Friction stir welding of corner configurations

• US 6,676,008 B1
• Filed: 04/30/2002
• Issued: 01/13/2004
• Est. Priority Date: 04/30/2002
• Status: Active Grant

• Current Assignee: Edison Welding Institute Incorporated
• Original Assignee: Edison Welding Institute Incorporated
• Inventors: Skilliter, Mathew, Stotler, Timothy, Trapp, Timothy J.
• Primary Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US10/135,259
• Time in Patent Office: 623 Days
• Field of Search: 228/49.4, 228/112.1, 228/2.1, 228/44.3, 228/49.1, 428/544, 428/615
• US Class Current: 228/112.1
• CPC Class Codes: B23K 20/1255 Tools therefor, e.g. characterised by the shape of the probe
• CPC Class Codes: B23K 20/126 Workpiece support, i.e. backing or clamping
• CPC Class Codes: B23K 20/1265 Non-butt welded joints, e.g. overlap-joints, T-joints or spot welds

Abstract

A radiused corner support plate is used to form a corner void when making L- and T-corner welds that are filled with plasticized work piece material during friction stir welding to form a filleted corner weld. An improved friction stir welding tool uses either disrupting features such as crossed rectangular grooves in the distal tip end or a curved tip region or both to improve plasticized work piece material flow below the distal end and in the region of the fillet.

Claims

1. A friction stir welding setup for corner welds comprising:

a) a corner support plate comprising;

1) a horizontal portion;

2) an angled portion;

3) a radiused outer corner;

b) a first work piece secured to said angled portion of said corner support plate;

c) a second work piece secured to said horizontal corner support plate and in proximity with said first work piece and forming a corner void with said radiused outer corner of said corner support plate;

d) a friction stir weld tool for joining said first work piece to said second work piece in a region where said first work piece and said second work piece are in proximity with each other and filling said corner void with plasticized first work piece and second work piece material.

2. The friction stir welding setup for corner welds according to claim 1 wherein:

a) said first work piece extends above the horizontal portion of said corner support plate by an amount equal to the thickness of said second work piece; and

b) an end of the second work piece butts against the face of said first work piece extending above said horizontal portion of said corner support plate.

3. The friction stir welding setup for corner welds according to claim 1 wherein:

a) an end of said first work piece is substantially flush with the upper surface of said horizontal portion of said corner support plate; and

b) the underside of said second work piece butts against said end of said first work piece flush with said upper surface of said horizontal portion of said corner support plate.

4. The friction stir welding setup for corner welds according to claim 3 further comprising:

a) a second corner support plate comprising;

1) a horizontal portion;

2) an angled portion; and

3) a radiused outer corner;

b) said first work piece secured to said angled portion of said second corner support plate on the side of said first work piece opposite said other corner support plate so that the upper surface of said horizontal portion of said second corner support plate is substantially flush with said end of said first work piece.

5. The friction stir welding setup for corner welds according to claim 4 wherein said second work piece comprises two work piece sections in end-to-end proximity relation with each other such that the ends are substantially centered over the end of the first work piece.

6. The friction stir welding setup for corner welds according to claim 4 wherein said friction stir weld tool has a rounded distal end that extends into the end of said first work piece.

7. The friction stir welding setup for corner welds according to claim 4 wherein said friction stir weld tool has a curved end region that extends into the end of said first work piece.

8. The friction stir welding setup for corner welds according to claim 7 wherein said curved end region has a curvature that conforms to the curvature of said outer corner of said corner support plate.

9. The friction stir welding setup for corner welds according to claim 1 with said friction stir weld tool comprising disrupting features formed in the distal end of said tool.

10. The friction stir weld tool according to claim 9 wherein said disrupting features comprise notches formed in said distal end.

11. The friction stir weld tool according to claim 9 wherein said disrupting features comprise grooves formed in said distal end.

12. The friction stir weld tool according to claim 11 wherein two grooves are formed in said distal end.

13. The friction stir weld tool according to claim 12 wherein said two grooves cross at substantially right angles to each other.

14. The friction stir weld tool according to claim 13 wherein said two grooves are rectangular grooves.

15. The friction stir weld tool according to claim 14 wherein said distal end is a rounded end.

16. A friction stir weld tool for joining work pieces at a corner comprising:

a) a cylinder having;

1) a first end portion for attachment to a rotating drive;

2) a second opposite end probe portion with a distal end;

b) said second opposite end probe portion having formed in said distal end disrupting features that increase the flow of plasticized metal in the region at the end of said distal end, wherein said disrupting features comprise two rectangular grooves that cross at essentially right angles to each other.

17. The friction stir weld tool according to claim 16 wherein said distal end is a rounded end.

18. A method for producing corner welds using friction stir welding, said method comprising the steps of:

a) providing a corner support plate comprising;

1) a horizontal portion;

2) an angled portion;

3) a radiused outer corner;

b) securing a first work piece to said angled portion of said corner support plate;

c) securing a second work piece to said horizontal corner support plate and in proximity with said first work piece so as to form a corner void with said radiused outer corner of said corner support plate;

d) plasticizing said first work piece and said second work piece in a region where said first work piece and said second work piece are in proximity with each other so as to fill said corner void with plasticized first work piece and second work piece material with a friction stir weld tool; and

e) removing said corner support plate from said first work piece and said second work piece to provide a fillet corner weld.

19. The method for producing corner welds using friction stir welding according to claim 18 further comprising the steps of:

a) positioning said first work piece so that it extends above the horizontal portion of said corner support plate by an amount equal to the thickness of said second work piece; and

b) positioning an end of the second work piece against the face of said first work piece extending above said horizontal portion of said corner support plate.

20. The method for producing corner welds using friction stir welding according to claim 18 further comprising the steps of:

a) positioning an end of said first work piece so that it is substantially flush with the upper surface of said horizontal portion of said corner support plate; and

b) positioning the underside of said second work piece so that it is against said end of said first work piece.

21. The method for producing corner welds using friction stir welding according to claim 20 further comprising the steps of:

a) providing a second corner support plate comprising;

1) a horizontal portion;

2) an angled portion; and

3) a radiused outer corner;

b) securing said first work piece to said angled portion of said second corner support plate on the side of said first work piece opposite said other corner support plate so that the upper surface of said horizontal portion of said second corner support plate is substantially flush with said end of said first work piece.

22. The method for producing corner welds using friction stir welding according to claim 21 further comprising the step of providing a rounded distal end on said friction stir weld tool that extends into the end of said first work piece.

23. The method for producing corner welds using friction stir welding according to claim 21 further comprising the step of providing a curved tip region on said friction stir weld tool that extends into the end of said first work piece.

24. The method for producing corner welds using friction stir welding according to claim 23 wherein said curved tip region has a curvature that conforms to the curvature of said outer corner of said corner support plate.

25. The method for producing corner welds using friction stir welding according to claim 18 further comprising the step of forming two rectangular grooves crossing at right angles to each other in the distal end of said friction stir welding tool.

26. A friction stir weld tool for joining work pieces at a corner comprising:

a) a cylinder having;

1) a first end portion for attachment to a rotating drive;

2) a second opposite end probe portion with a rounded distal end further comprising disrupting features that increase the flow of plasticized metal in the region beyond said distal end, wherein said disrupting features comprise two rectangular grooves formed in said distal end that cross at essentially right angles to each other;

b) said second opposite end probe portion having formed therein a curved tip region, said curved tip region having a shoulder and a curved transition geometry for reducing the distal end region of said probe to a smaller probe diameter.