Method for the detection of a possible joint defect in a friction stir weld seam

Patent metadata

Field	Value
Publication number	US-9182299-B2
Application number	US-201213479423-A
Country	US
Kind code	B2
Filing date	May 24, 2012
Priority date	May 27, 2011
Publication date	Nov 10, 2015
Grant date	Nov 10, 2015

Abstract

The disclosure provides methods for the detection of a possible joint defect, in particular a root fusion defect, in a friction stir weld seam, wherein two members are joined together and the methods include generating of a tensile stress in the region of the friction stir weld seam in the elastic range, and testing in at least some regions of a lower face of the friction stir weld seam, in order to detect any joint defect.

First claim

The invention claimed is:

1. A method for the detection of a possible joint defect in a friction stir weld seam, by means of which two members are joined together, each member of the two members being made of material, the method comprising:
a) generating a tensile stress below an elastic limit of the materials of each member in the region of the friction stir weld seam to bend open any joint defect;
b) testing in at least some regions of a lower face of the friction stir weld seam, in order to detect any joint defect; and
c) before step a):
applying a pattern to at least some regions of the lower face of the friction weld seam, and
taking a reference image from the pattern, wherein the pattern includes a primer with an irregular pattern of points applied to it.

2. The method in accordance with claim 1 , further comprising:
before step a) applying a penetrating dye to the lower face of the friction stir weld seam.

3. The method in accordance with claim 2 , wherein the testing step includes a dye penetration test.

4. The method in accordance with claim 1 , further comprising:
after step a) taking a measured image of the pattern.

5. The method in accordance with claim 4 , wherein the testing step includes a comparison of the measured image with the reference image.

6. The method in accordance with claim 1 , further comprising:
before step a) taking a reference image of the lower face of the friction stir weld seam by shearography.

7. The method in accordance with claim 6 , further comprising:
after step a) obtaining a measured image of the lower face of the friction stir weld seam by shearography.

8. The method in accordance with claim 7 , wherein the testing step includes a comparison of the measured image with the reference image.

9. The method in accordance with claim 1 , further comprising:
after step a) obtaining a measured image of the lower face of the friction stir weld seam by shearography.

10. The method in accordance with claim 9 , wherein the testing step includes a direct visual evaluation of the measured image.

11. The method in accordance with claim 1 , wherein the generating step includes generating by bending the joined members over an edge, wherein the edge is arranged in a region of an upper face of the friction stir weld seam, and the edge rests against at least some regions of the latter.

12. The method in accordance with claim 1 , wherein the generating step includes generating a negative pressure p u in the region of the lower face of the friction stir weld seam.

13. The method in accordance with claim 1 , wherein the generating step includes generating by bending two outer member edges upwards in the same direction.

Assignees

• Syassen Freerk
• Airbus Operations Gmbh

Inventors

• Syassen Freerk

Classifications

• G01N21/91 Primary

  using penetration of dyes, e.g. fluorescent ink · CPC title

• G01N21/95

  characterised by the material or shape of the object to be examined (G01N21/89 - G01N21/91, G01N21/94 take precedence) · CPC title

• G01L1/00 Primary

  Measuring force or stress, in general (measuring force due to impact G01L5/00) · CPC title

• G01N2203/0296

  Welds · CPC title

• G01N2021/8829

  Shadow projection or structured background, e.g. for deflectometry · CPC title