Provided are a high-strength and high-conductivity Cu—Ag—Sc alloy and a preparation method thereof. The preparation method includes the following steps: (1) placing metal Ag and metal Sc in an electric-arc furnace and performing smelting under a vacuum condition, performing cooling to normal temperature in the furnace to obtain an Ag—Sc intermediate alloy; (2) placing the Ag—Sc intermediate alloy, an electrolytic copper and the metal Ag in an induction furnace and performing heating to 1200-1300° C. under a vacuum condition, keeping at the temperature for 10-60 min for smelting, then performing casting and cooling to normal temperature in the furnace to obtain ingots; (3) heating the ingots to 700-850° C. under an inert atmosphere, then performing water quenching to normal temperature to obtain heat-treated ingots; and (4) heating the heat-treated ingots to 400-500° C. under an inert atmosphere, then performing air cooling to normal temperature to obtain the high-strength and high-conductivity Cu—Ag—Sc.

Provided is a current detection resistor, such as a shunt resistor, wherein a. low specific resistance and a small thermal electromotive force with respect to copper are achieved, while maintaining a low TCR. A resistance alloy for use in a current detection shunt resistor includes 4.5 to 5.5 mass % of manganese, 0.05 to 0.30 mass % of silicon, 0.10 to 0.30 mass % of iron, and a balance being copper, and has a specific resistance of 15 to 25 μΩ.Math.m.

Provided is a current detection resistor, such as a shunt resistor, wherein a. low specific resistance and a small thermal electromotive force with respect to copper are achieved, while maintaining a low TCR. A resistance alloy for use in a current detection shunt resistor includes 4.5 to 5.5 mass % of manganese, 0.05 to 0.30 mass % of silicon, 0.10 to 0.30 mass % of iron, and a balance being copper, and has a specific resistance of 15 to 25 μΩ.Math.m.

A slit copper material, a purity of Cu is comprises 99.96% by mass or greater of Cu. In this slit copper material, a ratio W/t of a plate width W to a plate thickness t is 10 or greater, an electrical conductivity is 97.0% IACS or greater, a ratio B/A of an average crystal grain size B in a plate surface layer portion to an average crystal grain size A in a plate center portion is in a range of 0.80 or greater and 1.20 or less, and the average crystal grain size A in the plate center portion is 25 μm or less.

A slit copper material, a purity of Cu is comprises 99.96% by mass or greater of Cu. In this slit copper material, a ratio W/t of a plate width W to a plate thickness t is 10 or greater, an electrical conductivity is 97.0% IACS or greater, a ratio B/A of an average crystal grain size B in a plate surface layer portion to an average crystal grain size A in a plate center portion is in a range of 0.80 or greater and 1.20 or less, and the average crystal grain size A in the plate center portion is 25 μm or less.

A method of refining a microstructure of a titanium material can include providing a solid titanium material at a temperature below about 400° C. The titanium material can be heated under a hydrogen-containing atmosphere to a hydrogen charging temperature that is above a β transus temperature of the titanium material and below a melting temperature of the titanium material, and held at this temperature for a time sufficient to convert the titanium material to a substantially homogeneous β phase. The titanium material can be cooled under the hydrogen-containing atmosphere to a phase transformation temperature below the β transus temperature and above about 400° C., and held for a time to produce α phase regions. The titanium material can also be held under a substantially hydrogen-free atmosphere or vacuum at a dehydrogenation temperature below the β transus temperature and above the δ phase decomposition temperature to remove hydrogen from the titanium material.

A method of refining a microstructure of a titanium material can include providing a solid titanium material at a temperature below about 400° C. The titanium material can be heated under a hydrogen-containing atmosphere to a hydrogen charging temperature that is above a β transus temperature of the titanium material and below a melting temperature of the titanium material, and held at this temperature for a time sufficient to convert the titanium material to a substantially homogeneous β phase. The titanium material can be cooled under the hydrogen-containing atmosphere to a phase transformation temperature below the β transus temperature and above about 400° C., and held for a time to produce α phase regions. The titanium material can also be held under a substantially hydrogen-free atmosphere or vacuum at a dehydrogenation temperature below the β transus temperature and above the δ phase decomposition temperature to remove hydrogen from the titanium material.

A tungsten wire according to an embodiment is a tungsten wire made of a W alloy containing rhenium, and includes a mixture on at least a part of a surface thereof, the mixture contains W, C, and O as constituent elements, and taking a radial cross-sectional thickness of the mixture as A mm and a diameter of the tungsten wire as B mm, an average value of a ratio A/B of A to B is 0.3% to 0.8%.

A tungsten wire according to an embodiment is a tungsten wire made of a W alloy containing rhenium, and includes a mixture on at least a part of a surface thereof, the mixture contains W, C, and O as constituent elements, and taking a radial cross-sectional thickness of the mixture as A mm and a diameter of the tungsten wire as B mm, an average value of a ratio A/B of A to B is 0.3% to 0.8%.

There is provided a copper alloy bonded body composed of a plurality of members made of an age-hardenable copper alloy, the members diffusion-bonded to one another. The copper alloy bonded body has undergone solution annealing and an aging treatment, the content of beryllium in the age-hardenable copper alloy is 0.7% by weight or less, and (i) a bonding interface between the members has disappeared and/or (ii) a bonding interface between the members remains, and an oxide film at the bonding interface has a thickness of 0 nm or more and 5.0 nm or less.