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Abstract: The
effect of electrode pitting on the welding quality in resistance spot
welding (RSW) of aluminum alloy AA5182 is investigated using both finite
element analysis and physical modeling methods. Results show that with
the increasing of the pitted area at the electrode tip, the actual
contact area at electrode/sheet interface does not change so much, while
the contact area at sheet/sheet interface is increased significantly,
therefore, the current density at the sheet/sheet interface is reduced
greatly, and the thickness and diameter of the nugget formed are both
decreased. Dimensions and shapes of the nuggets from physical modeling
are in very good coincidence with numerical predictions. Only a donut
shape nugget with very limited thickness is formed when the diameter of
the pitting hole is 5.0 mm. These results reveal that the increasing of
contact area at sheet/sheet interface by the increasing pitting hole
diameter at the electrode tip is one of the major causes for worse and
worse welding quality during RSW of aluminum alloys.
Key words: Resistance
spot welding Electrode pitting FEM modeling Aluminum alloys
CLC No: TG402
国家教育部留学回国人员科研启动基金资助项目.
Received 20030326, received in revised form 20031008
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