The effect of mechanical loading on the contact resistance of coated aluminium

doi:10.1016/S0921-5093(97)00020-8

Materials Science and Engineering: A

Volume 230, Issues 1–2, 1 July 1997, Pages 194-201

https://doi.org/10.1016/S0921-5093(97)00020-8 Get rights and content

Abstract

Measurements of contact resistance, related to resistance spot welding, were made using pre-treated (coated) and abraded aluminium alloy strip. With conventional domed electrodes, the contact resistance was much larger at the sheet-to-sheet (faying) contact than at the electrode-sheet contact. The effect is believed to be associated with the role of sliding in breaking down contact resistance of sheet with an insulating surface film. When the coating was removed the difference between faying surface and electrode-sheet contact was much smaller. Macroscopic shear stresses are developed by electrode-sheet contact whereas no shear stresses are present at the faying surface. The hypothesis is supported by experiments made with asymmetrical electrode pairs which give rise to varying shear stresses in faying surface contact. Some implications for the control of spot welding of different aluminium surfaces are discussed.

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In this study, we present an improved representation of both electrical and thermal contact conditions in the numerical simulation of Al to zinc-coated steel RSW process. The electrical contact resistance (ECR) is calculated based on analytical formulations and referencing experimentally measured resistance curves from the work of James et al. [12], Song et al. [15] and Rogeon et al. [11]. The calculation deals with three interfaces separately and considers the effects of contact pressure, temperature, zinc coating and oxide.
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¹: Present address: Department of Engineering, University of Aberdeen, AB9 1FX, UK.

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The effect of mechanical loading on the contact resistance of coated aluminium

Abstract

Surf. Coat. Technol.

American Welding Society: Welding Research Supplement of The Welding Journal

American Welding Society: Welding Research Supplement of The Welding Journal

American Welding Society: Welding Research Supplement of The Welding Journal

American Welding Society: Welding Research Supplement of The Welding Journal

Optimisation and validation of a model to predict the spot weldability lobes for aluminium automotive sheet, IBEC, Nov. 1995, Detroit

Advanced Technologies and Processes

Electricity

Electrical Contacts, Theory and Applications