Friction Stir Welding of 3D Industrial Parts: Joint Strength Analysis

Author(s):  
Livan Fratini ◽  
Mario Piacentini

In the recent years Friction Stir Welding (FSW) has become an important joining technique since it allows to weld light weight alloys rather difficult to be welded or even “un-weldable” with the classic fusion welding operations. In the paper the authors present the application of the FSW process to the joining of 3D complex shapes typical of the industrial environment. In particular the research was aimed to highlight the joint mechanical strength at the varying of the 3D geometry of the welding line.

2015 ◽  
Vol 809-810 ◽  
pp. 449-454 ◽  
Author(s):  
Ana Boşneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Monica Iordache ◽  
Alin Rizea

Composite materials with metallic matrix are increasingly require more than traditional materials metallic, being lighter, more reliable and with their superior properties like: rigidity, tensile strength, flexural strength, fatigue strength, modulus of elasticity, hardness, etc. Due to these advantages, above mentioned, this process has largely penetrated industrial environment. Despite these advantages, there are restrictions on their combination through traditional fusion welding methods so that was passed at the solid-state welding processes, respectively at Friction Stir Welding (FSW). Our researches presents in this brief review: some general ideas about composite materials with metallic matrix and Friction Stir Welding process, appearance and benefits, basic information about the process and composite materials welded by this process, shows the current state of the research with respect to behaviour macrostructure, microstructure, microhardness, tensile properties and defects of the welded joint between composite materials with metallic matrix.


2014 ◽  
Vol 783-786 ◽  
pp. 1759-1764
Author(s):  
S. Sanderson ◽  
M. Mahoney ◽  
Zhi Li Feng ◽  
S. Larsen ◽  
R. Steel ◽  
...  

Friction stir welding (FSW) offers both economic and technical advantages over conventional fusion welding practices for welding line-pipe. For offshore line-pipe construction, the economic savings has been shown to be considerable, approaching a calculated 25%. Offshore pipe is relatively small diameter but heavy wall compared to onshore pipe. One concern is the ability to achieve consistent full weld penetration in an on-site offshore FSW operation, e.g., on a lay-barge. Further, depending on the size and morphology of the unwelded zone, lack of penetration at the weld root can be difficult if not impossible to detect by conventional NDE methods. Thus, an approach to assure consistent full penetration via process control is required for offshore line-pipe construction using FSW. For offshore construction, an internal structural mandrel can be used offering the opportunity to use a sacrificial anvil FSW approach. With this approach, a small volume of sacrificial material can be inserted into the structural anvil. The FSW tool penetrates into the sacrificial anvil, beyond the inner diameter of the pipe wall, thus assuring full penetration. The sacrificial material is subsequently removed from the pipe inner wall. In the work presented herein, FSW studies were completed on both 6 mm and 12 mm wall thickness line-pipe. Post-FSW evaluations including radiography, root-bend tests, and metallography demonstrated the merits of the sacrificial anvil approach to achieve consistent full penetration.


Author(s):  
Sharda Pratap Shrivas ◽  
G.K. Agrawal ◽  
Shubhrata Nagpal ◽  
Amit Kumar Vishvakarma ◽  
Ashish Kumar Khandelwal

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>


2014 ◽  
Vol 984-985 ◽  
pp. 586-591 ◽  
Author(s):  
R. Ashok Kumar ◽  
M.R. Thansekhar

— For fabricating light weight structures, it requires high strength-to weight ratio. AA6061 aluminium alloy is widely used in the fabrication of light weight structures. A356 aluminium alloy has wide spread application in aerospace industries. Friction stir welding is solid state joining process which is conducting for joining similar and dissimilar materials. The friction stir welding parameters play an important role for deciding the strength of welded joints. In this investigation, A356 and AA6061 alloys were friction stir welded by varying triangular, square, hexagonal pin profiles of tool keeping the remaining parameters same and AA6061 alloys were friction stir welded by varying tool shoulder diameter as 12mm,15mm,18mm without changing other parameters. Tensile properties of each joint have been analyzed microscopically. From the experimental results, it is observed that hexagonal pin profiled tool and 15mm shoulder diameter tool provides higher tensile properties when compared to other tools.


Author(s):  
Lewis N. Payton

Friction Stir Welding (FSW) is a solid-state joining process invented by The Welding Institute (TWI, United Kingdom) in 1991 in partnership with the National Aeronautics Space Agency. The process is emerging as one of the preferred alternative methods to permanently join materials that are difficult to join with traditional fusion methods (e.g., MIG, TIG, etc.). The welding of various copper alloys to various aluminum alloys is of great interest to the nuclear industry and the electrical distribution industry. The very different melting points of these two alloys preclude traditional fusion welding. Since the pin tool is simultaneously rotating and traversing through the work piece, flow around the tool is asymmetrical. This has led to designating one side of the tool as advancing and the opposite side as retreating. On the advancing side of the weld, the tool has a tangential velocity in the same direction as the weld is being created. The retreating side of the weld tool is the opposite. It can be can expected that asymmetric heating and deformation will occur in the weld due to this advancing/retreating nature of the FSW pin tool. Although previous studies have been performed that have observed this asymmetric behavior in both similar and dissimilar materials, the resulting welds have been of a poor quality. Large statistical experiments were conducted locally to study the effects of tool geometry, process parameters, and material composition have upon the friction stir butt welding of aluminum alloy 6061-T6 to copper alloy 11000 using a modern conventional 3-axis CNC vertical mill. The research seeks to determine (1) which direction a dissimilar metal friction stir weld between aluminum and copper should be executed, (2) the optimal shoulder diameter to be used when friction stir welding aluminum and copper on a CNC mill, and (3) the addition of a third material to act as an aide. The extensive statistical interactions between these parameters is also documented. A weld schedule was developed that resulted in an ultimate tensile strength (UTS) surpassing (greater than 90% of the weaker, more ductile copper alloy UTS strength) what has been documented in the current literature despite the machine limitations of the CNC vertical mill. Proper optimization of the welding schedule developed may approach 100 percent of the basic copper 11000 properties across the welded zone into the aluminum 6061-T6 alloy.


2021 ◽  
Vol 63 (9) ◽  
pp. 829-835
Author(s):  
Sare Çelik ◽  
Fatmagül Tolun

Abstract AA5754Al alloy is widely used in industry. However, as in the case of all Al alloys, the 5xxx series Al alloys cannot be easily joined through fusion welding techniques. To address this problem, in this study, the effect of double-sided friction stir welding at various tool rotational speeds (450, 710, and 900 rpm), feeding rates (40, 50, and 80 mm × min-1), and tool tilt angles (0°, 1°, 2°) on the welding parameters and mechanical and microstructural characteristics of AA5754 Al alloy was determined. Tensile strength tests and microhardness tests were performed to examine the mechanical properties of the welded specimens. The microstructures of the welded zone were examined by obtaining optical microscopy and scanning electron microscopy images. The tensile test results indicated that the specimens exhibited the highest welding performance of 95.17 % at a tool rotational speed, feed rate, and tool tilt angle of 450 rpm, 50 mm × min-1 and 1°, respectively.


2022 ◽  
pp. 206-214
Author(s):  
Radha R. ◽  
Sreekanth D. ◽  
Tushar Bohra ◽  
Surya Bhan Pratap Singh

Friction stir welding (FSW) is considered to be the most significant development in solid state metal joining processes. This joining technique is energy efficient, environmentally friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. The project aims to join Aluminum 6063 alloy plates by FSW and emphasize the (1) mechanisms responsible for the formation of welds without any defects, microstructural refinement, and (2) effects of FSW parameters on resultant microstructure, mechanical, and corrosion properties.


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