Interfacial microstructure and optimization of friction welding by Taguchi and ANOVA method on SA 213 tube to SA 387 tube plate without backing block using an external tool

摘要

The materials technology plays a tremendous development in the field of engineering in recent days. Friction welding is a vital solid state joining technique for both similar and dissimilar materials. In this present investigation, Friction welding is carried out to weld two dissimilar materials of SA 213 tube to SA 387 tube plate using an external tungsten carbide tool to enhance and validate the mechanical and metallurgical properties. The Taguchi L9 orthogonal array is used to optimize the process parameters to obtain better joint strength and ANOVA method is applied to determine the percentage contribution of each process parameter. The regression equation is formulated for two conditions of the work pieces to obtain the maximum welding joint strength and it is verified by the confirmation test. This is followed by the micro structural studies to reveal about the welding configuration which is capable of producing defect-free welds. In addition, hardness and compression strength of welds were obtained with nine different work pieces with various conditions. The two kinds of materials are taken in this investigation, where type 1 is tube without hole and type 2 is tube with hole on its circumference. It was observed that the optimal joint strength for the work piece without hole and with hole are 3062 MPa and 2845 MPa respectively. The value of Vickers hardness test was found in the welded zone to be much greater in work piece without hole that the work piece with hole are 313 Hv and 283 Hv respectively. (C) 2015 Elsevier B.V. All rights reserved.