Non-destructive testing system and method using current flow thermography

• US 20040120383A1
• Filed: 12/19/2002
• Published: 06/24/2004
• Est. Priority Date: 12/19/2002
• Status: Abandoned Application

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Kennedy, James C., Uyehara, Clyde T., Thompson, Jeffrey G.
• Application Number:
  US10/322,512
• Publication Number:
  US 20040120383A1
• Time in Patent Office: Days
• US Class Current: 374/57
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

A system and method for verifying conductive paths in test parts and for testing the conductive paths for flaws subjects the test part to a current flow from one location to another via conduction. Sites containing dislocations cause a concentration of current around them which results in increased ohmic heating which can be detected with an infrared camera.

Claims

1. A system for detecting thermal anomalies in a test part, comprising:

a first contact secured at a first location on the test part;

a second contact secured at a second location on the test part;

a current source for providing a current between said first and said second contacts through said test part; and

a camera for detecting a thermal image of the test part.

2. The system of claim 1, wherein the current source is provided by a current transformer.

3. The system of claim 2, wherein the current transformer supplies an alternating current of between 5 and 8 amperes.

4. The system of claim 2, wherein the current transformer supplies a direct current of between 5 and 8 amperes.

5. The system of claim 1, further comprising a video display device for displaying the thermal image of the test part.

6. The system of claim 5, wherein the camera also detects a visual image of the test part.

7. The system of claim 6, further comprising an image processor for overlaying said thermal image on said visual image of the test part.

8. The system of claim 5, further comprising a video camera for detecting a visual image of the test part.

9. The system of claim 8, further comprising an image processor for overlaying said thermal image on said visual image of the test part.

10. The system of claim 5, further comprising an image processor for overlaying said thermal image of said test part onto a computer-aided design (CAD) drawing of the test part.

11. A system for detecting thermal anomalies in a test part, comprising:

a first contact secured at a first location on the test part;

a second contact secured at a second location on the test part;

a current supplying means for supplying a current between said first and said second contacts through said test part; and

a detecting means for detecting a thermal image of the test part.

12. The system of claim 11, wherein the detecting means is a first liquid crystal sheet attached to the test part.

13. The system of claim 12, wherein said first liquid crystal sheet is attached to the test part by vacuum.

14. The system of claim 12, wherein at least one second additional liquid crystal sheet, having different temperature sensitivities than said first sheet, is also attached to the test part.

15. The system of claim 11, wherein said current supply means is a magnetic particle machine.

16. A method of detecting thermal anomalies in a test part, comprising the steps of:

passing an electrical current through a test part to cause ohmic heating of the test part; and

detecting a thermal image of the test part.

17. The method of claim 16, further comprising the step of displaying said thermal image on a display device.

18. The method of claim 17, further comprising the step of detecting a visual image of the test part.

19. The method of claim 18, further comprising the step of overlaying one of the thermal image and the visual image onto the other of the thermal image and the visual image.

20. The method of claim 18, further comprising the step of storing at least one of the visual image and the thermal image.