A Study on the Thermal Deformation of Fillet Joint Friction Stir Welding

2020 ◽  
Author(s):  
Sungwook Kang ◽  
Jaewoong Kim ◽  
Donghyun Kim ◽  
Kwangjin Lee ◽  
Yoonchul Jung
Keyword(s):  
Friction Stir Welding ◽  
Heat Source ◽  
Welding Process ◽  
Frictional Heat ◽  
Process Conditions ◽  
Joint Friction ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Shape ◽  
Fillet Joint

Abstract In this study, experiments and simulations were performed for fillet joint friction stir welding according to tool shape and welding conditions. Conventional butt friction stir welding has good weldability because heat is generated by friction with the bottom of the tool shoulder. However, in the case of fillet friction stir welding, the frictional heat is not sufficiently generated at the bottom of the tool shoulder due to the shape of the tool and the shape of the joint. Therefore, it is important to sufficiently generate frictional heat by slowing the welding speed as compared to butt welding. In this study, experiments and simulations were carried out on an aluminum battery housing made by friction stir welding an extruded material with a fillet joint. The temperature of the structure was measured using thermocouple during welding, and the heat source was calculated through correlation analysis. Thermal elasto-plastic analysis of the structure was carried out using the calculated heat source and geometric boundary conditions. It is confirmed that the experimental results and the simulation results are well matched. Based on the results of the study, the deformation of the structure can be calculated through simulation even if the tool shape and welding process conditions change.

scholarly journals Influence of material velocity on heat generation during linear welding stage of friction stir welding

2016 ◽  
Vol 20 (5) ◽  
pp. 1693-1701
Author(s):  
Alin Murariu ◽  
Darko Veljic ◽  
Dragana Barjaktarevic ◽  
Marko Rakin ◽  
Nenad Radovic ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Friction Stir Welding ◽  
Heat Generation ◽  
Welding Process ◽  
Slip Rate ◽  
Frictional Heat ◽  
Al Alloy ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin

The heat generated during friction stir welding (FSW) process depends on plastic deformation of the material and friction between the tool and the material. In this work, heat generation is analysed with respect to the material velocity around the tool in Al alloy Al2024-T351 plate. The slip rate of the tool relative to the workpiece material is related to the frictional heat generated. The material velocity, on the other hand, is related to the heat generated by plastic deformation. During the welding process, the slippage is the most pronounced on the front part of the tool shoulder. Also, it is higher on the retreating side than on the advancing side. Slip rate in the zone around the tool pin has very low values, almost negligible. In this zone, the heat generation from friction is very low, because the material is in paste-like state and subjected to intensive plastic deformation. The material flow velocity around the pin is higher in the zone around the root of the pin. In the radial direction, this quantity increases from the pin to the periphery of the tool shoulder.

Effect of Friction Stir Welding Parameters on Thermal and Tensile Behavior of Aluminum Weldments Using Double Shoulder Tools

2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Tensile Behavior ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Base ◽  
Tool Pin ◽  
Strength And Ductility

Friction stir welding (FSW) process is a solid state welding process in which the material being welded does not melt or recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters and tool pin profile play major roles in deciding the weld quality. In this investigation, an attempt has been made to understand effects of process parameters include rotation speeds, welding speeds, and pin diameters on al.uminum weldment using double shoulder tools. Thermal and tensile behavior responses were examined. In this direction temperatures distribution across the friction stir aluminum weldment were measured, besides tensile strength and ductility were recorded and evaluated compared with both single shoulder and aluminum base metal.

A Thermo-Fluid Analysis of the Friction Stir Welding Process

2007 ◽  
Vol 539-543 ◽  
pp. 3832-3837 ◽  
Author(s):  
D. Jacquin ◽  
Christophe Desrayaud ◽  
Frank Montheillet
Keyword(s):  
Friction Stir Welding ◽  
Bulk Material ◽  
Welding Process ◽  
Vertical Motion ◽  
Velocity Fields ◽  
Fluid Simulation ◽  
Metal Sheet ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Fluid Analysis

The thermo-mechanical simulation of Friction Stir Welding focuses the interest of the welding scientific and technical community. However, literature reporting material flow modeling is rather poor. The present work is based on the model developed by Heurtier [2004] and aims at improving this thermo-fluid simulation developed by means of fluid mechanics numerical and analytical velocity fields combined together. These various velocity fields are investigated separately and especially according to the power dissipated during the flow. Boundary conditions are considered through a new approach based on the kinematic analysis of the thread of the pin. An equilibrium is established between the vertical motion of the bulk material dragged in the depth of the metal sheet, and its partial circulation around the pin. The analyses of the obtained velocity fields enable the understanding of the welded zone asymmetry and highlights the bulk material mixing between the welded coupons in the depth of the sheet. A regression is performed on the relative sliding velocity of the aluminium according to the surface of the tool: shoulder and pin. Two dimension flow lines in the depth of the metal sheet are then obtained and successfully compared with the results obtained by Colegrove (2004) [1].

On the problem of tool destruction when obtaining fixed joints of thick-walled aluminum alloy blanks by friction welding with mixing

2021 ◽  
Vol 23 (3) ◽  
pp. 72-83
Author(s):  
Kirill Kalashnikov ◽  
◽  
Andrey Chumaevskii ◽  
Tatiana Kalashnikova ◽  
Aleksey Ivanov ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Friction Welding ◽  
Welding Process ◽  
High Strength ◽  
Heterogeneous Structure ◽  
Adhesive Interaction ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Electric Erosion

Introduction. Among the technologies for manufacturing rocket and aircraft bodies, marine vessels, and vehicles, currently, more and more attention is paid to the technology of friction stir welding (FSW). First of all, the use of this technology is necessary where it is required to produce fixed joints of high-strength aluminum alloys. In this case, special attention should be paid to welding thick-walled blanks, as fixed joints with a thickness of 30.0 mm or more are the target products in the rocket-space and aviation industries. At the same time, it is most prone to the formation of defects due to uneven heat distribution throughout the height of the blank. It can lead to a violation of the adhesive interaction between the weld metal and the tool and can even lead to a destruction of the welding tool. The purpose of this work is to reveal regularities of welding tool destruction depending on parameters of friction stir welding process of aluminum alloy AA5056 fixed joints with a thickness of 35.0 mm. Following research methods were used in the work: the obtaining of fixed joints was carried out by friction welding with mixing, the production of samples for research was carried out by electric erosion cutting, the study of samples was carried out using optical metallography methods. Results and discussion. As a result of performed studies, it is revealed that samples of aluminum alloy with a thickness of 35.0 mm have a heterogeneous structure through the height of weld. There are the tool shoulder effect zone and the pin effect zone, in which certain whirling of weld material caused by the presence of grooves on tool surface is distinctly distinguished. It is shown that the zone of shoulders effect is the most exposed to the formation of tunnel-type defects because of low loading force and high welding speeds. It is revealed that tool destruction occurs tangentially to the surface of the tool grooves due to the high tool load and high welding speeds.

Optimization of Welding Process Parameters in Novel Friction Stir Welding of Polyamide 66 Joints

2019 ◽  
Vol 969 ◽  
pp. 828-833 ◽  
Author(s):  
R. Nandhini ◽  
R. Dinesh Kumar ◽  
S. Muthukumaran ◽  
S. Kumaran
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Polyamide 66 ◽  
Friction Stir ◽  
Response Characteristics ◽  
Tool Shoulder ◽  
Stereo Microscope ◽  
Friction Plate

The friction stir welding of polyamide 66 with a specially modified tool is studied. A variation of the conventional friction stir welding is investigated by incorporating a friction plate for the purpose of heating the polymer in the course of welding process through the tool shoulder. This in turn, improves the efficiency of the weld. The association of the welding process parameters and the weld performance has been investigated by the grey relational analysis with multi response characteristics like weld tensile strength, percent elongation and hardness. Macrostructure of the weld joint cross section has been explored by Stereo microscope. The maximum weld tensile strength of 63 MPa and a Shore hardness of 60 D at the weld nugget are obtained. The hardness profiles of the welded samples have been analyzed in this investigation.

Influences of Tool pin Profile and Tool Shoulder Curvature on the Formation of Friction Stir Welding Zone in AA6061 Aluminium Alloy

2012 ◽  
Vol 445 ◽  
pp. 789-794 ◽  
Author(s):  
Vahid Moosabeiki ◽  
Ghasem Azimi ◽  
Mostafa Ghayoor
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Zone Formation ◽  
Friction Stir ◽  
Tool Pin Profile ◽  
Tool Shoulder ◽  
Aa6061 Aluminium Alloy ◽  
Tool Pin

Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. Friction stir tool plays a major role in friction stir welding process. In this investigation, it is tried to evaluate the effect of tool pin thread and tool shoulder curvature on FSW zone formation in AA6061 aluminium alloy. In this regard, six different tool pin geometries (threadless triangular pin with/without conical shoulder, threaded triangular pin with conical shoulder, threadless square pin with/without conical shoulder, threaded square pin with conical shoulder) are used to fabricate the joints. The formation of FSP zones are analyzed macroscopically. Tensile properties of the joints are evaluated and correlated with the FSP zone formation. Consequently, it is obtained that welding creates a higher quality compared to other tool pin profiles using the square tool with curved shoulder and having threaded pin.

scholarly journals Effect of Shoulder–Workpiece Interference Depth on the Quality of Friction Stir Welding of AA7075-T6 Aluminium Alloy

2019 ◽  
Vol 26 (1) ◽  
pp. 150-159
Author(s):  
Abbas Akram Abbas ◽  
Hazim H. Abdulkadhum
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Welding Process ◽  
High Strength ◽  
Filling Defect ◽  
Welding Quality ◽  
Left Hand ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Welding Surface

The joining of high strength aluminium alloy AA7075-T6 sheets of 3 mm thickness was an attempt utilizing friction stir welding process. The effect of interference depth between tool shoulder and surface workpiece on the welding quality and its effect on the mechanical and metallography properties of welded joints were studied. This process is carried out using a composite tool consists of a concave shoulder made of H13 tool steel and cylindrical left-hand thread with 1mm pitch pin (probe) made of cobalt-based alloy MP159. The dimensions of tools were 14mm shoulder diameter and the pin has 5mm diameter and 2.7mm length. The tool rotation speed and welding speed were 981 rpm 169 mm/min respectively, and the tilt angle was 2°. The range of interference depth between the shoulder and workpiece was selected (0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) mm. various tests were executed to evaluate the welding quality. The results show that lack of filling defect appeared on the welding surface at the interference depth 0.05 mm. An invisible tunnel and lack of penetration in the bottom of the stir zone appeared when the interference depths were 0.1 mm and 0.15 mm. Defect-free welds obtained when interference depths were (0.2, 0.25, and 0.3) mm. The welding efficiency of the defect-free welds was in the range (85.3-92.3%) depending on the ultimate tensile strength of the parent alloy.

scholarly journals The Preliminary Exploration of Micro-Friction Stir Welding Process and Material Flow of Copper and Brass Ultra-Thin Sheets

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2401
Author(s):  
Changqing Zhang ◽  
Zhuo Qin ◽  
Chen Rong ◽  
Wenchen Shi ◽  
Shuwen Wang
Keyword(s):  
Friction Stir Welding ◽  
Flow Behavior ◽  
Pure Copper ◽  
Weld Zone ◽  
Metal Flow ◽  
Welding Process ◽  
Process Conditions ◽  
Friction Stir ◽  
Plastic Metal ◽  
Tool Pin

In the friction stir welding (FSW) of ultra-thin dissimilar metal sheets, different physical material properties, the reduction of plastic metal in the weld zone, and insufficient plastic metal flow lead to poor weld seam shapes and joint qualities. Therefore, it is necessary to study the flow behavior during the FSW of ultrathin sheets. In this study, micro friction stir welding (μFSW) was conducted and analyzed for the butt welding of 0.6-mm-thick ultrathin brass (H62-H) and pure copper (T2-Y) sheets. By analyzing the electric signals of the temperature and force during the welding process, testing the mechanical properties, and analyzing the metallography of the joint, the influences of the process parameters on the metal flow behavior during μFSW were studied. In the proper process conditions, the material preferentially migrated and concentric vortex flow occurred in the vicinity of the shoulder and tool pin action areas. The copper was pushed from the retreating side (RS) to the advancing side (AS) of the weld, allowing it to flow more fully. A mixture of both materials formed at the bottom of the weld nugget, and less migration occurred in the heat-affected zone of the AS at this time. The highest tensile strength can reach 194 MPa, accounting for 82.6% of the copper. The presence of brittle phases Cu5Zn8, AgZn3 and AgZn caused the hardness to fluctuate slightly.

Study on the effects of tool tile angle, offset and plunge depth on friction stir welding of poly(methyl methacrylate) T-joint

2019 ◽  
Vol 234 (4) ◽  
pp. 773-787 ◽  
Author(s):  
Arameh Eyvazian ◽  
Abdel Magid Hamouda ◽  
Hamed Aghajani Derazkola ◽  
Majid Elyasi
Keyword(s):  
Friction Stir Welding ◽  
Methyl Methacrylate ◽  
Material Flow ◽  
Welded Joint ◽  
Welding Process ◽  
Frictional Heat ◽  
Plunge Depth ◽  
Poly Methyl Methacrylate ◽  
Friction Stir ◽  
Thermomechanical Simulation

The effects of tilt angle (TTA), plunge depth (TPD) and offset (TO) of tool in friction stir welding of poly(methyl methacrylate) T-joint were investigated. To understand better the effects of process parameter, thermomechanical simulation of joint was assessed. The results seem to show that at higher TPD and TTA, frictional heat increases. Woven tissue structure joint line forms after friction stir welding of poly(methyl methacrylate) sheets. The distance of woven layers was affected by TPD and TTA, while TO do not significantly affect heat generation of joint. The best material flow and adequate heat are generated at 0 mm TA, 2° TTA and 0.2 mm TPD, respectively. The highest flexural and tensile strength of friction stir welded joint were approximately 93% and 90% of as-received poly(methyl methacrylate), respectively. Crack forking was detected on the fractured surface of flexural samples and crack path was detected in the vicinity of shrinkage holes at fracture surface of tensile samples. These holes and degradation of poly(methyl methacrylate) during friction stir welding process decrease strength and hardness of the joint.

An Experimental Study of Process Parameters on Friction Stir Welded Aluminum Alloy 2219 Joint Properties

2017 ◽  
Vol 863 ◽  
pp. 3-7
Author(s):  
Koo Kil No ◽  
Joon Tae Yoo ◽  
Jong Hoon Yoon ◽  
Ho Sung Lee
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Solid State ◽  
Process Parameters ◽  
Process Condition ◽  
Welding Process ◽  
Frictional Heat ◽  
Friction Stir ◽  
Joint Properties ◽  
Aluminum Alloy 2219

Aluminum alloy 2219 is widely used in aerospace applications since it has a unique combination of good weldability and high specific strength. Furthermore, it can provide a high strength after heat treatment with superior properties in cryogenic environment so they have been widely used for cryogenic fuel tank of space launch vehicles. It is known that solid state welding like friction stir welding can improve the joint properties of this alloy. Friction stir welding is a solid state welding technology which two materials are welded together by the frictional heat due to the rotation of the tool. In this study, friction stir welding was performed on aluminum alloy 2219 sheets. The range of welding parameter is four rotation speeds from 350 to 800 rpm and six travel speeds from 120 to 420 mm/min. The results include the microstructural change after friction stir welding. The microstructure was characterized and material in the stirred zone experience sufficient deformation and heat input which cause the complete dynamic recrystallization. The present work represents the strength at each process condition and the optimum friction stir welding process parameters. The optimum weld efficiency obtained in this study was 76.5 %.

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