includes a sintered body including a main phase including a plurality of crystal grains including Ce, Mn, Fe, and Sb and forming a skutterudite structure, and a grain boundary between crystal grains adjacent to each other. The grain boundary includes a sintering aid phase including at least Mn, Sb, and O. Thus, with respect to a skutterudite-type thermoelectric conversion material including Sb, which is a sintering-resistant material, it is possible to improve sinterability while maintaining a practical dimensionless figure-of-merit ZT, and to reduce processing cost.

Disclosed is a technology of permanently phase-transiting a semimetal using ion implantation. More particularly, the permanent phase transition of a dirac semimetal into a weyl semimetal can be induced by implanting non-magnetic material ions into the dirac semimetal according to an embodiment.

Disclosed is a technology of permanently phase-transiting a semimetal using ion implantation. More particularly, the permanent phase transition of a dirac semimetal into a weyl semimetal can be induced by implanting non-magnetic material ions into the dirac semimetal according to an embodiment.

An object of the present invention is to provide an Sn—Bi—Cu—Ni solder alloy or the like which has a low melting point, excellent ductility, and high tensile strength, and in which if soldering is performed on a Cu electrode subjected to electroless Ni plating treatment, a solder joint formed through this soldering exhibits high shear strength. In addition, another object of the present invention is to provide an Sn—Bi—Cu—Ni solder alloy in which a solder joint formed through soldering exhibits high shear strength even for a Cu electrode which has not been subjected to plating treatment. Furthermore, still another object of the present invention is to provide, in addition to the above-described objects, a solder alloy or the like of which yellowish discoloration can be suppressed and in which change in viscosity of a solder paste over time can be suppressed. The solder alloy has an alloy composition consisting of, by mass %, 31% to 59% of Bi, 0.3% to 1.0% of Cu, 0.01% to 0.06% of Ni, 0.0040% to 0.025% of As, and a balance of Sn.

An object of the present invention is to provide an Sn—Bi—Cu—Ni solder alloy or the like which has a low melting point, excellent ductility, and high tensile strength, and in which if soldering is performed on a Cu electrode subjected to electroless Ni plating treatment, a solder joint formed through this soldering exhibits high shear strength. In addition, another object of the present invention is to provide an Sn—Bi—Cu—Ni solder alloy in which a solder joint formed through soldering exhibits high shear strength even for a Cu electrode which has not been subjected to plating treatment. Furthermore, still another object of the present invention is to provide, in addition to the above-described objects, a solder alloy or the like of which yellowish discoloration can be suppressed and in which change in viscosity of a solder paste over time can be suppressed. The solder alloy has an alloy composition consisting of, by mass %, 31% to 59% of Bi, 0.3% to 1.0% of Cu, 0.01% to 0.06% of Ni, 0.0040% to 0.025% of As, and a balance of Sn.

A piston for an internal combustion engine may include a piston crown having a closed circumferential cooling channel, a piston skirt, a first metallic coolant arranged in the cooling channel and having a metal or metal alloy with a melting point below 250° C., and a second nonmetallic coolant arranged in the cooling channel and having a melting point below 40° C. and a density which is lower than a density of the first coolant.