Eddy Current Analysis in the Capacitor Discharge Welding

Abstract

The capacitor discharge welding (CDW) process is an autogenous, high-energy density, rapid solidification joining process. It is considered as an electrical resistance welding process since the heat source is the joule effect induced by a capacitive discharge at the welding contact zone. It is an ideal process for joining small parts incorporating dissimilar metals. Potential applications include welding of solderless electrical contacts, welding of thermocouple wire-to-wire or wire-to-plate structure and capacitor discharge (CD) stud welding. Due to the very short time of performing the capacitor discharge; a huge magnetic field is erected around the welded parts, and consequently a huge amount of eddy current is developed. The objective of the present study is to analytically investigate the role of generated eddy current in the CDW process when used in welding two thermocouple wires. A mathematical model is developed to evaluate the intensity of the generated eddy current when the capacitor is being discharged through the two metal wires. This study is counted as the first trial to consider the effect of eddy currents in the capacitor discharge welding process, which may be beneficial in computer simulation work.