scholarly journals Bobbin Tool Friction Stir Welding of Aluminum Thick Lap Joints: Effect of Process Parameters on Temperature Distribution and Joints’ Properties

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4585
Author(s):  
Mohamed M. Z. Ahmed ◽  
Mohamed I. A. Habba ◽  
Mohamed M. El-Sayed Seleman ◽  
Khalil Hajlaoui ◽  
Sabbah Ataya ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Welding Speed ◽  
Travel Speed ◽  
Lap Joints ◽  
Stir Zone ◽  
Maximum Temperature ◽  
Al Alloy ◽  
Friction Stir ◽  
Pin Geometry ◽  
Zone Temperature

Bobbin tool friction stir welding (BT-FSW) is characterized by a fully penetrated pin and double-sided shoulder that promote symmetrical solid-state joints. However, control of the processing parameters to obtain defect-free thick lap joints is still difficult and needs more effort. In this study, the BT-FSW process was used to produce 10 mm AA1050-H14 similar lap joints. A newly designed bobbin tool (BT) with three different pin geometries (cylindrical, square, and triangular) and concave shoulders profile was designed, manufactured, and applied to produce the Al alloy lap joints. The experiments were carried out at a constant tool rotation speed of 600 rpm and a wide range of various welding travel speeds of 200, 400, 600, 800, and 1000 mm/min. The generated temperature during the BT-FSW process was recorded and analyzed at the joints’ center line, and at both advancing and retreating sides. Visual inspection, macrostructures, hardness, and tensile properties were investigated. The fracture surfaces after tensile testing were also examined. The results showed that the pin geometry and travel speed are considered the most important controlling parameters in BT-FSW thick lap joints. The square (Sq) pin geometry gives the highest BT-FSW stir zone temperature compared to the other two pins, cylindrical (Cy) and triangular (Tr), whereas the Tr pin gives the lowest stir zone temperature at all applied travel speeds from 200 to 1000 mm/min. Furthermore, the temperature along the lap joints decreased with increasing the welding speed, and the maximum temperature of 380 °C was obtained at the lowest travel speed of 200 mm/min with applying Sq pin geometry. The temperature at the advancing side (AS) was higher than that at the retreating side (RS) by around 20 °C. Defect-free welds were produced using a bobbin tool with Cy and Sq pin geometries at all the travel welding speeds investigated. BT-FSW at a travel speed of 200 mm/min leads to the highest tensile shear properties, in the case of using the Sq pin. The hardness profiles showed a significant effect for both the tool pin geometry and the welding speed, whereas the width of the softened region is reduced dramatically with increasing the welding speed and using the triangular pin.

scholarly journals Thermo-mechanical analysis of linear welding stage in friction stir welding - influence of welding parameters

2021 ◽  
pp. 186-186
Author(s):  
Darko Veljic ◽  
Marko Rakin ◽  
Aleksandar Sedmak ◽  
Nenad Radovic ◽  
Bojan Medjo ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Heat Generation ◽  
Welding Speed ◽  
Reaction Force ◽  
Material Model ◽  
Element Model ◽  
Welding Parameters ◽  
Al Alloy ◽  
Friction Stir ◽  
Fsw Parameters

The influence of friction stir welding (FSW) parameters on thermo-mechanical behaviour of the material during welding is analysed. An aluminium alloy is considered (Al 2024 T351), and different rotating speed and welding speed are applied. Finite element model consists of the plate (Al alloy), backing plate and welding tool, and it is formed and solved in software package Simulia Abaqus. The influence of the welding conditions on material behaviour is taken into account by application of the Johnson-Cook material model. The rotation of the tool affects the results: if increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, the plastic deformation of the material, is negligibly changed. When the welding speed is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming increases. Combined, these two effects cause small change of the total heat generation. For the same welded joint length, the plate welded by lower speed will be heated more intensively. The changes of the heat generation influence both the temperature field and reaction force, which are also considered.

scholarly journals Friction Stir Welding with Low-Medium-High Tool Travel Speed of 0.95 Mg-Al-Alloy and Pure Copper: Electrochemical and Surface Studies

2018 ◽  
Author(s):  
Neetesh Soni ◽  
Ambrish Singh
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Pure Copper ◽  
Travel Speed ◽  
Localized Corrosion ◽  
Al Alloy ◽  
Kelvin Probe ◽  
Friction Stir ◽  
Surface Optical ◽  
Joining Process

The aim of this work is to assess the influence of Friction Stir Welding (FSW), process parameters, optimized tool traveling speed, and corrosion resistance of the 0.95 Mg-Al-alloy and pure copper weldment. Samples of aluminum-copper with and without deformation were characterized to investigate the metallurgical effects created during the welding deformation process. Effect of process parameters on microstructure and corrosion rate have been investigated for all the samples. All the electrochemical and polarization tests were done in 3.5 wt.% NaCl solution. Scanning Kelvin Probe (SKP) was done to detect the localized corrosion on the surface. Optical micrography observation indicated that the primary α-Al phase, which was formed during solidification can effectively limit the growth of Cu9Al4 phase. Finer acicular α-Al precipitates were observed in CuAl matrix during joining process that tends to coarser with the increase in tools travel speed. The electrochemical and polarization results showed that among all the tool travelling speed the specimen joined at tool travelling speed of 40 mm/min shows the best non-corrosive property.

Experimental Estimation of Strain Rate during FSW of Al-Alloy Using Plane-Strain Compression

2008 ◽  
Vol 580-582 ◽  
pp. 299-302 ◽  
Author(s):  
Kunitaka Masaki ◽  
Yutaka S. Sato ◽  
Masakatsu Maeda ◽  
Hiroyuki Kokawa
Keyword(s):  
Strain Rate ◽  
Plane Strain ◽  
Travel Speed ◽  
Plane Strain Compression ◽  
Stir Zone ◽  
Grain Structure ◽  
Al Alloy ◽  
Strain Rates ◽  
Friction Stir ◽  
Grain Structures

Friction stir welding (FSW) makes the stir zone with fine recrystallized grain structure. The recrystallized grains would be formed through dynamic recrystallization at high temperatures and high strain-rate. The present study experimentally simulated the dynamically recrystallized microstructure of a friction stir welded Al alloy 1050 produced at 600 rpm rotation and 100 mm/min travel speed, using combination of the plane-strain compression at various strain rates and the subsequent cooling along the cooling cycle of FSW. The equiaxed grain structures similar to the microstructure of the stir zone were produced at strain rates between 0.1 and 32 s-1; the grain size decreased with increasing strain rate. Strain rate during the FSW could be estimated to be about 1.8 s-1. The present study suggests that plane-strain compression test can simulate the recrystallized grain structure of the friction stir welds.

Effect of process parameters on temperature and force distribution during friction stir welding of armor-marine grade aluminum alloy

2020 ◽  
Vol 235 (1-2) ◽  
pp. 144-154 ◽  
Author(s):  
Shubham Verma ◽  
Joy Prakash Misra
Keyword(s):  
Friction Stir Welding ◽  
Real Time ◽  
Process Parameters ◽  
Tilt Angle ◽  
Welding Speed ◽  
Low Cost ◽  
Maximum Force ◽  
Maximum Temperature ◽  
Force Distribution ◽  
Friction Stir

This research investigates the effect of process parameters on real-time temperature and forces distribution during friction stir welding of AA7039. Experiments are conducted at different rotational speed, welding speed, and tilt angle conditions. For the experimentation, a low-cost real-time force-measuring fixture is indigenously developed in-house. However, eight K-type L-shaped thermocouples are used to examine the real-time temperature distribution. The forces in the z-direction are of a higher magnitude than the x-direction. The maximum force in the z-direction of 3.25 kN is witnessed for 2° tilt angle and a minimum of 2.1 kN for 26 mm/min of welding speed. The maximum force in the x-direction of 0.97 kN is obtained at 2° tilt angle and a minimum of 0.27 kN is obtained at 1.3° tilt angle. The maximum temperature of 390 °C is observed at 1812 r/min, whereas a minimum of 283 °C is observed at 43 mm/min of welding speed. The variations in temperature and force distribution during friction stir welding are also evaluated by utilizing two phenomenological models.

Experimental Study on Friction Stir Welding of Dissimilar Al 6061 to Trip 780/800 Steel

2014 ◽  
Author(s):  
Xun Liu ◽  
Shuhuai Lan ◽  
Jun Ni
Keyword(s):  
Friction Stir Welding ◽  
Cross Sections ◽  
Welding Speed ◽  
Rotational Speed ◽  
Maximum Temperature ◽  
Friction Stir ◽  
Al 6061 ◽  
Tool Axis ◽  
Edge Temperature ◽  
Welding Force

Friction stir welding (FSW) of dissimilar Al 6061 and TRIP 780/800 steel has been performed under different process parameters, including tool rotational speed, welding speed as well as the relative position of the tool axis to the abutting edge. Temperature and mechanical welding force was recorded during the process. Welding speed has an insignificant effect on either the maximum temperature or welding force. However, it can directly change the length of high temperature duration, which will accordingly influence temperature distribution in the weld and the microstructure. Higher rotational speed can effectively elevate weld temperature through greater amount of heat input. Metallurgical observations on weld cross sections perpendicular to the joint line was performed using both optical and scanning electron microscope. Microstructure evolution was analyzed and related to the force and temperature measurement results during the FSW process.

Investigation of Microstructure and Mechanical Properties of Friction Stir Lap Jointed Ni Base Superalloy

2012 ◽  
Vol 724 ◽  
pp. 481-485
Author(s):  
Kuk Hyun Song ◽  
Kazuhiro Nakata
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Friction Stir Welding ◽  
Base Material ◽  
Lap Joints ◽  
Stir Zone ◽  
Inconel 600 ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

This study evaluated the microstructure and mechanical properties of friction stir welded lap joints. Inconel 600 and SS 400 as experimental materials were selected, and friction stir welding was carried out at tool rotation speed of 200 rpm and welding speed of 100 mm/min. Applying the friction stir welding was notably effective to reduce the grain size of the stir zone, as a result, the average grain size of Inconel 600 was reduced from 20 μm in the base material to 8.5 μm in the stir zone. Joint interface between Inconel 600 and SS 400 showed a sound weld without voids and cracks. Also, the hook, along the Inconel 600 alloy from SS 400, was formed at advancing side, which directly affected an increase in peel strength. In this study, we systematically discussed the evolution on microstructure and mechanical properties of friction stir lap jointed Inconel 600 and SS 400.

Effects of Heat Dissipation from Friction Stir Welding to Microstructures of Semi-Solid Cast 6063 Al Alloy

2021 ◽  
Vol 904 ◽  
pp. 70-75
Author(s):  
Chaiyoot Meengam ◽  
Kittima Sillapasa ◽  
Yotsakorn Pratumwal ◽  
Somboon Otarawanna
Keyword(s):  
Friction Stir Welding ◽  
Heat Dissipation ◽  
Maximum Temperature ◽  
Al Alloy ◽  
Element Analysis ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Measurement Results ◽  
6063 Al Alloy ◽  
Semi Solid

In this work, temperature distribution in semi-solid cast 6063 aluminum alloy workpieces during friction stir welding (FSW) was determined by finite element analysis (FEA). The FEA results were validated by comparing them with the measurement results from thermocouples. The maximum temperature of 534.2oC was predicted at the workpiece surface contacted with the tool shoulder. The temperature profiles obtained from FEA were used to explain microstructural changes during FSW. It was observed that relatively high temperature made α-Al grains became elongated and Mg2Si intermatalics turned into a rod-like morphology with round edges.

Dissimilar Materials Joining between SSM 356-T6 and AA6061-T651 by Friction Stir Welding

2013 ◽  
Vol 372 ◽  
pp. 478-485 ◽  
Author(s):  
Chaiyoot Meengam ◽  
Muhamad Tehyo ◽  
Prapas Muangjunburee ◽  
Jessada Wannasin
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
Rotation Speed ◽  
Stir Zone ◽  
Weld Nugget ◽  
Friction Stir ◽  
Tool Rotation Speed ◽  
Base Materials ◽  
Tool Rotation

The aim of this research is to study the influence of welding parameters on the metallurgical and mechanical properties of friction stir welded butt joints of dissimilar aluminum alloy sheets between Semi-Solid Metal (SSM) 356-T6 and AA6061-T651 by Friction Stir Welding (FSW). The base materials of SSM 356-T6 and AA6061-T651 were located on the advancing side (AS) and on the retreating side (RS) respectively. The base materials were joined under different tool rotation speeds and welding speeds. The material flows from SSM 356 and AA6061-T651 were clearly visible in the weld nugget. In addition, the mixtures of fine equiaxed grain were observed in the stir zone. The increase in tool rotation speed results in the increase in tensile strength of the joints. As for welding speed associated with various tool rotation speeds, an increase in the welding speed affected lesser the base materials tensile strength up to an optimum value; after which its effect increased. Tensile elongation was generally greater at greater tool rotation speed. An averaged maximum tensile strength of 206.3 MPa was derived for a welded specimen produced at the tool rotation speed of 2,000 rpm associated with the welding speed of 80 mm/min. In the weld nugget, higher hardness was observed in the stir zone than in the thermo-mechanically affected zone. Away from the weld nugget, hardness levels increased back to the levels of the base materials.

Finite Element Analysis and Simulation of Al 7075 Alloy Joints Produced by Friction Stir Welding

2015 ◽  
Vol 766-767 ◽  
pp. 1116-1120
Author(s):  
R. Ramesh ◽  
S. Suresh Kumar ◽  
V. Sivaraman ◽  
R. Mohan
Keyword(s):  
Finite Element ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
Axial Load ◽  
Maximum Temperature ◽  
Element Analysis ◽  
Friction Stir ◽  
Element Simulation ◽  
Al 7075 ◽  
7075 Alloy

The present work is mainly carried out to study the distribution of temperature in friction stir welded plate of Aluminium alloy. A 3-D finite element simulation model was developed to predict temperature distribution and residual stress in Friction Stir Welding (FSW) of Al 7075 alloy. The effect of angular velocity of tool, axial load and welding speed on the heat generated between the tool and plate to be welded was investigated. The simulations obtained were based on three factor five level central composite rotatable design. Second order polynomial equations for predicting the temperature was developed. Residual stresses for friction stir welded plates due to thermal cycles were predicted. The maximum temperature developed in friction stir welded plated increases with the increase of rotational speed of tool and axial load where as it decreases with increase in welding speed.

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