Micro Friction Stir Welding Process: State of the Art

 Micro friction stir welding (µFSW) process is mainly adapted from the Friction Stir Welding Process. This process is mainly used for joining dissimilar materials. Micro friction stir welding (µFSW) find its applications in thin walled structures, electrical, electronic and micro-mechanical assemblies. The significant challenges are faced when we downscale to achieve µFSW. This paper addresses the current state of the understanding and development of Micro friction stir welding. This paper further outlines the results achieved after Micro friction stir processing of Aluminium alloys, Copper alloys and Zinc alloys. 

Analysis of Tools used in Friction Stir Welding process

 A relatively new joining process, friction stir welding (FSW) produces no fumes; uses no filler material; and can join aluminium alloys, copper, magnesium, zinc, steels, and titanium. FSW sometimes produces a weld that is stronger than the base material. The tool geometry plays a critical role in material flow and governs the transverse rate at which FSW can be conducted. The tool serves three primary functions, i.e., (a) heating of the work piece, (b) movement of material to produce the joint, and (c) containment of the hot metal beneath the tool shoulder. Heating is created within the work piece by friction between both the rotating tool pin and shoulder and by severe plastic deformation of the work. 

Cryogenic heat treatment on FSWed joints.

 If we talk about the thermal processing of metals, it is nothing new. Heat treatment of metals dates back to thousands of years. Metal characteristics have been altered by using various heat treatment processes. But the treating the metals at the cold temperature especially at very cold temperature in the cryogenic range is relatively new and has not been accepted fully in the manufacturing industries. This paper focuses on the change of mechanical properties of Friction Stir Welded joints after cryogenic treatment process. 

Friction Stir Welding of Aerospace Alloys

 Friction Stir Welding (FSW) is a solid-state joining process which possesses a great potential to revolutionize the aerospace industries. Distinctive materials are selected as aerospace alloys to withstand higher temperature and loads. Sometimes these alloys are difficult to join by a conventional welding process but they are easily welded by FSW process. The FSW process in aerospace applications can be used for aviation for fuel tanks, repair of faulty welds, cryogenic fuel tanks for space vehicles. Eclipse Aviation, for example, has reported dramatic production cost reductions with FSW when compared to other joining technologies. This paper will discuss the mechanical and microstructure properties of various aerospace alloys which are joined by FSW process. 

Analysis of FSWed Magnesium alloy joints.

Friction Stir Welding is used already in routine, as well as critical applications, for the joining of structural components made of aluminium and its alloys. Indeed, it has been convincingly demonstrated that the process results in strong and ductile joints, sometimes in systems which have proved difficult using conventional welding techniques. The aim of this study was to evaluate microstructures, tensile strength and Hardness of welded specimen of Magnesium-Magnesium (Mg/Mg) similar joints and Magnesium-Aluminium (Mg/Al) dissimilar joints. 

Application of Neural Network Techniques in FSW Process

Artificial Neural Network (ANN) is a brain modelling technique by providing a new approach to computing. It introduces a less technical way to develop machine solutions. This research paper discusses the use of Artificial Neural Network (ANN) concept in Friction Stir Welding research, for example it is used in the investigation of tool parameters, for the evaluation of feedback forces which is provided by Friction Stir Welding process. Previous research also shows that ANN finds application in developing the correlation between the Friction Stir Welding parameters of the light alloy plates and mechanical properties. This method was also used for predicting average grain size in Friction Stir Welding processes.