Ultrasonic Characterization of Spot Welds

  • F. Nadeau
  • C. Néron
  • J. F. Bussière


Resistance welding is one of the most widely used joining processes in industry. Basically, it uses mechanical pressure and high intensity current to hold and weld sheet metal assemblies. The bond is assured by the presence of a “weld nugget”, a volume common to both sheets which melts and resolidifies during the operation. The most common application is automotive engineering where many of the sheet steel components are spot welded1. It is also used in other fields such as the aerospace industry and with other materials such as aluminum or magnesium alloys, copper, nickel, etc.2. As any other industrial process, a whole area of technologies has evolved along with resistance welding to meet requirements of quality assurance via either process control or product testing. The major breakthroughs are on the side of process control where much of the research efforts have been concentrated. Parameters such as current and time can now be dynamically controlled through adaptive feedback mechanisms using sensors that measure electrical resistance,3,4 displacement,5 infrared radiation,6 ultrasonic transmission7 and even acoustic emission.8 As for testing, most of it is still done destructively. A common method is the peel test where a sample weld is simply pulled apart: if the weld is good, one of the sheets will tear around the nugget whose width can then be measured.


Acoustic Emission Spot Weld Parent Metal Resistance Spot Weld Penetration Weld 


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  1. 1.
    Dickinson, D.W., “Welding in the Automative Industry — State of the Art”. American Iron and Steel Institute, Washington, Research Report #SG-81–5 (August 1981).Google Scholar
  2. 2.
    “Resistance and Solid-State Welding and Other Joining Processes”, A.W.S. Welding Handbook, 7th Edition, Vol. 3, pp. 14–15, W.H. Kearns Editor.Google Scholar
  3. 3.
    Dickinson, D.W., Franklin, J.E. and Stanya, A., “Characterization of Spot Welding Behavior of Dynamic Electrical Parameter Monitoring”, Welding Journal Research Supplement (June 1980), pp. 170–176.Google Scholar
  4. 4.
    Schumacher, B.W., Cooper, J.G. and Dilay, W., “Resistance Spot Welding Control That Automatically Selects the Welding Schedule for Different Types of Steel”, S.A.E. Technical Paper #850407, International Congress & Exposition, Detroit (March 1985).CrossRefGoogle Scholar
  5. 5.
    Roden, W.A., “Evaluation of Resistance Welding In-Process Monitors”, Welding Journal Research Supplement, (November 1968), pp. 515-S–521-S.Google Scholar
  6. 6.
    Brown, B. and Bawgs, E., “The Measurement and Monitoring of Resistance Spot Welds Using Infrared Thermography”, SPIE Vol. 581, Thermosense VIII (1986), pp. 57–69.Google Scholar
  7. 7.
    Burbank, G.E. & Taylor, W.D., “Ultrasonic In-Process Inspection of Resistance Spot Welds”, Welding Journal Research Suppl. (May 1965), p. 193s.Google Scholar
  8. 8.
    Havens, J.R., “Controlling Spot Welding Quality and Expulsion”, S.M.E. Paper #AD76–279 (1976).Google Scholar
  9. 9.
    Fastritsky, V.S., Fishkin, P.S. and Rybalkin, E.P., “Method and Apparatus for Non-Destructive Quality Testing of Spot Welds”, U.S. Patent #4 287 474 (Sept. 1981).Google Scholar
  10. 10.
    Cohen, R.L. and West, K.W., “Spot Weld Strength Determined from Simple Electrical Measurements”, Welding Journal Dec. 1984), pp. 17–23.Google Scholar
  11. 11.
    Papadakis, E.P., “Ultrasonic Velocity and Attenuation: Measurement Methods with Scientific and Industrial Applications”, Physical Acoustics, Vol. 12, Chapter 5, pp. 343–348, W.P. Mason & R.N. Thurston Editors, Academic Press (1976).Google Scholar
  12. 12.
    Dubetz, M. and Bilge, J.U., “Ultrasonic Method of Inspecting Spot Welds”, U.S. Patent #4 265 119 (May 1981).Google Scholar
  13. 13.
    Fendei, F., Peretz, M. and Rokhlin, S.I., “Ultrasonic Lamb Wave Method for the Sizing of Spot Welds”, Ultrasonics (March 1984), pp. 78–84.Google Scholar
  14. 14.
    Adams, T., “Nondestructive Evaluation of Resistance Spot Welding Variables Using Ultrasound”, Welding Journal (June 1985), pp. 27–28.Google Scholar
  15. 15.
    Quate, L., Atalar, A., and Wickramasinghe, H.K., Proc. IEEE (1979), Vol. 67, pp. 1092–1104.CrossRefGoogle Scholar
  16. 16.
    Papadakis, E.P., “Scattering in Polycrystalline Media”, Methods of Experimental Physics: Ultrasonics, Vol. 19, P.D. Edmons Editor, Academic Press (1981), pp. 237–278.Google Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • F. Nadeau
    • 1
  • C. Néron
    • 1
  • J. F. Bussière
    • 1
  1. 1.Industrial Materials Research InstituteNational Research Council CanadaBouchervilleCanada

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