Measurement of contact parameters at electrode/sheet interface during resistance spot welding process

Abstract The numerical simulation of the resistance spot welding process requires a precise understanding of the thermal conditions at the electrode/sheet interface. This necessitates a knowledge of the thermal contact resistance RTC which prevails at the interface, and the partition coefficient of generated heat flux at the interface α. This coefficient draws its significance from the non-conservative character of the generated heat flux in the disturbed zone of the contact. Consequently, on the macroscopic scale, only a fraction α (α< 1) of the heat flux generated at the interface contributes to the temperature change at the electrode/sheet interface. The present work reports an experimental study relating to the simultaneous estimation of RTC and α at the electrode/sheet interface during the resistance spot welding process. Both parameters, RTC and α, depend on the electrode/sheet interface structure. Consequently, RTC and α are time dependent during the welding process. The results of measurement of t...