METHOD FOR STACK-WELDING DISSIMILAR METAL MEMBERS

• US 20200130100A1
• Filed: 10/07/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: KOBAYASHI, Hiroomi, SHIBATA, Yoshinori, NAKAYAMA, Hiroyuki
• Granted Patent: US 11,413,706 B2
• Time in Patent Office: Days
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B23K 2103/12 Copper or alloys thereof
• CPC Class Codes: B23K 2103/18 Dissimilar materials
• CPC Class Codes: B23K 26/21 by welding
• CPC Class Codes: B23K 26/244 Overlap seam welding
• CPC Class Codes: B23K 26/323 involving parts made of dissimilar metallic material

Abstract

A method for stack-welding dissimilar metal members by placing a first metal member and a second metal member having a melting point higher than that of the first metal member on top of one another and performing laser welding is provided. The second metal member is placed on the first metal member, and a molten pool in which only the second metal member is melted is formed by applying a laser beam for thermal-conduction welding from above the second metal member. After the molten pool comes into contact with the first metal member and hence the first metal member melts in the molten pool, the molten pool solidifies, so that the first and second metal members and are welded together.

Claims

1. A method for stack-welding dissimilar metal members by placing a first metal member and a second metal member having a melting point higher than that of the first metal member on top of one another and performing laser welding, comprising

placing the second metal member on the first metal member, and forming a molten pool in which only the second metal member is melted by applying a laser beam for thermal-conduction welding from above the second metal member, wherein

after the molten pool comes into contact with the first metal member and hence the first metal member melts in the molten pool, the molten pool solidifies, so that the first and second metal members are welded together.

2. The method for stack-welding dissimilar metal members according to claim 1, wherein when the second metal member is placed on the first metal member prior to the irradiation with the laser beam, a gap is formed between the first and second metal members in a place where the laser beam is applied.

3. The method for stack-welding dissimilar metal members according to claim 1, wherein

the first metal member is made of a metallic material containing aluminum as a main component, and

the second metal member is made of a metallic material containing copper as a main component.

4. The method for stack-welding dissimilar metal members according to claim 3, wherein the laser beam is applied under a condition in which for irradiation energy [J] of the laser beam, a time [ms] from the end of the irradiation with the laser beam to the completion of the solidification of the molten pool is 0.2 [ms/J] or shorter.