Techshore Welding Technology Centre / NDT | Palakkad | Mannar

Techshore Welding Technology Centre is an initiative of the leading professional & reputed training brand of Techshore Inspection Services, which is having training centres all over Kerala. Techshore offers courses in Welding from early 2015 and successful in providing placements for all those candidates in reputed companies with attractive salary packages and perks.

Techshore provides, Friction Stir Welding (FSW), It is a solid-state welding procedure employ for welding similar and dissimilar materials. The procedure is widely employed because it produces sound welds and does not have universal problems such as solidification and liquefaction cracking associated with the fusion welding methods. The FSW of Aluminum and its alloys have been commercialized, and recent attention is focused on joining dissimilar materials. However, in order to commercialize the procedure, research studies are essential to characterize and establish procedure windows. In particular, FSW has inspired investigators to attempt joining dissimilar materials such as aluminum to copper which vary in properties and sound welds with none or limited intermetallic compounds has been produced. In this paper, we review the current research state of FSW between aluminum and copper with a center on the resulting weld microstructure, mechanical trying and the tools employed to produce the welds and also an insight into future research in this field of study.

INTRODUCTION

Researchers have been focused on developing fast and eco-friendly procedures in manufacturing and this include Friction Stir Welding and Procedure. Friction Stir Welding (FSW) is a solid-state joining method invented and patented by The Welding Institute (TWI) in 1991 for butt and lap welding of ferrous and non–ferrous metals and plastics. FSW is a continuous procedure that involves plunging a portion of a particularly shaped rotating tool between the butting faces of the joint. The relative motion between the tool and the substrate generates frictional warm that creates a plasticized region about the immersed portion of the tool. Friction stir welding procedure uses a non-consumable rotating tool consisting of a pin extending below a shoulder that is required into the adjacent mating edges of the workpiece The heat input, the forging action and the stirring action of the tool induces a plastic flow in the substance, forming a solid-state weld. 

It was realized in the development of the FSW procedure that the tool design is critical in producing sound welds. A basic and conventional design for an FSW tool which consists of a threaded pin and a concave shoulder. FSW tools follow the same vital trends in terms of their shape and geometries. They are generally consisting of three generic features including a shoulder, a probe also known as a pin and external features on the probe.

FSW joints frequently consist of varying regions as following the terminologies employed by Thread gill which include the unaffected material or parent metal, the Heat-Affected Zone, the Thermo mechanically Affected Zone and the weld nugget.

An unaffected material B, heat affected zone C, thermomechanically affected zone D, weld nugget. The Unaffected material or parent material is the material distant from the welds that have not been deformed. The Heat Affected The zone is the region which lies closer to the weld centre; the material has practiced a thermal cycle that has customized the microstructure and the mechanical properties. Though no plastic deformation occurs in this area. The Thermo Mechanically Affected Zone (TMAZ) is the area in which the FSW tool has plastically deformed the material, and the heat from the method has also exerted some influence on the material. In the case of aluminum, it is possible to get significant plastic strain lacking recrystallization in this region and there is usually a distinct boundary between the recrystallized zone (weld nugget) and the deformed zone of the TMAZ and the Weld nugget is the fully recrystallized area, occasionally called the Stir Zone (SZ) or Stir Nugget (SN), it refers to the zone previously occupied by the tool pin. Prior to the development of FSW, conventional fusion welding procedures were employed to join similar and dissimilar materials. Friction stir welding of dissimilar materials ruins not completely researched. Friction stir welding of dissimilar materials such as aluminum and copper, in particular, require to be fully understood due to their variant melting temperatures. The high chemical affinity of equally base materials promotes the formation of brittle intermetallic Al/Cu phases, which requires extensive research. 

Additionally, aluminum and copper are not easy to weld with conventional welding procedures due to their high reflectivity and thermal conductivity. Brittle intermetallic phases expand in the joint zone since copper and aluminum are not very soluble in the solid state. These intermetallic phases lower the toughness of the weld and guide to cracks during and after the welding. Moreover, aluminum to copper welding is increasingly engaged in some realistic applications such as heat transfer equipment, electrical and electronics industries, aesthetical applications, etc. In addition, aluminum alloys are extensively employed to produce aerospace components with high specific strength. However, when traditional welding procedures are applied to these aluminum alloys, they often involve disadvantages that have sometimes discouraged the use of welded components. Many investigators have published reviews on friction stir welding and focusing on the tools employed, Friction stir procedure, dissimilar alloys and on aluminum alloys. To the best of our knowledge, no evaluation focusing on friction stir welding of aluminum to copper has been published. As a result, this paper significantly reviewed the accessible published literature by focusing on the latest work done on friction stir welding of aluminum-copper alloys. The rest of the paper is for employed on the resulting microstructural development, the mechanical properties categorization and the tools engaged to produce the welds between aluminum and copper.

CONCLUSIONS AND FUTURE RESEARCH

FSW procedure is an eco-friendly solid-state joining method compared to the conventional welding techniques. The joining of aluminum to copper using FSW has been reviewed to open a research window to investigators in order to expand the method to other aluminum and copper alloys with the aim of achieving optimized parameters thereby leading to the commercialization of joints among these materials. Investigation on friction stir welding between aluminum and copper has not yet been thoroughly researched. Greatly the work has been focused employed on welds characterizations and study of the material flow. There is still, a strong requirement in developing the industrial applications of FSW between aluminum and copper in the manufacturing sector for the improvement of the industries. 

Thus, the use of the FSW method to join aluminum and copper alloys and material shapes is of importance in the development of their industrial applications. In summary, the review of the friction stir welding of dissimilar materials focusing on aluminum and copper has been successfully conducted. This will provide a comprehensive insight for the current and also supply the current state of research on FSW between aluminum and copper in order to fill the gaps with new research approaches and ideas. In addition, new studies on FSW between aluminum and copper with respect to the procedure optimization and collection of cost-effective FSW tools to produce sound welds still needs to be developed.

Techshore - Career Objective of Friction Stir Welding

The FSW process parameters such as tool rotational speed, tool traverse speed, tilt angle, and tool offset influence the mechanical properties of the friction stir welded joints significantly.

Techshore – Scope of Friction Stir Welding

Friction stir welding or FSW is a means of welding that heats up the metal to be welded using the friction of a blunt, rotating tool, then pushes together the heat-softened material (usually through the geometry of the rotating tool).

One key advantage of FSW is that the metal never melts.  That means it is possible to attach metals through FSW at crazy angles, without worrying about dripping gobs of molten metal.  This is possible because FSW controls the heat input to the workpiece much more precisely than heating them with a burning gas (like oxy-acetylene welding) or an electric arc (MIG or TIG welding).