Effect of Tensile Strength on Friction Welding of Tube-to-Tube Plate Processed Samples: A Mechanical and Metallurgical Approach

The present investigation has focused on a modified Friction Stir Welding technique, namely, Friction Welding of Tube-to-tube Plate using an External Tool (FWTPET). It was applied to weld a tube plate and a tube together, enhancing their metallurgical and mechanical properties. In course of the experimentation, the authors modified a Universal Testing Machine (UTM) to conduct tensile strength tests on the tube and the plate samples. Taguchi L9 orthogonal array and genetic algorithm (GA) were applied to estimate the tensile strength. Additionally, several destructive and non-destructive tests were conducted to determine the mechanical properties. Microstructural analysis, including optical microscopy (OM), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) and x-ray diffraction (XRD), was carried out to assess the metallurgical properties and to ensure absence of any weld defects. This investigation was primarily conducted on the basis of two conditions to evaluate the welding configuration. Condition I involved a plain tube attached to the tube plate, while Condition II involved a tube with holes around its circumference. A metrological clearance fit and a backing block were also used in this operation.