INVESTIGATIONS OF ULTRASONIC ASSISTED FRICTION STIR WELDING PROCESS

Abstract

This thesis describes a hybrid form of the Friction Stir Welding Process, which is a new emerging, green, and energy-efficient thermo-mechanical process for improving the material's properties through localized plastic deformation, resulting in a microstructure with ultra-fine, equidistant grains. By integrating ultrasonic vibrations into the conventional Friction Stir Welding Process, researchers would be able to obtain better mechanical properties. The contents of the thesis are as follows: Chapter 1In this chapter, the Friction stir welding process and its various classifications have been described. It has been determined how the Friction Stir Welding Process removes material from the processed parts. Later in this chapter, various hybrid FSW forms and their benefits are discussed. Chapter 2With regard to conventional Friction Stir Welding and its hybrid forms, a thorough literature review has been conducted. In addition, studies pertaining to the variable parameters affecting mechanical properties, material removal, surface finish, surface roughness scatter, residual stress, wear, and tool wear rate were reviewed. In the final section, hybrid types of Friction Stir Welding are discussed, followed by research gaps, research objectives, and research methodology. Chapter 3This chapter covers the selection of work materials, UAFSW tool materials, and experimentation specifics. The components and configurations utilized in this hybrid procedure are described in detail. This chapter also covers the welding technique of Ultrasonic Assisted Friction Stir Processing. .FEA has also been discussed for modifying workpiece surface and tool temperature process parameters. Later in this chapter, the detailed mechanical, microstructure, residual stress, and wear testing procedures are presented v Chapter 4This chapter includes optimization using Taguchi analysis along with ANOVA (Analysis of variance). Optimization was performed for output parameters such as microhardness, ultimate tensile strength and residual stress.Data analysis procedure, estimation of optimum responses and confirmation of test have also been discussed in this chapter. Chapter 5This chapter discusses the details for effect of process parameters on microhardness, tensile test and residual stress. Results of thermal analysis have been discussed. In addition, this chapter examines microstructure, SEM/EDS XRD, and wears analysis. Chapter 6 This chapter summarizes present research investigation. Important conclusions of the experimental investigation regarding optimum process parameters have been presented. Significant findings for microstructural changes, XRD and wear have been drawn from performed experimentation. This chapter also introduces scope for further research in this field.