Friction Based Solid State Welding Processes

2012 ◽  
Vol 504-506 ◽  
pp. 3-14 ◽  
Author(s):  
Livan Fratini ◽  
Gianluca Buffa ◽  
Dario la Spisa
Keyword(s):  
Solid State ◽  
Material Flow ◽  
Research Issues ◽  
Friction Stir ◽  
Linear Friction ◽  
Process Mechanics ◽  
Frictional Forces ◽  
Industrial Use ◽  
Mechanical Performances ◽  
Welding Processes

In the last decade the industrial use of solid state welding processes based on frictional forces work decaying into heat is continuously increasing due to their strong advantages with respect to traditional fusion techniques. Several advances have been proposed by the scientific community regarding process mechanics, material flow and also the computer aided engineering of the operation with the aim to maximize the mechanical performances of the welded joints. In the paper Friction Stir Welding (FSW) and Linear Friction Welding (LFW) operations are considered and a review of the most relevant research issues and results is provided.

Numerical Study of the Tool Rake Angle Effect on the Material Flow in Friction Stir Welding Process

2007 ◽  
Author(s):  
Hosein Atharifar ◽  
Radovan Kovacevic
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Numerical Study ◽  
Welding Process ◽  
Rake Angle ◽  
Heat Transfer Analysis ◽  
Tool Geometry ◽  
Friction Stir ◽  
Tool Pin ◽  
Welding Processes

Minimizing consumed energy in friction stir welding (FSW) is one of the prominent considerations in the process development. Modifications of the FSW tool geometry might be categorized as the initial attempt to achieve a minimum FSW effort. Advanced tool pin and shoulder features as well as a low-conductive backing plate, high-conductive FSW tools equipped with cooling fins, and single or multi-step welding processes are all carried out to achieve a flawless weld with reduced welding effort. The outcomes of these attempts are considerable, primarily when the tool pin traditional designs are replaced with threaded, Trifiute or Trivex geometries. Nevertheless, the problem remains as to how an inclined tool affects the material flow characteristics and the loads applied to the tool. It is experimentally proven that a positive rake angle facilitates the traverse motion of the FSW tool; however, few computational evidences were provided. In this study, numerical material flow and heat transfer analysis are carried out for the presumed tool rake angle ranging from −4° to 4°. Afterwards, the effects of the tool rake angle to the dynamic pressure distribution, strain-rates, and velocity profiles are numerically computed. Furthermore, coefficients of drag, lift, and side force and moment applied to the tool from the visco-plastic material region are computed for each of the tool rake angles. Eventually, this paper confirms that the rake angle dramatically affects the magnitude of the loads applied to the FSW tool, and the developed advanced numerical model might be used to find optimum tool rake angle for other aluminum alloys.

Solid State Welding Process for Aerospace Components

2015 ◽  
Vol 1119 ◽  
pp. 597-600
Author(s):  
Hyun Ho Jung ◽  
Ye Rim Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo ◽  
Kyung Ju Min ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Solid State ◽  
Structural Integrity ◽  
Welding Process ◽  
Diffusion Welding ◽  
Intimate Contact ◽  
Friction Stir ◽  
Base Materials ◽  
Welding Processes ◽  
And Diffusion

Since solid state welded joint is formed from an intimate contact between two metals at temperatures below the melting point of the base materials, the structural integrity of welding depends on time, temperature, and pressure. This paper provides some of examples of friction stir welding and diffusion welding process for aerospace components. Friction stir welding process of AA2195 was developed in order to study possible application for a large fuel tank. Massive diffusion welding of multiple titanium sheets was performed and successful results were obtained. Diffusion welding of dissimilar metals of copper and stainless steel was necessary to manufacture a scaled combustion chamber. Diffusion welding of copper and steel was performed and it is shown that the optimum condition of diffusion welding is 7MPa at 890°C, for one hour. It is shown that solid state welding processes can be successfully applied to fabricate lightweight aerospace parts.

scholarly journals Friction Stir Welding and Friction Spot Stir Welding Processes of Polymers—State of the Art

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2291 ◽  
Author(s):  
Francesco Lambiase ◽  
Hamed Aghajani Derazkola ◽  
Abdolreza Simchi
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
State Of The Art ◽  
Online Measurement ◽  
Future Perspectives ◽  
Influence Of Process Parameters ◽  
New Developments ◽  
Friction Stir ◽  
Academic Researchers ◽  
Welding Processes

In the last decade, the friction stir welding of polymers has been increasingly investigated by the means of more and more sophisticated approaches. Since the early studies, which were aimed at proving the feasibility of the process for polymers and identifying suitable processing windows, great improvements have been achieved. This owes to the increasing care of academic researchers and industrial demands. These improvements have their roots in the promising results from pioneer studies; however, they are also the fruits of the adoption of more comprehensive approaches and the multidisciplinary analyses of results. The introduction of instrumented machines has enabled the online measurement of processing loads and temperature, and critical understanding of the principal aspects affecting the material flow and welds quality. Such improvements are also clearly demonstrated by the increase of the strength of recent joints (up to 99% of joining efficiency) as compared to those reached in early researches (almost 47%). This article provides a comprehensive review of the recent progresses on the process fundamentals, quality assessment and the influence of process parameters on the mechanical behavior. In addition, emphasis is given to new developments and future perspectives.

A Non-Conventional Technique for Evaluating Welded Joints Based on the Electrical Conductivity

2014 ◽  
Vol 611-612 ◽  
pp. 671-676 ◽  
Author(s):  
Telmo G. Santos ◽  
Gonçalo Sorger ◽  
Pedro Vilaça ◽  
R.M. Miranda
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Welded Joints ◽  
Conventional Technique ◽  
Carbon Steels ◽  
Fusion Welding ◽  
Friction Stir ◽  
Wide Range ◽  
Welding Processes ◽  
Non Destructive

Recent studies showed that electrical conductivity is a valuable technique to identify the different zones of solid-state welded joints with a good correlation with the microstructure and hardness. This is a relevant result since this technique is expedite and, in some cases, non destructive. The concept was applied to other welding processes as the ones involving fusion and to a wide range of materials. For this, a comprehensive study was performed using friction stir welding, tungsten inert gas (TIG) and gas metal arc (MAG) welding processes in either bead on plate or butt joints in: carbon steel, magnesium and titanium. Eddy current non-destructive testing (NDT) was used to measure the electrical conductivity at different depths in transverse sections of the processed materials. The obtained profiles were compared to the hardness profiles in the same sections. As a result, a good correlation was observed in most materials welded by solid state and by fusion processes. The variation of the electrical conductivity closely follows the one detected in the hardness. Another interesting conclusion is that, even for fusion welding of carbon steels, the technique has potential to complement the hardness measurements and microstructural observations, allowing to identify the distinct zones of welds in materials commonly used in industry.

scholarly journals Welding of magnesium and its alloys: an overview of methods and process parameters and their effects on mechanical behaviour and structural integrity of the welds

2021 ◽  
Vol 8 ◽  
pp. 29
Author(s):  
Desmond Edem Primus Klenam ◽  
Gabriel Seun Ogunwande ◽  
Taiwo Omotosho ◽  
Blessing Ozah ◽  
Nthabiseng Beauty Maledi ◽  
...  
Keyword(s):  
Solid State ◽  
Process Parameters ◽  
Mechanical Behaviour ◽  
Structural Integrity ◽  
Fusion Welding ◽  
Mg Alloys ◽  
Future Research ◽  
Friction Stir ◽  
Weld Joints ◽  
Welding Processes

An overview of welding methods and process parameters and its effects on mechanical behaviour and structural integrity of magnesium and its alloys are discussed. These alloys are less dense and beneficial structural alloys for improved energy efficiency, eco-friendliness and driver of circular economic model for sustainable design and innovative ecosystem. While the application of Mg-alloys is projected to increase, understanding the mechanical behaviour and structural integrity of welded joints are critical. Thus, fusion and solid-state welding processes of these alloys are discussed with emphasis on mechanical characterization. Laser welding is the most effective fusion welding technique for most Mg alloys whereas, the predominant solid-state method is friction stir welding. The importance of process variables such as heat inputs, welding velocity (speed) and post weld treatments on the microstructural evolution, on mechanical and physical properties of the distinct zones of the weld joints are described. The weldment is the most susceptible to failure due to phase transformation, defects such as microporosity and relatively coarse grain sizes after solidification. The implication of the design of quality weld joints of Mg alloys are explored with areas for future research directions briefly discussed.

Analytical Modeling and Analysis of the Matter Flow during Friction Stir Welding

2019 ◽  
Vol 297 ◽  
pp. 1-16
Author(s):  
Zineelabidine Harchouche ◽  
Mokhtar Zemri ◽  
Abdelkader Lousdad
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Solid Phase ◽  
Welding Process ◽  
Computational Time ◽  
Modeling And Analysis ◽  
Friction Stir ◽  
Tool Pin ◽  
Welding Processes ◽  
Matter Flow

Friction stir welding is a solid-phase welding process based on the mixing of the pasty material in the stirred zone. The main advantage of this technique is the ability to weld metal alloys which are generally difficult to weld by conventional welding processes. In this paper an analytical model is proposed for the description in 2D the distribution of the material (fluid) flow in the vicinity of the tool pin during friction stir welding process "FSW". For this reason, the analytical solutions are built on the basis of traditional problem of mechanics of the fluids which is used to solve the equation associated with this problem. Furthermore, the aim is to make an analytical study of these aspects for a better understanding of this phenomenon. This method provides a reduction in computational time compared to those required for finite or differential elements methods. Moreover, it highlights on the effects of the different parameters on the material flow during welding.

scholarly journals Effects of FSW Tool Plunge Depth on Properties of an Al-Mg-Si Alloy T-Joint: Thermomechanical Modeling and Experimental Evaluation

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4754
Author(s):  
Shabbir Memon ◽  
Dariusz Fydrych ◽  
Aintzane Conde Fernandez ◽  
Hamed Aghajani Derazkola ◽  
Hesamoddin Aghajani Derazkola
Keyword(s):  
Material Flow ◽  
Defect Formation ◽  
Stir Zone ◽  
Frictional Heat ◽  
Plunge Depth ◽  
Friction Stir ◽  
Stiffened Structures ◽  
Simulation Results ◽  
Cfd Method ◽  
Welding Processes

One of the main challenging issues in friction stir welding (FSW) of stiffened structures is maximizing skin and flange mixing. Among the various parameters in FSW that can affect the quality of mixing between skin and flange is tool plunge depth (TPD). In this research, the effects of TPD during FSW of an Al-Mg-Si alloy T-joint are investigated. The computational fluid dynamics (CFD) method can help understand TPD effects on FSW of the T-joint structure. For this reason, the CFD method is employed in the simulation of heat generation, heat distribution, material flow, and defect formation during welding processes at various TPD. CFD is a powerful method that can simulate phenomena during the mixing of flange and skin that are hard to assess experimentally. For the evaluation of FSW joints, macrostructure visualization is carried out. Simulation results showed that at higher TPD, more frictional heat is generated and causes the formation of a bigger stir zone. The temperature distribution is antisymmetric to the welding line, and the concentration of heat on the advancing side (AS) is more than the retreating side (RS). Simulation results from viscosity changes and material velocity study on the stir zone indicated that the possibility of the formation of a tunnel defect on the skin–flange interface at the RS is very high. Material flow and defect formation are very sensitive to TPD. Low TPD creates internal defects with incomplete mixing of skin and flange, and high TPD forms surface flash. Higher TPD increases frictional heat and axial force that diminish the mixing of skin and flange in this joint. The optimum TPD was selected due to the best materials flow and final mechanical properties of joints.

scholarly journals Influence of Tool Tilt Angle on Material Flow and Defect Generation in Friction Stir Welding of AA2219

2018 ◽  
Vol 68 (5) ◽  
pp. 512-518 ◽  
Author(s):  
Suresh Meshram ◽  
Madhusudhan Reddy
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Tilt Angle ◽  
Material Flow ◽  
Critical Role ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir ◽  
Tool Tilt Angle ◽  
Welding Processes

Heat treatable aluminium alloy AA2219 is widely used for aerospace applications, welded through gas tungsten and gas metal arc welding processes. Welds of AA2219 fabricated using a fusion welding process suffers from poor joint properties or welding defects due to melting and re-solidification. Friction stir welding (FSW) is a solid-state welding process and hence free from any solidification related defects. However, FSW also results in defects which are not related to solidification but due to improper process parameter selection. One of the important process parameters, i.e., tool tilt angle plays a critical role in material flow during FSW, controlling the size and location of the defects. Effect of tool tilt angle on material flow and defects in FSW is ambiguous. A study is therefore taken to understand the role of tool tilt angle on FSW defects. Variation in temperature, forces, and torque generated during FSW as a result of different tool tilt angles was found to be responsible for material flow in the weld, controlling the weld defects. An intermediate tool tilt angle (1o-2o) gives weld without microscopic defect in 7 mm thick AA2219 for a given set of other process parameters. At this tool tilt angle, x-force, and Z- force is balanced with viscosity and the material flow strain rate sufficient for the material to flow and fill internal voids or surface defects in the weld.

scholarly journals Joining of dissimilar materials by friction stir welding

2018 ◽  
Vol 224 ◽  
pp. 01118 ◽  
Author(s):  
Zakaria Boumerzoug
Keyword(s):  
Friction Stir Welding ◽  
Solid State ◽  
Physical Properties ◽  
Dissimilar Materials ◽  
Total Weight ◽  
Friction Stir ◽  
Pipe Welding ◽  
Race Cars ◽  
Welding Processes ◽  
Solid State Joining

Welding is a process of joining materials into one piece. Welding is used extensively for pipe welding, aerospace, aviation, biomedical implants, fabrication of race cars, choppers, etc. Welding processes include thermal fusion joining processes and solid-state joining processes. Among solid-state joining processes, there is a friction stir welding which is applied to join two workpieces without materials. This technique of welding has great is used to weld dissimilar materials. This type of welding is gaining renewed interest, because the main objective is to reduce the total weight and maintaining essential physical properties. The objective of this paper is to focus on the friction stir welding of dissimilar materials.

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