Abstract: A copper alloy consisting of two or more of Cr, Ti and Zr, and the balance Cu and impurities, in which the relationship between the total number N and the diameter X satisfies the following formula (1). Ag, P, Mg or the like may be included instead of a part of Cu. This copper alloy is obtained by cooling a bloom, a slab, a billet, or a ingot in at least in a temperature range from the bloom, the slab, the billet, or the ingot temperature just after casting to 450° C., at a cooling rate of 0.5° C./s or more. After the cooling, working in a temperature range of 600° C. or lower and further heat treatment of holding for 30 seconds or more in a temperature range of 150 to 750° C. are desirably performed. The working and the heat treatment are desirably performed a plurality of times. log N?0.4742+17.629×exp(?0.

Abstract: A copper alloy consisting of two or more of Cr, Ti and Zr, and the balance Cu and impurities, in which the relationship between the total number N and the diameter X satisfies the following formula (1). Ag, P, Mg or the like may be included instead of a part of Cu. This copper alloy is obtained by cooling a bloom, a slab, a billet, or a ingot in at least in a temperature range from the bloom, the slab, the billet, or the ingot temperature just after casting to 450° C., at a cooling rate of 0.5° C./s or more. After the cooling, working in a temperature range of 600° C. or lower and further heat treatment of holding for 30 seconds or more in a temperature range of 150 to 750° C. are desirably performed. The working and the heat treatment are most desirably performed for a plurality of times. log N?0.4742+17.629×exp(?0.

Abstract: A copper alloy consisting of two or more of Cr, Ti and Zr, and the balance Cu and impurities, in which the relationship between the total number N and the diameter X satisfies the following formula (1). Ag, P, Mg or the like may be included instead of a part of Cu. This copper alloy is obtained by cooling a bloom, a slab, a billet, or a ingot in at least in a temperature range from the bloom, the slab, the billet, or the ingot temperature just after casting to 450° C., at a cooling rate of 0.5° C./s or more. After the cooling, working in a temperature range of 600° C. or lower and further heat treatment of holding for 30 seconds or more in a temperature range of 150 to 750° C. are desirably performed. The working and the heat treatment are desirably performed a plurality of times. log N?0.4742+17.629×exp(?0.

Abstract: A copper alloy material consists of, by mass % Ti: 0.01-2.5%, Cr: 0.01-0.5%, Fe: 0.01% or more and less than 1%, and the balance Cu and impurities. The copper alloy possesses excellent strength, electrical conductivity, and workability without containing any environmentally harmful elements. These properties are attained by control of the total number and the diameter of precipitates and inclusions having a diameter of 1 ?m, and control of the relationship between tensile strength TS (MPa) and electrical conductivity, IACS (%). The copper alloy material is a sheet and the relationship between tensile strength and the bending workability in a bad way B90 of the copper alloy material as well as the relationship between elongation and tensile strength are also controlled with respect to each other for property improvement.

Abstract: A copper alloy that has a specific chemical composition, the balance being Cu and impurities, in which the relationship between the total number N and the diameter X satisfies the following formula (1). This copper alloy is obtained by cooling a bloom, a slab, a billet or an ingot in at least a temperature range from the temperature of the bloom, the slab, the billet or the ingot just after casting to 450° C., at a cooling rate of 0.5° C./s or more. After the cooling, working in a temperature range of 600° C. or lower and further heat treatment of holding for 30 seconds or more in a temperature range of 150 to 750° C. are desirably performed. The working and the heat treatment are most desirably performed for a plurality of times. log N<0.4742+17.629×exp(?0.

Abstract: A copper alloy consisting of two or more of Cr, Ti and Zr, and the balance Cu and impurities, in which the relationship between the total number N and the diameter X satisfies the following formula (1). Ag, P, Mg or the like may be included instead of a part of Cu. This copper alloy is obtained by cooling a bloom, a slab, a billet, or a ingot in at least in a temperature range from the bloom, the slab, the billet, or the ingot temperature just after casting to 450° C., at a cooling rate of 0.5° C./s or more. After the cooling, working in a temperature range of 600° C. or lower and further heat treatment of holding for 30 seconds or more in a temperature range of 150 to 750° C. are desirably performed. The working and the heat treatment are most desirably performed for a plurality of times. log N?0.4742+17.629×exp(?0.