Copper alloy with high strength and excellent processability in bending and process for producing copper alloy sheet

Patent metadata

Field	Value
Publication number	US-9976208-B2
Application number	US-201414583894-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Jul 7, 2005
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

The present invention provides a Cu—Fe—P alloy which has a high strength, high conductivity and superior bending workability. The copper alloy comprises 0.01 to 1.0% Fe, 0.01 to 0.4% P, 0.1 to 1.0% Mg, and the remainder Cu and unavoidable impurities. The size of oxides and precipitates including Mg in the copper alloy is controlled so that the ratio of the amount of Mg measured by a specified measurement method in the extracted residue by a specified extracted residue method to the Mg content in said copper alloy is 60% or less, thus endowing the alloy with a high strength and superior bending workability.

First claim

The invention claimed is:

1. A method for manufacturing a plate of a copper alloy, said copper alloy comprising copper and alloying elements Fe in 0.01 to 1.0% by mass, P in 0.01 to 0.4% by mass, and Mg in 0.1 to 1.0% by mass, wherein said method comprises:
casting, hot rolling, cold rolling and annealing said copper alloy, wherein a time from completion of addition of the alloying elements to the copper in a melting furnace to an initiation of casting said copper alloy into an ingot is 1200 seconds or less and a cooling rate is 0.1° C./sec or greater, and wherein a time from an ejection of the ingot from a heating furnace to a completion of said hot rolling is 1200 seconds or less,
wherein the plate of a copper alloy produced by said method has a ratio of an amount of Mg in an extracted residue from said plate of a copper alloy produced by said method to an Mg content in said plate of a copper alloy produced by said method of 0.60 or less; wherein
said extracted residue is obtained by immersing 10 g of said plate of a copper alloy in 300 ml of a methanol solution with a 10 mass % concentration of ammonium acetate, performing constant-current electrolysis at a current density of 10 mA/cm 2 using said plate of a copper alloy as an anode and using platinum as a cathode to dissolve said plate of a copper alloy, and suction filtering said solution in which said plate of a copper alloy is dissolved using a polycarbonate membrane filter with an opening size of 0.1 μm to provide said extracted residue on said filter; and
said amount of Mg in said extracted residue is determined by inductively coupled plasma emission sectroscopy following dissolution of said extracted residue with a solution in which aqua regia and water are mixed at a ratio of 1 to 1.

2. The method according to claim 1 , wherein said method further comprises a second cold rolling after said annealing, and
wherein a temperature upon completion of said hot rolling is 550° C. to 850° C., a cold rolling reduction is 70 to 98%, a mean heating rate in the annealing is set at 50° C./s or greater, a mean cooling rate following the annealing is 100° C./s or greater, and a second cold rolling reduction is 10 to 30%.

3. The method according to claim 1 , wherein said alloying elements further comprise Ni or Co, or both, in a content by mass of 0.01 to 1.0%.

4. The method according to claim 1 , wherein said alloying elements further comprise Zn in a content by mass of 0.005 to 3.0%.

5. The method according to claim 1 , wherein said alloying elements further comprise Sn in a content by mass of 0.01 to 5.0%.

6. The method according to claim 1 , wherein said alloying elements further comprise Mn or Ca, or both, at a total content of 0.0001 to 1.0% by mass.

7. The method according to claim 1 , wherein said alloying elements further comprise one or more elements selected from a set of Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au and Pt at a total content of 0.001 to 1.0% by mass.

8. The method according to claim 1 , wherein said alloying elements further comprise Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B or mischmetal so that the total content of the elements is 0.1 by mass or less.

9. The method according to claim 1 , wherein the time from the completion of the addition of the alloying elements to the copper to the initiation of casting said copper alloy into an ingot is 1100 seconds or less and the time from the ejection of the ingot from the heating furnace to the completion of said hot rolling is 1100 seconds or less.

10. The method according to claim 1 , wherein the plate of a copper alloy produced by said method has a mean grain size of 6.5 μm or less, wherein said grain size is measured by a crystal orientation analysis method in which an electron back scattering pattern system is mounted on a field emission scanning electron microscope, using the following expression:
mean grain size=(Σ x )/ n

where n indicates the number of crystal grains measured and x indicates the grain size values measured, and wherein a standard deviation of the mean grain size is 1.5 μm or less, calculated using the following expression:
[ nΣx 2 −(Σ x ) 2 ]/[n /( n− 1) 1/2 ]

where n indicates the number of crystal grains measured and x indicates the grain size values measured.

11. The method according to claim 1 , wherein the plate of a copper alloy produced by said method has a ratio of an amount of Mg in an extracted residue from said plate of a copper alloy produced by said method to an Mg content in said plate of a copper alloy produced by said method of 0.22-0.60.

Assignees

• Kobe Steel Ltd

Inventors

• Aruga Yasuhiro
• Kajihara Katsura
• Kudo Takeshi

Classifications

• B22D21/025

  Casting heavy metals with high melting point, i.e. 1000 - 1600 degrees C, e.g. Co 1490 degrees C, Ni 1450 degrees C, Mn 1240 degrees C, Cu 1083 degrees C · CPC title

• B22D11/004

  Copper alloys · CPC title

• C22C9/05

  with manganese as the next major constituent · CPC title

• C22C1/06

  with the use of special agents for refining or deoxidising · CPC title

• C22F1/08 Primary

  of copper or alloys based thereon · CPC title