Grading of Spot Welding Electrode Material Properties Using AHP

Abstract

An objective of this research is to rank the essential property required for spot welding material selection. Total ten attributes namely Electrical conductivity, Thermal conductivity, Rockwell Hardness, Wear resistance, Density, Cost, Melting point, Percentage Elongation, Yield Strength and Ultimate Tensile Strength were considered for the purpose of selection of the electrode Material. In order to select appropriate spot welding electrode, authors have studied various Copper alloys having equally good properties. The selection of essential properties was done using Analytical Hierarchy Process (AHP). Experimental work have been carried out on Cu-Cr-Zr material using universal tensile and found that the strength and hardness increases with alloying element, however percentage elongation decreases by 50 % as compared to pure Cu. While performing AHP, the authors found that electrical conductivity, wear resistance, thermal conductivity and Rockwell hardness proved to be the most crucial parameters. Wear of electrode material also affects on current density and performance characteristics of spot welding process and makes it more expensive. The ranking of the property thus provide an input to apply various Multi-Attribution Decision Making (MADM) techniques for selection of the appropriate material for spot welding application. This work is recommended to spot welding electrode manufacturers as well as end users in order to prioritize the properties for selection of spot welding electrode with longer life and good weld quality.