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.

Systems and methods of pre-ageing of a metal strip during metal processing include passing the metal strip adjacent a magnetic rotor of a reheater. The systems and methods also include heating the metal strip through the magnetic rotor by rotating the magnetic rotor. Rotating the magnetic rotor induces a magnetic field into the metal strip such that the metal strip is heated.

A method for manufacturing a golf club head includes forming a pre-forged striking face insert from an - titanium alloy having a Molybdenum equivalency of about 6 to 12 or an Al equivalency of about 2 to 7, and forging the pre-forged striking face insert into a forged striking face insert having a specified geometry or curvature. In some embodiments, the method may also include performing only a single-step heat treatment on the striking face insert including heating the striking face insert to a temperature below a beta transus temperature of the - titanium alloy for a period of time, and thereafter cooling the striking face insert to ambient temperature. In some other embodiments, the method may further include attaching the forged striking face insert to an aft body portion to form a golf club head, and performing the single-step heat treatment and cooling on the golf club head.

A method for manufacturing a golf club head includes forming a pre-forged striking face insert from an - titanium alloy having a Molybdenum equivalency of about 6 to 12 or an Al equivalency of about 2 to 7, and forging the pre-forged striking face insert into a forged striking face insert having a specified geometry or curvature. In some embodiments, the method may also include performing only a single-step heat treatment on the striking face insert including heating the striking face insert to a temperature below a beta transus temperature of the - titanium alloy for a period of time, and thereafter cooling the striking face insert to ambient temperature. In some other embodiments, the method may further include attaching the forged striking face insert to an aft body portion to form a golf club head, and performing the single-step heat treatment and cooling on the golf club head.

A method for producing a sheet metal or strip and a sheet metal or strip produced using this method are described. For a comparatively high gloss level and a comparatively high durability, it is proposed for the sheet metal or strip made of an aluminum alloy of the EN AW-5xxx type to have a cold-rolled structure having a grain structure that is elongated in the rolling direction, with grains whose grain aspect ratio AI.sub.l=l.sub.l(0)/l.sub.l(90) is 10, more particularly 15, measured according to ASTM E112-13.

A method for producing a sheet metal or strip and a sheet metal or strip produced using this method are described. For a comparatively high gloss level and a comparatively high durability, it is proposed for the sheet metal or strip made of an aluminum alloy of the EN AW-5xxx type to have a cold-rolled structure having a grain structure that is elongated in the rolling direction, with grains whose grain aspect ratio AI.sub.l=l.sub.l(0)/l.sub.l(90) is 10, more particularly 15, measured according to ASTM E112-13.

A tungsten-containing material that has an oxygen generation quantity of more than 1 ppm and 20 ppm or less at 2100 C. to 2300 C. as detected by oxygen analysis based on an oxygen separation method, and contains 5 ppm or more and 30 ppm or less of potassium.

A production method for a negative electrode active material in the present disclosure includes: obtaining a thin piece by cooling molten metal of a hydrogen absorbing alloy containing Ti, Zr, Cr, Mn, and Ni, at a speed of 110.sup.2 C./second to 110.sup.4 C./second, at least to lower than 500 C.; and performing heat treatment of the thin piece at 500 C. to 900 C. for 1 hour to 10 hours in a vacuum or an inert gas atmosphere. The negative electrode active material obtained by the production method includes hydrogen absorbing alloy including a plurality of main phases and a grain boundary phase that exists between mutually adjacent main phases of the main phases, each of the main phases include an AB.sub.2 alloy phase, the grain boundary phase includes an AB alloy phase, and the average distance between the mutually adjacent main phases is 1.0 m or less.

A production method for a negative electrode active material in the present disclosure includes: obtaining a thin piece by cooling molten metal of a hydrogen absorbing alloy containing Ti, Zr, Cr, Mn, and Ni, at a speed of 110.sup.2 C./second to 110.sup.4 C./second, at least to lower than 500 C.; and performing heat treatment of the thin piece at 500 C. to 900 C. for 1 hour to 10 hours in a vacuum or an inert gas atmosphere. The negative electrode active material obtained by the production method includes hydrogen absorbing alloy including a plurality of main phases and a grain boundary phase that exists between mutually adjacent main phases of the main phases, each of the main phases include an AB.sub.2 alloy phase, the grain boundary phase includes an AB alloy phase, and the average distance between the mutually adjacent main phases is 1.0 m or less.

The present disclosure relates to a titanium or titanium alloy member and to a surface hardening method for the titanium or titanium alloy member. The titanium or titanium alloy member includes a base material of titanium or titanium alloy, and at a surface of the base material, a hardened layer formed by diffusion of oxygen into the surface.