Microstructure Development in Copper Welded by the FSW-Process

2003 ◽  
Vol 807 ◽  
Author(s):  
Therese Källgren ◽  
Rolf Sandström

ABSTRACTTo ensure safe storage of nuclear fuel waste, copper canisters are proposed as corrosion barrier. One alternative for sealing the copper canisters is Friction Stir Welding (FSW). During the joining process friction heat and mechanical deformation appear between the rotating tool and the material being welded. Liquid metal will not form, since this is a solid state welding process. Three distinct microstructural zones are developed namely the nugget, the thermo-mechanically affected zone (TMAZ) and heat-affected zone (HAZ). The nugget is in the centre of the weld, where the pin is located and where severe plastic deformation occurs that leads to recrystallisation. Surrounding the nugget, the TMAZ is only partially recrystallised, due to lower temperature increase and deformation compared to the nugget. The third zone, HAZ, surrounds the TMAZ. The initial nugget can have a classic round aluminium nugget image, when the welding conditions are cold, but the steady state nugget, is wider near the shoulder and shorter in the weld root.

2019 ◽  
Vol 48 (1) ◽  
pp. 37-46
Author(s):  
Akshansh Mishra ◽  
Devarrishi Dixit

Friction Stir Welding (FSW) is a solid state joining process which possesses a great potential to revolutionise 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 about the mechanical and microstructure properties of various aerospace alloys which are joined by FSW process.


2018 ◽  
Vol 1146 ◽  
pp. 38-43
Author(s):  
Ana Boşneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Cristian Ciucă

Friction Stir Welding, abbreviated FSW is an innovative joining process. The FSW is a solid-state welding process with a lot of advantages comparing to the traditional arc welding, such as the following: it uses a non-consumable tool, it results of good mechanical properties, it can use dissimilar materials and it have a low environmental impact. First of all, the FSW process was developed to join similar aluminum plates, and now, the technology was developed and the FSW process is used to weld large types of materials, similar or dissimilar. In this paper it is presented an experimental study and the results of it, which includes the welding of three dissimilar aluminum alloy, with different chemical and mechanical properties. This three materials are: AA2024, AA6061 and AA7075. The welding joints and the welding process were analyzed considering: process temperature, micro-hardness, macrostructure and microstructure.


2018 ◽  
Vol 38 (3) ◽  
pp. 352-359
Author(s):  
Zeng Gao ◽  
Jianguang Feng ◽  
Huanyu Yang ◽  
Jukka Pakkanen ◽  
Jitai Niu

Using friction stir welding, the electronic container box and lid made from aluminium matrix composites with reinforcement of SiC particle (15 vol% SiCp/Al-MMCs) was welded successfully with T-joint. The temperature distribution of box during the process, mechanical property and microstructure of the joint as well as gas tightness of welded box was investigated. The experimental results indicated that the satisfactory T-joint can be obtained under appropriate friction stir welding parameters. During the welding process, the bottom center, which was used to place the electronic component, reached a quite lower temperature of 100°C. That can ensure safety of components in the box. After the welding process, the microstructure in stir zone was better than in base material due to the refining and homogeneous distribution of the SiC particles. The experimental results showed that the electronic container box after friction stir welding had gas tightness. The He-leakage rate was under 10-8 Pa•m3/s.


Author(s):  
Akshansh Mishra ◽  
Adarsh Tiwari ◽  
Mayank Kumar Shukla ◽  
A. Razal Rose

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.


2007 ◽  
Vol 23 (03) ◽  
pp. 161-163
Author(s):  
Bruce Halverson ◽  
John F. Hinrichs

The US Navy's Littoral Combat Ship (LCS) represents a new direction in military capabilities and ship design. The LCS's aluminum superstructure and deckhouse reduces weight and lowers the center of gravity of the ship. Arc welding aluminum is subject to distortion requiring no value straightening activities to be used. Friction stir welding (FSW), a welding process invented in 1991 at TWI in the United Kingdom, is a solid-state welding process that has considerably less weld distortion. It results in more affordable fabrication and inspection of the butt joint weld root. Details of the FSW process development, certification, and fabrication of the LCS superstructure and deck house are described. Experience with FSW on the LCS has resulted in a number of new fabrication ideas and concepts to improve affordability of future LCS and other aluminum ship structures.


2019 ◽  
Vol 8 (4) ◽  
pp. 10975-10980

This review paper will discuss about the joining process of Aluminium 3D printing materials by using friction stir welding process. Currently, the studies on the joining of 3D printing materials by friction stir welding are very limited. Through this review, the joining materials characteristics such as weld efficiency, hardness and microstructure after friction stir welding process will be discussed to identify the behavior of weld joint materials. Understanding the friction stir welding process on 3D printing materials is importance in order to support the future advancement of 3D printing technology in terms of 3D printing part repairing activity and the secondary process such as the joining of 3D printing parts. In this paper, the fundamental concept of friction stir welding and powder bed fusion 3D printing is discussed. At the end of the review, the summary of friction stir welding process on Aluminium 3D printing materials concluded that the joining process is feasible to weld the materials with joint efficiency 83.3% and modify the base material characteristic of the 3D printing materials.


2020 ◽  
Vol 837 ◽  
pp. 69-73
Author(s):  
Ho Sung Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo

This study presents manufacturing lightweight aerospace components by solid state joining technologies. The advantages of solid state joining are due to the lack of hot cracking from solidification, since there is no liquid phase involved in joining process. This produces a high quality joint as compared to that from conventional fusion welding process. In diffusion bonding process, two different surfaces are matched together at elevated temperature under a low pressure without macroscopic plastic deformation in the interface. In friction stir welding process, the rotating shoulder of the tool generates frictional heat on the surface. As the pin rotates it forces the plastic material to mix mechanically in the vicinity of the pin and produces a heavily deformed microstructure around the pin. In this study, solid state joining processes of diffusion bonding and friction welding, are applied to manufacture several launcher components with lightweight, efficient and cost saving.


2022 ◽  
Vol 1048 ◽  
pp. 241-253
Author(s):  
Arindom Baruah ◽  
Jayaprakash Murugesan ◽  
Hemant Borkar

Friction stir spot welding process is a solid state joining process which has attracted great attention due to its ability to join low melting point light weight alloys such as aluminium and magnesium with high efficiency. In order to understand the complex thermo-mechanical joining process involved with friction stir spot welding, a numerical simulation study was done using ABAQUS finite element software. The simulation primarily aims to interpret the effect of a set of process parameters and tool geometry on the workpiece plates. Johnson-Cook damage criteria model was used to obtain the stress and strain distribution on the workpiece consisting of aluminium 6061 and magnesium AZ-31B placed in a lap configuration. Temperature distribution of the workpiece was obtained by simulating a penalty based frictional contact between the tool and the plate. The thermal results showed that the maximum temperatures attained were significantly lower than the melting points of the base materials indicating that the material mixing and joining occurred as a result of superplastic deformation process instead of melting. Change in material flow behaviour was also observed by the model as pin and shoulder geometries changed.


Author(s):  
Iraj Mantegh

Friction stir welding is a patented joining process invented in 1991 at The Welding Institute in Cambridge, UK, and further developed to the stage suitable for production. In this process, a wear resistant rotating tool is used to join sheet and plate with different materials such as aluminum, copper, lead, magnesium, zinc, and titanium. This work studies the thermal characteristics of this process and provides a modeling technique based on Neural Network that can be used for real-time control. A thermal feed-back control method is presented to control the process. Using some thermal modeling for the heat distribution during friction stir welding process, this paper displays the complexity of obtaining an accurate design for the thermal feed back control. A three-dimensional transient heat transfer model is developed here for a sequential joining process (Friction Stir Welding-FSW) applied on aluminum parts. A neural network is created based on a set of experiments to predict the spatial and temporal variations in the temperature over the weld seam for different set of input variables. The model includes the dynamic and friction behavior of the rotating spindle and the thermal behaviors of the weld components involved. The significance of this modeling approach is that it captures the movement of the spindle, simulating a sequential joining process along a continuous weld seam. The modeling results are compared with experimental data obtained by thermocouples and infrared camera, and accurately predict the trend of variations in weld temperature. A fuzzy-logic based controller is proposed to regulate the FSW process parameters to maintain the weld temperature within the margin required to ensure the weld quality. This modeling and control system can have applications in manufacturing aluminum parts in automotive and aerospace industry.


2016 ◽  
Vol 1138 ◽  
pp. 113-118
Author(s):  
Monica Iordache ◽  
Eduard Nitu ◽  
Claudiu Badulescu ◽  
Doina Iacomi ◽  
Lia Nicoleta Boţilă ◽  
...  

Friction Stir Welding (FSW) is a solid state joining process realized by the interaction between a non-consumable welding tool that rotates on the contact surfaces of the combined parts. Welding dissimilar materials aluminum and copper by FSW are of great interest because Al and Cu are two most common engineering materials widely used in many industries. This paper presents an investigation concerning the influence of the rotation of the tool on temperatures during the welding process. Also, the welding of copper and aluminum materials by FSW process was simulated using a finite element model. Three-dimensional FE model has been developed in ABAQUS/Explicit using the Coupled Eulerian Lagrangian method, the Johnson–Cook material law and the Coulomb’s Law of friction and was validated by infrared thermography method and thermocouple measurement.


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