Copper alloy sheet material and method for producing same, and current-carrying component

Patent metadata

Field	Value
Publication number	US-2016201179-A1
Application number	US-201414912641-A
Country	US
Kind code	A1
Filing date	Aug 26, 2014
Priority date	Aug 30, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

A copper alloy sheet material contains, in mass %, Fe: 0.05 to 2.50%, Mg: 0.03 to 1.00%, and P: 0.01 to 0.20%, and the contents of these elements satisfy the relation Mg-1.18(P—Fe/3.6) 3 0.03. The Mg solid-solution ratio determined by the amount of dissolved Mg (mass %)/the Mg content of the alloy (mass %)’ 100 is 50% or more. The density of an Fe—P-based compound having a particle size of 50 nm or more is 10.00 particles/10 mm 2 or less, and the density of an Mg—P-based compound having a particle size of 100 nm or more is 10.00 particles/10 mm 2 or less. The Cu—Fe—P—Mg-based copper alloy sheet material is excellent in terms of electrical conductivity, strength, bending workability, and stress relaxation resistance in the case where load stress is applied in a direction perpendicular to both a rolling direction and a sheet thickness direction.

First claim

1 . A copper alloy sheet material comprising, in mass %, Fe: 0.05 to 2.50%, Mg: 0.03 to 1.00%, P: 0.01 to 0.20%, Sn: 0 to 0.50%, Ni: 0 to 0.30%, Zn: 0 to 0.30%, Si: 0 to 0.10%, Co: 0 to 0.10%, Cr: 0 to 0.10%, B: 0 to 0.10%, Zr: 0 to 0.10%, Ti: 0 to 0.10%, Mn: 0 to 0.10%, and V: 0 to 0.10%, the balance being Cu and inevitable impurities, and having a chemical composition that satisfies the following equation (1),
the copper alloy sheet material being such that when the average Mg concentration (mass %) in a Cu matrix part determined by EDX analysis through TEM observation at a magnification of 100,000 is defined as the amount of dissolved Mg, the Mg solid-solution ratio defined by the following equation (2) is 50% or more, the density of an Fe—P-based compound having a particle size of 50 nm or more is 10.00 particles/10 μm 2 or less, and the density of an Mg—P-based compound having a particle size of 100 nm or more is 10.00 particles/10 μm 2 or less:
Mg-1.18(P—Fe/3.6)≧0.03 . . .   (1)

Mg solid-solution ratio(%)=the amount of dissolved Mg (mass %)/the total Mg content (mass %)×100 . . .   (2),

wherein the element symbols Mg, P, and Fe in the equation (1) are substituted with the contents of the respective elements in mass %.

2 . The copper alloy sheet material according to claim 1 , having the following properties:
an electrical conductivity of 65% IACS or more; when the rolling direction is defined as LD, and the direction perpendicular to both the rolling direction and the thickness direction is defined as TD, a 0.2% offset yield strength in LD of 450 N/mm 2 or more in accordance with JIS Z2241; bending workability such that no cracking is observed in a W bending test in accordance with JIS Z3110 under conditions where the bending axis is LD and the ratio R/t between the bending radius R and the thickness t is 0.5; and a stress relaxation ratio of 35% or less in the case where, in a cantilever stress relaxation test using a specimen whose longitudinal direction agrees with LD and width in TD is 0.5 mm, a load stress of 80% of the 0.2% offset yield strength in LD is applied to the specimen in such a manner that the direction of deflection displacement being imparted is TD, followed by holding at 150° C. for 1,000 hours.

3 . A method for producing a copper alloy sheet material, comprising:
a casting step of solidifying a melt of a copper alloy in a mold, followed by a cooling process such that the average cooling rate from 700 to 300° C. is 30° C./min or more to produce a slab, the copper alloy containing, in mass %, Fe: 0.05 to 2.50%, Mg: 0.03 to 1.00%, P: 0.01 to 0.20%, Sn: 0 to 0.50%, Ni: 0 to 0.30%, Zn: 0 to 0.30%, Si: 0 to 0.10%, Co: 0 to 0.10%, Cr: 0 to 0.10%, B: 0 to 0.10%, Zr: 0 to 0.10%, Ti: 0 to 0.10%, Mn: 0 to 0.10%, and V: 0 to 0.10%, the balance being Cu and inevitable impurities, and having a chemical composition that satisfies the following equation (1); a slab-heating step of heating and holding the obtained slab at a range of 850 to 950° C.; a hot rolling step of hot rolling the heated slab at a final pass temperature of 400 to 700° followed by rapid cooling such that the average cooling rate from 400 to 300° C. is 5° C./sec or more to produce a hot-rolled sheet; a cold rolling step of rolling the hot-rolled sheet to a rolling ratio of 30% or more; a first intermediate annealing step of raising the temperature to a holding temperature T° C. within a range of 600 to 850° C. such that the average temperature rise rate from 300° C. to T° C. is 5° C./sec or more, and holding the sheet at T° C. for 5 to 300 sec, followed by cooling such that the average cooling rate from T° C. to 300° C. is 5° C./sec or more; a second intermediate annealing step of holding the sheet at a range of 400 to 590° C. for 0.5 h or more, followed by cooling such that the average cooling rate from the holding temperature to 300° C. is 20 to 200° C./h; a finish cold rolling step of rolling the sheet to a rolling ratio of 5 to 95%; and a low-temperature annealing step of heating the sheet at 200 to 400° C.:
Mg-1.18(P—Fe/3.6)≧0.03 . . .   (1),

wherein the element symbols Mg, P, and Fe in the equation (1) are substituted with the contents of the respective elements in mass %.

4 . An electric current-carrying component obtained by processing the copper alloy sheet material of claim 1 or 2 , for use under load stress applied in a direction in the component derived from the direction (TD) perpendicular to both the rolling direction and the thickness direction of the copper alloy sheet material.

Assignees

• Dowa Metaltech Co Ltd

Inventors

• MIYAGI Kuniaki
• Suga Takashi
• Aoyama Tomotsugu
• Narieda Hiroto
• Endo Hideki
• Sugawara Akira

Classifications

• C22F1/002

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• H01B1/026

  Alloys based on copper · CPC title

• C22C9/00

  Alloys based on copper · CPC title

• C22C9/02

  with tin as the next major constituent · CPC title

• C22F1/08 Primary

  of copper or alloys based thereon · CPC title