Resistance Spot Welding Lab Report

In this article the influence of the important resistance spot welding process parameters on the shear-tensile strength of the welded joints of Inconel alloy 625 was investigated. Experimental study using full factorial design of the welding current, welding time, and electrode force parameters was conducted. In order to identify the influence of each parameter and their interaction a general linear model and a second order model using response surface method was developed. Nonlinear correlation was observed between the welding process parameters and spot weld strength based on the regression outcomes. To raise the accuracy of the statistical model, the artificial neural network was employed. The R2 equal to 98.11% of the model confirmed the
1- Introduction
Resistance spot welding (RSW) is a quick process with the automation ability with minimum environmental pollution. This method is extensively applied to joint sheet metal in industries. The process uses two shaped copper alloy electrodes to concentrate welding current into a small "spot" and to simultaneously clamp the sheets together. The weld is made by a combination of heat, pressure, and time. As the name resistance welding implies, it is the resistance of the material to be welded to current flow that causes a localized heating in the part. The pressure exerted by the tongs and electrode tips, through which the current flows, holds the parts to be welded in intimate contact before, during, and after the welding current time cycle [1]. Due to the large application of spot welding in different industries such as automobile manufacturing and aerospace, investigation on the effects of process parameters of RSW on the joint strength has attracted a great deal of tending [2-4]. Eisazadeh et al. conducted a parametric study of nugget size in the resistance spot welding process. They provided a methodology to predict the quality and
Inconel is a family of austenite nickel-chromium-based super-alloys which are used for its high strength, excellent fabricability (including joining), and outstanding corrosion resistance [21]. According to the literature, it was discovered that the welding time, welding current and electrode force are the main affecting factors on the spot weld strength. But the obtained results vary in different cases and the interactions between these parameters were not discovered completely. In order to model the effects of welding process parameters on the weld joint strength, an experimental study was conducted using full factorial design. The shear-tensile test was employed as an appropriate test method for examining the spot weld strength. Consequently, several modeling procedures were employed to model the effects of process parameters and assess the effectiveness of the parameters and their interactions on the spot weld