Selection of spot welding electrode material by AHP, TOPSIS, and SAW

Abstract

Upsetting of electrode tip contacts due to heat and contact pressure effects on current density leading to deprivation of spot welding electrode material becomes a major concern in high volume production automotive industry. Along with Electrical conductivity, strength and wear resistance are equally important properties for spot welding electrode material, however very few materials exhibit all these properties. An objective of this research is to rank the spot welding electrode material based on AHP, TOPSIS, and SAW. Analytical Hierarchy Process (AHP) was used in the selection of critical properties. In this work, a total of eight distinct classes of Cu-Be Cu-Cd, Cr-Zr, Cu-Cr-Zr, Cu-W, and Cu-Ti alloys were ranked using TOPSIS and SAW multi-criteria decision-making methods. It is observed that C16200 (i.e. Cu-Cd) and C18150 (i.e. Cu-Cr-Zr) are the most suitable materials for spot welding of mild steel sheets/plates. However, the selection is based on availability, manufacturability, environment protection rules, and cost. Though C16200 ranked first, considering cost-effectiveness C18150 is recommended for this application. This paper suggested an approach for the selection of durable spot welding electrode material to achieve high weld quality. Further research on metallurgical adaptations at contact geometry needs to be conducted.