Joined body of dissimilar metals and method for producing joined body of dissimilar metals

Patent metadata

Field	Value
Publication number	US-10076799-B2
Application number	US-201415036246-A
Country	US
Kind code	B2
Filing date	Dec 26, 2014
Priority date	Jan 21, 2014
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A joined body of dissimilar metals, in which a flared joint is formed and which have a high joint strength, is provided. The joined body contains a first metal member having a curved surface portion, a second metal member having a higher melting point than the first metal member and joined to the first metal member to form the flared joint, and a joining metal portion formed by irradiating the first metal member and a filler material disposed between the first and second metal members with a laser. An intermetallic compound formed at the interface between the second metal member and the joining metal portion has a thickness of at most 3 μm. A melted portion and a non-melted portion are formed in the curved surface portion of the first metal member in which the flared joint is formed.

First claim

The invention claimed is:

1. A joined body of dissimilar metals, comprising:
a first metal member having a curved surface portion;
a second metal member having a higher melting point than the first metal member and joined to the first metal member to form a flared joint; and
a joining metal portion formed by irradiating a filler material and the first metal member with a laser, the filler material being disposed at a lap portion where the first metal member is joined to the second metal member,
wherein
the first metal member is an aluminum alloy member,
the second metal member is a steel member,
the filler material is an aluminum-based alloy filler,
a maximum thickness of an intermetallic compound formed at an interface between the second metal member and the joining metal portion is 3 μm or less,
in the curved surface portion of the first metal member on which the flared joint is formed, a melted portion and a non-melted portion are formed in this order in a cross-sectional direction of the first metal member from the side of the first metal member on which the joining metal portion is formed,
the melted portion has a depth d 2 and the non-melted portion has a depth d 1 , d 1 and d 2 being measured in the cross-sectional direction of the first metal member and satisfying 0.5≤d 1 /(d 1 +d 2 )≤0.9, and
in a direction in which the second metal member extends in a flared manner, a maximum length of a region in which the second metal member and the joining metal portion are joined to each other is 2 to 4 mm.

2. The joined body according to claim 1 , wherein a bend radius of the curved surface portion of the first metal member is 0.5 to 5 mm.

3. A method for producing a joined body of dissimilar metals, the method comprising:
placing a filler material in a lap portion where a first metal member having a curved surface portion is joined to a second metal member having a higher melting point than the first metal member to form a flared joint; and
irradiating the filler material and the first metal member with a laser beam at an irradiation angle inclined by 15 degrees or less with respect to a joint surface of the flared joint to form a joining metal portion,
wherein
the first metal member is an aluminum alloy member,
the second metal member is a steel member,
the filler material is an aluminum-based alloy filler,
a maximum thickness of an intermetallic compound formed at an interface between the second metal member and the joining metal portion is 3 μm or less,
in the curved surface portion of the first metal member on which the flared joint is formed, a melted portion and a non-melted portion are formed in this order in a cross-sectional direction of the first metal member from the side of the first metal member on which the joining metal portion is formed,
the melted portion has a depth d 2 and the non-melted portion has a depth d 1 , d 1 and d 2 being measured in the cross-sectional direction of the first metal member and satisfying 0.5≤d 1 /(d 1 +d 2 )≤0.9, and
in a direction in which the second metal member extends in a flared manner, a maximum length of a region in which the second metal member and the joining metal portion are joined to each other is 2 to 4 mm.

4. The method according to claim 3 , wherein during the irradiating, the laser beam is shifted toward the first metal member side from a position where the filler material is disposed.

5. The method according to claim 4 , wherein the laser beam has a beam diameter of 0.1 to 3.0 mm.

Assignees

• Kobe Steel Ltd

Inventors

• Kaitoku Kazumasa
• Matsumoto Tsuyoshi
• Eguchi Noritaka
• Hashimura Toru

Classifications

• B23K1/19 Primary

  taking account of the properties of the materials to be soldered · CPC title

• B23K1/0056 Primary

  soldering by means of beams, e.g. lasers, electron beams [EB] · CPC title

• B23K2103/20

  Ferrous alloys and aluminium or alloys thereof · CPC title

• B23K2101/006

  Vehicles · CPC title

• B23K26/323

  involving parts made of dissimilar metallic material · CPC title