Methods for friction stir welding involving dissimilar materials

Patent metadata

Field	Value
Publication number	US-12459052-B2
Application number	US-202318494648-A
Country	US
Kind code	B2
Filing date	Oct 25, 2023
Priority date	Sep 12, 2016
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

Methods are provided for connecting two dissimilar materials. The methods can include: placing a first material within a groove of a second material, the first material leaving at least a portion of the groove vacant; and placing a third material upon the first material and over the groove; heating the second and third materials to a temperature sufficient to plasticize the second and third materials within the groove and form a mixture of the second and third materials within the groove. Friction stir welding tools are also provided that can include a frusta conical tip having an upper portion defining smooth sidewalls and a lower portion defining a roughened structure.

First claim

What is claimed is:

1 . A method, comprising:
bonding a first material within a groove of a second material using first friction stir welding, wherein a portion of the first material is then removed leaving at least a portion of the groove vacant; placing a third material upon the second material and over the groove, wherein the second and third materials are materials of different composition having different melting points; and using second friction stir welding to heat a mixture of the first material and the second material formed using the first friction stir welding to a temperature sufficient to plasticize and form a bond between the mixture of the first and second materials, and the third material.

2 . The method of claim 1 , wherein the first and third materials are the same materials.

3 . The method of claim 1 , wherein the heat is controlled to prevent overheating.

4 . The method of claim 1 , wherein the first and third materials are aluminum alloys.

5 . The method of claim 1 , wherein the groove defines a dovetail.

6 . The method of claim 1 , wherein the third material is extruded into the groove during the second friction stir welding.

7 . The method of claim 1 , wherein the first material is metallurgically bonded to a base of the groove of the second material due to heat associated with the first friction stir welding.

8 . The method of claim 1 , wherein the vacant portion occupies an upper portion of the groove opposite a base of the groove.

9 . The method of claim 8 , wherein the third material fills at least a portion of the upper portion of the groove.

10 . The method of claim 1 , wherein the vacant portion defines a trapezoid.

11 . The method of claim 1 , wherein the vacant portion defines a rectangle.

12 . A method, comprising:
bonding a first material within a groove of a second material using first friction stir welding; removing an upper portion of the first material opposite the second material from the groove, the removed upper portion leaving a vacant portion of the groove; placing a third material upon the second material and over the groove, wherein the second and third materials are materials of different composition having different melting points; and using second friction stir welding to heat a mixture of the first material and the second material formed using the first friction stir welding to a temperature sufficient to plasticize and form a bond between the mixture of the first and second materials, and the third material.

13 . The method of claim 12 , wherein a lower portion of the first material remaining in the groove is metallurgically bonded to the second material by the first friction stir welding.

14 . The method of claim 12 , wherein the vacant portion is at a depth that is half a total depth of the groove.

15 . The method of claim 12 , wherein the second friction stir welding is performed using a friction stir welding device that extends beyond a thickness of the third material into the groove.

16 . The method of claim 15 , wherein the friction stir welding device extends beyond the thickness of the third material into the groove to a specified plunge depth to cause a particular amount of strength and ductility.

Assignees

• Battelle Memorial Institute

Inventors

• Whalen Scott A
• Reza-E-Rabby M D
• Ross Kenneth A
• Mcdonnell Martin
• Hovanski Yuri

Classifications

• B32B15/012 Primary

  one layer being formed of an iron alloy or steel, another layer being formed of aluminium or an aluminium alloy · CPC title

• B23K2103/20

  Ferrous alloys and aluminium or alloys thereof · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title

• B23K2103/10

  Aluminium or alloys thereof · CPC title

• B32B7/08

  by mechanical means · CPC title