Deepika Harwani Int. Journal of Engineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 12( Part 1), December 2014, pp.64-70 www.ijera.com 64 | Page A Review: Welding Of Dissimilar Metal Alloys by Laser Beam Welding & Friction Stir Welding Techniques Ms. Deepika Harwani*, Mr. Kapil Banker** *PG Student, Department of Mechanical, SVBIT, Gujarat Technological University, India **Assistant Professor, Department of Mechanical, SVBIT, Gujarat Technological University, India ABSTRACT Welding of dissimilar metals has attracted attention of the researchers worldwide, owing to its many advantages and challenges. There is no denial in the fact that dissimilar welded joints offer more flexibility in the design and production of the commercial and industrial components. Many welding techniques have been analyzed to join dissimilar metal combinations. The objective of this paper is to review two such techniques – Laser welding and Friction stir welding. Laser beam welding, a high power density and low energy-input process, employs a laser beam to produce welds of dissimilar materials. Friction stir welding, a solid-state joining process, is also successfully used in dissimilar welding applications like aerospace and ship building industries. This paper summarizes the trends and advances of these two welding processes in the field of dissimilar welding. Future aspects of the study are also discussed. Keywords – dissimilar, friction stir welding, laser welding, microstructure, tensile test I. INTRODUCTION Engineers today are facing the challenge to join dissimilar materials as they are seeking to create new structures or machine parts in various industries. Joining of dissimilar materials is very attractive for many applications as we can use the more costly one only where necessary. In fact, dissimilar joining could be frequently faced in many scenarios including automotive, aerospace, electronics and shipbuilding industries. [1] The demand for producing joints of dissimilar materials which can provide appropriate mechanical properties and good cost reduction is continuously increasing due to their advantages. [2] Problems including porosity formation, solidification cracking, and chemical reaction may arise during fusion welding of dissimilar materials although sound welds may be obtained in some limited cases with special attentions to the joint design and preparation, process parameters and filler metals.[1] The problems arising in realizing welded joints from sheets of different materials that are difficult to obtain by employing commonly used technologies, have lead to a widespread use of new techniques of welding. [2] Two such techniques which are being adopted for joining of unlike metal pairs are Laser Beam Welding (LBW) and Friction Stir Welding (FSW). II. OVERVIEW OF THE PROCESSES This section gives an overview about the two aforementioned welding processes. 2.1 Friction Stir Welding Process Friction stir welding (FSW) is a solid state welding technique used for joining successfully aluminum alloys. A friction stir butt weld is produced by plunging a rotating tool into the facing surfaces of two plates. The tool consists of a shoulder and a profiled pin emerging from it. As the rotating pin moves along the weld line, the material is heated up by the friction generated by the shoulder and stirred by the rotating pin in a process similar to an extrusion. [3] The schematic of its working is shown in the Fig. 1. Due to the absence of parent metal melting, the new FSW process is observed to offer several advantages over fusion welding. The benefits that stand out most are welding of difficult to weld alloys, better retention of baseline material properties, fewer weld defects, low residual stresses, and better dimensional stability of the welded structure. Above all, FSW is an environmentally cleaner process, due to the absence of a need for the various gases that normally accompany fusion welding. [4] FSW process produces no smoke, fumes, arc glare and it is an eco-friendly process. Further, no consumable filler material or profiled edge preparation is normally necessary. [4] RESEARCH ARTICLE OPEN ACCESS