Spot weld bonding

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Spot welding is the combination of structural bonding, the bonding of large, crash-relevant body parts, with the joining process of spot welding .

This required a new generation of crash-proof adhesives , which have only been available and in use since the late 1990s. In addition to high strengths and a high stiffening effect , these also have sufficiently large elongations at break even in the event of sudden loads (especially in a road traffic accident ) in the entire relevant temperature range. For a long time, problems were primarily caused by the low temperature ranges in which the adhesives exhibited brittle behavior when subjected to sudden loads. This disadvantage was minimized by the crash-stable adhesives.

Work steps

  1. Apply adhesive (layer thicknesses 0.1 to 0.3 mm depending on the area of ​​application)
  2. Fix the attachment by spot welding (in the pasty state of the adhesive)
  3. Curing of the adhesive (at room temperature or in curing ovens up to approx. 180 ° C)

Areas of application

Automobile manufacturing

The main area of ​​application is the shell construction / body construction in automobile production, where a wide variety of materials have to be connected to one another and the focus is on weight reduction, cost reduction and high performance of the joined connections.

Spot welding performance

For example, spot-welded connections are combined with stitched-seam structure gluing, which can implement glued seam interruptions for the weld points through appropriate programming of the control of a suitable application system. This combines the advantages of both processes and avoids unpleasant, health-endangering decomposition products of the adhesive caused by burning when the welding points are set. The advantages of the adhesive connection can be fully exploited thanks to the elimination of the disadvantage of a lack of immediate strength through spot welding.

Reduce costs through spot welding

The reduction in the number of weld points through spot weld bonding means enormous savings in process time and thus money. For each weld point saved, the process time is reduced by around 3 seconds.

Weight savings through spot welding

Adhesive joints can be applied with very thin substrate thicknesses and have a lower density than metal. Due to their strong stiffening effect, the material thicknesses of the metallic materials used, such as high-strength steels, can be further reduced through the use of flat bonding. A weight saving is achieved which, thanks to the flat adhesive connection, does not come at the expense of component stiffness. The loss of component stiffness with decreasing material thickness is due to the geometrical moment of inertia .

See also

literature

  • Detlef Symietz; Andreas Lutz: Structural bonding in vehicle construction. Properties, applications and performance of a new joining process. In: Die Bibliothek der Technik , Verlag Moderne Industrie, 2006, ISBN 978-3-937889-43-6
  • Holger Thommes: Evaluation of material and process-specific influences on the quality and the connection strength of spot-welded, high-strength thin steel sheets , Shaker-Verlag, 2010, ISBN 978-3-832288-29-7
  • H. Stepanski, Spot welding in the automotive industry - How it began, adhesion kleben + dichten 5/2010
  • H. Stepanski, Spot Welding in Automobile Construction - The Path to Series Production, adhesion kleben + dichten 6/2010