Aluminum copper clad material

• US 9,890,438 B2
• Filed: 01/08/2016
• Issued: 02/13/2018
• Est. Priority Date: 06/08/2010
• Status: Active Grant

• Current Assignee: Hitachi Metals Limited (Hitachi Metals (Thailand) Ltd.)
• Original Assignee: Hitachi Metals Limited (Hitachi Metals (Thailand) Ltd.)
• Inventors: Oda, Yoshimitsu, Ishio, Masaaki, Hashimoto, Akio, Ikeuchi, Kenji
• Primary Examiner(s): Patel, Devang R
• Application Number:
  US14/991,255
• Publication Number:
  US 20160122842A1
• Time in Patent Office: 767 Days
• Field of Search: None
• CPC Class Codes: B23K 20/02 by means of a press ; Diffusion bonding B23K20/001, B23K20/04 take precedence
• CPC Class Codes: B32B 15/017 one layer being formed of aluminium or an aluminium alloy, another layer being formed of an alloy based on a non ferrous metal other than aluminium
• CPC Class Codes: C21D 1/26 Methods of annealing
• CPC Class Codes: C21D 9/0068 for particular articles not mentioned below
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: C22C 21/08 with silicon
• CPC Class Codes: C22C 21/10 with zinc as the next major constituent
• CPC Class Codes: C22C 21/14 with silicon
• CPC Class Codes: C22C 21/16 with magnesium
• CPC Class Codes: C22C 21/18 with zinc
• CPC Class Codes: C22C 9/00 Alloys based on copper
• CPC Class Codes: C22C 9/04 with zinc as the next major constituent
• CPC Class Codes: C22F 1/04 of aluminium or alloys based thereon
• CPC Class Codes: C22F 1/047 of alloys with magnesium as the next major constituent
• CPC Class Codes: C22F 1/053 of alloys with zinc as the next major constituent
• CPC Class Codes: C22F 1/057 of alloys with copper as the next major constituent
• CPC Class Codes: C22F 1/08 of copper or alloys based thereon
• CPC Class Codes: Y10T 428/1275 Next to Group VIII or IB metal-base component

Abstract

An aluminum copper clad material has excellent bonding strength and includes an aluminum layer and a copper layer that are bonded without a nickel layer interposed therebetween. The aluminum layer and the copper layer are diffusion-bonded via an Al—Cu intermetallic compound layer. The copper layer satisfies Dcs≦0.5×Dcc, where Dcc represents the average crystal grain size of crystal grains in a central portion in the thickness direction of the copper layer, and Dcs represents the average crystal grain size of an interface adjacent portion C2 in the copper layer that is about 0.5 μm apart from the interface between the copper layer and the intermetallic compound layer. The intermetallic compound layer has an average thickness of about 0.5 μm to about 10 μm.

Claims

1. A method for producing an aluminum copper clad material in which an aluminum layer and a copper layer are diffusion-bonded via an Al—

Cu intermetallic compound layer, the method comprising the steps of;

preparing an aluminum plate that serves as a source of the aluminum layer and a copper plate that serves as a source of the copper layer, wherein the preparing step includes completely annealing the copper plate and subjecting it to cold rolling to set an average surface hardness which satisfies Hc>

1.6×

Hca, wherein Hc (Hv) represents an average surface hardness of a surface of the copper plate to be pressure-welded, and Hca (Hv) represents an average surface hardness of the completely annealed material of the copper plate;

pressure-welding the aluminum plate and the copper plate that are stacked on each other; and

diffusion-annealing the resulting pressure-welded material at an annealing temperature T (°

C.) of about 150°

C. to about 550°

C. for an annealing time t (min) in a range satisfying the following expressions;

tmin≦

t≦

tmax

tmax=−

1.03×

T+567

tmin=0.5, when −

0.19×

T+86<

0.5,

tmin=−

0.19×

T+86, when −

0.19×

T+86≧

0.5;

wherein

in the resulting aluminum copper clad material;

the copper layer satisfies Dcs≦

0.5×

Dcc, where Dcc represents an average crystal grain size of crystal grains in a central portion in a thickness direction of the copper layer, and Dcs represents an average crystal grain size of an interface adjacent portion in the copper layer that is about 0.5 μ

m apart from an interface between the copper layer and the Al—

Cu intermetallic compound layer; and

the Al—

Cu intermetallic compound layer has an average thickness of about 0.5 μ

m to about 10 μ

m and includes broken up and dispersed aluminum oxide.

3. The method for producing the aluminum copper clad material according to claim 1, wherein the annealing temperature T (°

C.) is about 300°

C. to about 550°

C. for the annealing time t (min) in a range satisfying the following expressions;

tmin≦

t≦

tmax

tmax=−

0.90×

T+478

tmin=1.0, when −

0.36×

T+168 <

1.0

tmin=−

0.30×

T+168, when −

0.36×

T+168≧

1.0.

5. The method for producing the aluminum copper clad material according to claim 1, wherein the annealing temperature T (°

C.) is about 450°

C. or greater and about 550°

C. or less.

7. The method for producing the aluminum copper clad material according to claim 1, wherein the aluminum plate is made of pure aluminum or an aluminum alloy having an electric conductivity of about 10% IACS or greater, and the copper plate is made of pure copper or a copper alloy having an electric conductivity of about 10% IACS or greater.

2. A method for producing an aluminum copper clad material in which an aluminum layer and a copper layer are diffusion-bonded via an Al—

Cu intermetallic compound layer, the method comprising the steps of;

preparing an aluminum plate that serves as a source of the aluminum layer and a copper plate that serves as a source of the copper layer, wherein the preparing step includes completely annealing the aluminum plate and subjecting it to cold rolling to set an average surface hardness which satisfies Ha>

1.6×

Haa, where Ha (Hv) represents an average surface hardness of a surface of the aluminum plate to be pressure-welded, and Haa (Hv) represents an average surface hardness of the completely annealed material of the aluminum plate;

pressure-welding the aluminum plate and the copper plate that are stacked on each other; and

diffusion-annealing the resulting pressure-welded material at an annealing temperature T (°

C.) of about 150°

C. to about 550°

C. for an annealing time t (min) in a range satisfying the following expressions;

tmin≦

t≦

tmax

tmax=−

1.03×

T+567

tmin=0.5, when −

0.19×

T+86 <

0.5,

tmin=−

0.19×

T+86, when −

0.19×

T+86≧

0.5;

wherein

in the resulting aluminum copper clad material;

the aluminum layer satisfies Das≦

0.5×

Dac, where Dac represents an average crystal grain size of crystal grains in a central portion in a thickness direction of the aluminum layer, and Das represents an average crystal grain size of an interface adjacent portion in the aluminum layer that is about 0.5 μ

m apart from an interface between the aluminum layer and the intermetallic compound layer; and

the intermetallic compound layer has an average thickness of about 0.5 μ

m to about 10 μ

m and includes broken up and dispersed aluminum oxide.

4. The method for producing the aluminum copper clad material according to claim 2, wherein the annealing temperature T (°

C.) is about 300°

C. to about 550°

C. for the annealing time t (min) in a range satisfying the following expressions;

tmin≦

t≦

tmax

tmax=−

0.90×

T+478

tmin=1.0, when −

0.36×

T+168 <

1.0

tmin=−

0.36×

T+168, when −

0.36×

T+168≧

1.0.

6. The method for producing the aluminum copper clad material according to claim 2, wherein the annealing temperature T (°

C.) is about 450°

C. or greater and about 550°

C. or less.

8. The method for producing the aluminum copper clad material according to claim 2, wherein the aluminum plate is made of pure aluminum or an aluminum alloy having an electric conductivity of about 10% IACS or greater, and the copper plate is made of pure copper or a copper alloy having an electric conductivity of about 10% IACS or greater.