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 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%.

The present invention relates to metal alloys including copper.

The present invention relates to metal alloys including copper.

Provided is a metallic fastener member which has a specific color, i.e., a light gold color, and has all of practical strength, unsusceptibility to discoloration, and processability. The metallic fastener member comprises, as the base material, a copper alloy having a composition which contains 1-30 mass % Zn and 1-11 mass % Ni, with the remainder comprising Cu and unavoidable impurities, and has a Vickers hardness of 120 Hv or greater but less than 220 Hv.

Provided is a metallic fastener member which has a specific color, i.e., a light gold color, and has all of practical strength, unsusceptibility to discoloration, and processability. The metallic fastener member comprises, as the base material, a copper alloy having a composition which contains 1-30 mass % Zn and 1-11 mass % Ni, with the remainder comprising Cu and unavoidable impurities, and has a Vickers hardness of 120 Hv or greater but less than 220 Hv.

The invention relates to a copper alloy having the following composition (in % by weight): from 10.6 to 18% of Al, from 10.5 to 14.5% of Ni, optionally up to 2% of Fe, optionally up to 1% of Co, optionally up to 0.5% of Ti, optionally up to 0.5% of Mn, optionally up to 0.15% of B, optionally up to 0.1% of Ca, optionally up to 0.1% of C,

a balance copper and unavoidable impurities. Nickel aluminides of the NiAl type are embedded as precipitates in the microstructure of the alloy. The invention further relates to a number of uses of this copper alloy.

The invention relates to a copper alloy having the following composition (in % by weight): from 10.6 to 18% of Al, from 10.5 to 14.5% of Ni, optionally up to 2% of Fe, optionally up to 1% of Co, optionally up to 0.5% of Ti, optionally up to 0.5% of Mn, optionally up to 0.15% of B, optionally up to 0.1% of Ca, optionally up to 0.1% of C,

a balance copper and unavoidable impurities. Nickel aluminides of the NiAl type are embedded as precipitates in the microstructure of the alloy. The invention further relates to a number of uses of this copper alloy.

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.