Friction Stir Welding Lap Joint Resistance Optimization Through Gradient Techniques

2007 ◽  
Vol 129 (6) ◽  
pp. 985-990 ◽  
Author(s):  
L. Fratini ◽  
V. Corona

In recent years, scientific interest on friction stir welding (FSW) has grown more and more since such a joining technique allows one to weld lightweight alloys that are rather difficult to weld or even “unweldable” with the classic fusion welding operations. Furthermore, few industrial applications of the process are already known in different manufacturing fields. In this paper, the optimization problem of a FSW lap joint for automotive applications is investigated, taking into account process parameters such as the tool rotating speed and the tool feed rate; a numerical gradient technique is applied for the optimization procedure reducing the number of experimental tests to be developed.

2016 ◽  
Vol 835 ◽  
pp. 191-196 ◽  
Author(s):  
Kookil No ◽  
Ye Rim Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo ◽  
Ho Sung Lee

Friction stir welding is a widely used welding process for aluminum alloys because it avoids many of the problems of conventional fusion welding. This process is beneficial especially for lithium containing aluminum alloys in which the reactive property of element Li causes porosity and hot cracking during melting and solidification. In friction stir welding process, each region undergoes different thermo-mechanical cycles and produces a non-homogeneous microstructure. In the present study, the mechanical properties and microstructure of a 2195-T8 aluminum alloy joined with friction stir welding were investigated. The change in microstructure across the welded joint was found to correspond to microhardness measurement. The microstructure was characterized by the presence of severely deformed grains and fine recrystallized grains depending on the region. Tensile tests shows the optimum condition was obtained at the tool rotating speed of 600rpm and the traveling speed range from 180 to 300mm/min.


Author(s):  
Rasha M . Hussien

Friction stir welding (FSW) has many advantages when compared with another fusion welding. The experimental analysis and optimization of friction stir welding (FSW) were done to obtain desired mechanical properties of dissimilar aluminum welded plates (2024T3 and 7075T6). The friction stir welding process was done on aluminum plates (2024T3 and 7075T6) for different three rotating speeds (710, 1120 and 1800), three welding speeds (25, 50 and 77), three different steel tools (Square, cylindrical and Hexagonal) and 2° title angle. The different tests of welding were done according to the orthogonal matrix of experimental design analysis, then a tensile test was done to calculate the ultimate stress to get the welding efficiency. The optimum welding environment led to the maximum efficiency was obtained by these methods (Taguchi, Particle Swarm Optimization and new modified Particle Swarm Optimization). Particle swarm optimization (and its new modification) used an artificial neural network to find the relation between the input and output parameters. The results showed that when the rotating speed is increased and welding speed is decreased (but this conclusion depends on tool shape) the welding efficiency is increased. The present study showed that the modified PSO is the best method to find the optimum welding environment as compared with experimental results


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.


2013 ◽  
Vol 376 ◽  
pp. 42-48 ◽  
Author(s):  
S.N. Pandya ◽  
J.V. Menghani

Many engineering applications in aerospace and automotive field require joining of dissimilar 5xxx to 6xxx Al alloys. Dissimilar Al alloy joints are used for industrial applications due to technical & economic reasons. However, due to different metallurgical behaviour & mechanical properties, joining of dissimilar Al alloys presents a number of challenges. Due to high temperature generation most of the fusion welding techniques are not suitable. In addition, other pressure welding techniques such as – Ultrasonic welding, Roll bonding, Diffusion bonding and Friction welding have some limitation. Hence, friction stir welding (FSW) can be considered to be the most suitable method to join dissimilar Al alloys due to solid-state nature of the process. Since invention, friction stir welding has been a matter of research and investigation for years. In its history of two decades, Friction Stir welding was investigated for joining dissimilar Al alloys during the last decade. Most of studies demonstrated that good quality joints between dissimilar Al alloys can be produced by the Friction Stir Welding (FSW) process. The present study is a chronological & critical review of recent studies on joining of dissimilar 5xxx to 6xxx Al alloys by friction stir welding.


2021 ◽  
Vol 880 ◽  
pp. 57-62
Author(s):  
Normariah Che Maideen ◽  
Salina Budin ◽  
Koay Mei Hyie ◽  
Nor Azirah Mohd Fohimi

Stirring tool is one of the important factor that contribute to the successful of Friction Stir Welding (FSW). Role of tool, is to heat the welding zone and stir the material along the process. Many studies have been conducted by other researchers to improve the performance of stirring tool. Similar to this work, it is aimed to investigate and analyze the effect of stirring tool surface condition on wear characteristics in friction stir welding process. Four tools have been fabricated with pre-determined surface condition. Tool 1: H13 without heat treatment and without coating. Tool 2: H13 with heat treatment only. Tool 3: H13 with TiCN coating only and Tool 4: H13 with heat treatment and with TiCN coating. Friction stir welding was performed to test and verify the performance of fabricated tools. Process parameter used are 1270 RPM for rotating speed while 218 mm/min for welding speed. From the result, Tool 4 performed better in terms of physical wear as well as wear rate.


2021 ◽  
Vol 2021 (6) ◽  
pp. 5340-5345
Author(s):  
WIDIA SETIAWAN ◽  
◽  
BERNADO PASARIBU ◽  
MUHAMMAD BADARUDIN THOHA ◽  
GUSTI KETUT PUDJA ◽  
...  

The lap joint will be used on aluminum 6061 and 10 mm thick brass with the Friction Stir Welding method. The probe used is EMS 45 steel with variations in pin lengths of 11 mm, 11.5 mm and 12 mm. The results of this study are in length 11.5 mm with the highest Vickers hardness value of 104.26 VHn compared to 11 mm and 12 mm pin length is 98.93 VHn and 70.43 VHn. The results of shear stress are 67.32 MPa at 12 mm pin length, higher than the 11 mm and 11.5 mm pin lengths of 40.2 MPa and 42.14 MPa.


2021 ◽  
Vol 50 (9) ◽  
pp. 2743-2754
Author(s):  
Ashish Jacob ◽  
Sachin Maheshwari ◽  
Arshad Noor Siddiquee ◽  
Abdulrahman Al-Ahmari ◽  
Mustufa Haider Abidi ◽  
...  

Certain age hardenable alloys such as AA7475 cannot be joined with perfection using fusion welding techniques. This requires non-conventional welding technique such as friction stir welding process to join these ‘difficult to weld’ alloys. In this study, three different cooling conditions i.e. cryogenic, sub-zero, and zero-degree Celsius temperature conditions have been analyzed to understand its impact on the welding process. In-process cooling was found to behave effectively and also enhanced the mechanical properties of the welded joints. A stable microstructure was clearly seen in the images observed under the metallurgical microscope. The weld efficiencies were found to be good in each of the samples which are indicative of a strong metallic joint. The effective cooling conditions employed had an overall positive impact on the joint.


Author(s):  
Santosh Vanama

<p>The paper propose modelling and fabrication of friction stir welding end-effector for ABB IRB1410 robot. A dynamically developing version of pressure welding processes, join material without reaching the fusion temperature called friction stir welding. As friction stir welding occurs in solid state, no solidification structures are created thereby eliminating the brittle and eutectic phase’s common to fusion welding of high strength aluminium alloys. In this paper, Friction stir welding is applied to aluminum sheets of 2 mm thickness. A prototype setup is developed to monitor the evolution of main forces and tool temperature during the operation. Pressure of a gripper plays a major role for tool rotation and developing torque.  Fabrication of the tool has done. Force calculations are done by placing the sensors on the outer surface of gripper. Methods of evaluating weld quality are surveyed as well.</p>


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