A spinodal copper-nickel-tin alloy with a combination of improved impact strength, yield strength, and ductility is disclosed. The alloy is formed by process treatment steps including solution annealing, cold working and spinodal hardening. These include such processes as a first heat treatment/homogenization step followed by hot working, solution annealing, cold working, and a second heat treatment/spinodally hardening step. The spinodal alloys so produced are useful for applications demanding enhanced strength and ductility such as for pipes and tubes used in the oil and gas industry.

A Cu-based sintered sliding member that can be used under high-load conditions. The sliding member is age-hardened, including 5 to 30 mass % Ni, 5 to 20 mass % Sn, 0.1 to 1.2 mass % P, and the rest including Cu and unavoidable impurities. In the sliding member, an alloy phase containing higher concentrations of Ni, P and Sn than their average concentrations in the whole part of the sliding member, is allowed to be present in a grain boundary of a metallic texture, thereby achieving excellent wear resistance. Hence, without needing expensive hard particles, there can be obtained, at low cost, a Cu-based sintered sliding member usable under high-load conditions. Even more excellent wear resistance is achieved by containing 0.3 to 10 mass % of at least one solid lubricant selected from among graphite, graphite fluoride, molybdenum disulfide, tungsten disulfide, boron nitride, calcium fluoride, talc and magnesium silicate mineral powders.

A Cu-based sintered sliding member that can be used under high-load conditions. The sliding member is age-hardened, including 5 to 30 mass % Ni, 5 to 20 mass % Sn, 0.1 to 1.2 mass % P, and the rest including Cu and unavoidable impurities. In the sliding member, an alloy phase containing higher concentrations of Ni, P and Sn than their average concentrations in the whole part of the sliding member, is allowed to be present in a grain boundary of a metallic texture, thereby achieving excellent wear resistance. Hence, without needing expensive hard particles, there can be obtained, at low cost, a Cu-based sintered sliding member usable under high-load conditions. Even more excellent wear resistance is achieved by containing 0.3 to 10 mass % of at least one solid lubricant selected from among graphite, graphite fluoride, molybdenum disulfide, tungsten disulfide, boron nitride, calcium fluoride, talc and magnesium silicate mineral powders.

A method for forming a QCr0.8 alloy tapered cylindrical ring, including: heating a standard QCr0.8 alloy cylindrical part followed by upsetting and stretching at least twice to obtain a primary blank; heating the primary blank followed by upsetting and chamfering to obtain a secondary blank, where a diameter of a top end is greater than that of a bottom end; subjecting the secondary blank to backward extrusion to form a preform; machining the preform to remove a flash and a bottom residue; subjecting a bottom end of the preform to local bulging to enable a shape and a size thereof to match that of a drive roller in a forming tooling, so as to form a profiled ring blank; and rolling the profiled ring blank by a radial-axial ring rolling machine with the forming tooling to form the tapered cylindrical ring.

Guitar strings made of a magnetic copper-nickel-tin-manganese alloy are disclosed. Also disclosed are processing steps that can be performed to fabricate the guitar strings from the alloy. Further described herein are alternative uses for the strings on other electric stringed instruments.

A copper alloy containing Ni: 1.5%-3.6% and Si: 0.3%-1.0% in terms of mass percent with the remainder consisting of copper and unavoidable impurities, wherein: the average crystal grain size of the crystal grains in the copper alloy is 5 to 30 μm; the area ratio of the crystal grains having crystal grain sizes not less than twice the average crystal grain size is not less than 3%; and the ratio of the area of cube orientation grains to the area of the crystal grains having crystal grain sizes not less than twice the average crystal grain size is not less than 50%.

A metal matrix self-lubricating composite and a manufacturing method therefor. The metal matrix self-lubricating composite comprises a metal matrix and a mixture layer compounded on a surface of the metal matrix, the mixed layer comprising a copper alloy and a self-lubricating material. The method for manufacturing the metal matrix self-lubricating composite comprises the following steps: a) sintering copper alloy powder on a surface of a metal matrix to form a copper alloy layer on the surface of the metal matrix; b) blade-coating or dip-coating a lubricating material on a surface of the copper alloy layer, and performing vacuumization to obtain a metal plate, and drying the metal plate; c) repeating step b) for multiple times; and d) sintering the metal plate obtained in step c) to obtain the metal matrix self-lubricating composite. In the present invention, a vacuumization mode is used and vacuumization operations are repeated, so that a dense mixture layer on which a self-lubricating material is dispersed on a copper alloy is formed, and the metal matrix self-lubricating composite has good lubricity and abrasion resistance.

A metal matrix self-lubricating composite and a manufacturing method therefor. The metal matrix self-lubricating composite comprises a metal matrix and a mixture layer compounded on a surface of the metal matrix, the mixed layer comprising a copper alloy and a self-lubricating material. The method for manufacturing the metal matrix self-lubricating composite comprises the following steps: a) sintering copper alloy powder on a surface of a metal matrix to form a copper alloy layer on the surface of the metal matrix; b) blade-coating or dip-coating a lubricating material on a surface of the copper alloy layer, and performing vacuumization to obtain a metal plate, and drying the metal plate; c) repeating step b) for multiple times; and d) sintering the metal plate obtained in step c) to obtain the metal matrix self-lubricating composite. In the present invention, a vacuumization mode is used and vacuumization operations are repeated, so that a dense mixture layer on which a self-lubricating material is dispersed on a copper alloy is formed, and the metal matrix self-lubricating composite has good lubricity and abrasion resistance.

Copper alloys exhibiting enhanced oxidation resistance are provided by adding an amount of sulfur that is effective to enhance oxidative resistance. Such sulfur addition can be achieved by combining elemental forms of copper and sulfur and heating the mixture to form a molten alloy, or by forming a sulfur-rich pre-mix that is added to a base alloy composition. Forming a pre-mix provides improved homogeneity and distribution of the sulfur predominantly in the form of a metal sulfide.

Copper alloys exhibiting enhanced oxidation resistance are provided by adding an amount of sulfur that is effective to enhance oxidative resistance. Such sulfur addition can be achieved by combining elemental forms of copper and sulfur and heating the mixture to form a molten alloy, or by forming a sulfur-rich pre-mix that is added to a base alloy composition. Forming a pre-mix provides improved homogeneity and distribution of the sulfur predominantly in the form of a metal sulfide.