scholarly journals Experimental Analysis of FSW Process Forces

2020 ◽  
Vol 44 (2) ◽  
pp. 51-56
Author(s):  
Tadeusz Balawender ◽  
Piotr Myśliwiec

AbstractThis paper presents the results of research work on linear friction stir welding (FSW) of magnesium AZ31 and aluminum 2024 alloys. During the FSW process, forces exerted by a tool on joined materials were measured. The measurements of forces were taken in three directions, vertical (Z axis) and horizontal (X and Y axes) directions, using high-sensitive piezoelectric dynamometer. The force analysis was done for three stages of welding process: plunging, dwelling, and welding. Conclusions regarding the force reaction of materials to be welded were formulated. It was found that the first two stages of the process, plunging and dwelling, are very important for the correct welding. In the plunging stage, a tool exerts the greatest forces and unit pressures (at the Z direction) on joined materials; during the dwelling stage, thermal conditions of the process are established. The welding stage was divided into two substages: the initial unstable and the subsequent long-term stabilized one.

2021 ◽  
Author(s):  
Bazani Shaik ◽  
Gosala Harinath Gowd ◽  
Bandaru Durga Prasad

Today is an era of metals including Aluminum alloys owing to a fundamental paradigm shift in research objectives. In addition to superior performance and lightweight criteria that are used to define the innovations of yore, scientists today are compelled to take into consideration the environment-friendliness of the new and novel materials being developed due to the concerns of maintaining a sustainable and safe existence. The solid-state Friction stir welding process has immense potential in the areas of automobiles, aerospace and construction industries due to its overwhelming advantages over the conventional fusion welding process of aluminum alloys. The thesis presents an experimental investigation of friction stir welding of dissimilar aluminum alloys AA7075T651 and AA6082T651. Mathematical modeling equations are developed to predict the tensile strength, impact strength, elongation, and micro-hardness of the dissimilar FSW joints AA7075T651 and AA6082T651. The process parameters are optimized for maximum tensile strength and hardness values. Post weld heat treatment is conducted and the metallurgical properties of the FS welded AA7075T651 and AA6082T651 are presented for different combinations of tool rotational speeds. Aluminum and its alloys are widely used in nonferrous alloys for many industrial applications. Aluminum exhibits a combination of an excellent mechanical strength with lightweight and thus it is steadily replacing steel in industrial applications where the strength to weight ratio plays a significant role. In conventional welding, the joining of aluminum is mainly associated with a high coefficient of thermal expansion, solidification shrinkage and dissolution of harmful gases in the molten metal during welding. The weld joints are also associated with segregation of secondary alloys and porosities which are detrimental to the joint qualities. Friction Stir Welding (FSW) and Friction Welding (FW) are the most popular emerging solid welding techniques in aircraft and shipbuilding industries. FSW is mainly used for the joining of metal plates and FW is mainly used for the joining of rods. Both techniques are suitable for high strength material having less weight. These techniques are environmentally friendly and easy to execute. Hence, the study of these techniques can contribute much to the field of green technology. This research work is dealt with the experimental and numerical investigations on FSW and FW of aluminum alloys.


Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).


2021 ◽  
Author(s):  
Davide Campanella ◽  
Gianluca Buffa ◽  
Livan Fratini

In recent years, the development of innovative joining methods has increased significantly due to the demands of several industries, such as the naval one, for lightweight structures. In fact, the safeguarding of the sea takes place through the reduction of climate-altering gas emissions, which is induced by energy savings. The latter can be achieved by the adoption of innovative technological solutions inherent to both the manufacturing processes and the increase in the use of light alloys. These solutions can reduce the environmental impact of vessels both in refitting operations and in new buildings. Although its potential in producing effective joints of different materials, the Friction Stir Welding process is still poorly used in the naval field due to difficulties in welding dissimilar joints of thick plates. In this paper, Friction Stir Welding was used to produce joints, in lap configuration, out of two very different, yet widely used in the naval sector, materials. This research work focuses on the engineering of the process, in terms of identification of welding parameters aimed at welding AA5083 H321 aluminum alloy and naval steel grade DH 36 plates with a thickness of 6mm. The results obtained indicate that sound joints can be obtained with a reasonably wide process parameters window when the aluminum plate is placed on top of the steel one.


2010 ◽  
Vol 89-91 ◽  
pp. 697-702
Author(s):  
Sandra Zimmer ◽  
Laurent Langlois ◽  
Julien Laye ◽  
Jean Claude Goussain ◽  
Patrick Martin ◽  
...  

This paper presents an experimental methodology to determine a Friction Stir Welding (FSW) means of production based on the experimental study of the tool / material mechanical interactions generated during the plunging and welding stages. These two stages have been identified as being characteristic for the qualification of a FSW equipment. This paper presents the experimental results of the parametric study done on the plunging and welding phases. Ranges of forces and torques diagrams were established according to the processing parameters, in order to qualify a means of production and select the process parameters allowing the operation on the available FSW equipment.


2017 ◽  
Vol 61 (4) ◽  
pp. 296 ◽  
Author(s):  
Kayode Oyedemi ◽  
Patrick McGrath ◽  
Hannalie Lombard ◽  
Balázs Varbai

This paper presents research work conducted to experimentally establish the process response of two diverse shaped tool-pin profiles for friction stir welding (FSW) AA6082-T6 aluminium. The dwell time was optimised by plunging each tool-pin into a plate sample until the spindle torque stabilised thus ensuring sufficient plasticised material in contact with tool shoulder and the tool-pins. The welds were conducted by employing the optimised dwell time, which in turn revealed a minimised process response time and distance to reach weld stability with respect to (1) the force exerted on the tool-pin in the welding direction, Fx , and (2) the spindle torque, T, during the welding process. Both Fx and T stabilised well within the set (pre-determined) ramp-up distance of 20 mm, indicating that the effective (useful) weld length is maximised. The macrographs also revealed good dynamic material flow within the nugget zone regions and more evident in the nugget zone of the flared tool.


2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.


Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.


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