Optimizing the Friction Stir Spot Welding Parameters to Attain Maximum Strength in Dissimilar Joints of Aluminum and Carbon Steel

Author(s):  
Sundaram Manickam ◽  
Visvalingam Balasubramanian

The present investigation is aimed at optimizing the friction stir spot welding (FSSW) process parameters such as tool rotational speed, plunge rate, dwell time and tool diameter ratio, to attain the maximum strength in dissimilar joints of AA6061 aluminum and carbon steel. Experiments were conducted according to the four factor, five level central composite rotatable design matrix. Strength of the joints was evaluated by means of single lap shear test. Optimization was done by response surface method (RSM). A maximum tensile shear fracture load (TSFL) of 9.46 kN was exhibited by a joint welded using following parameters: tool rotational speed of 1000 rpm, plunge rate of 4 mm/ min, dwell time of 5 sec and tool diameter ratio of 3.0.

2017 ◽  
Vol 867 ◽  
pp. 105-111
Author(s):  
S. Ramesh Babu ◽  
M. Nithin ◽  
S. Pavithran ◽  
B Parameshwaran

The Electrical Resistance Welding (ERW) of Magnesium and Aluminium is more difficult than steel because the welding machines must provide high currents and exact pressures in order to provide the heat necessary to melt the magnesium for proper fusion at the interface in order to produce a sound weld. Further, resistance welding of magnesium requires a backup plate made of steel to conduct the heat to the workpiece material. To overcome this problem, Friction Stir Spot Welding (FSSW) has been developed. In this study, the hardness distribution and the tensile shear strength of FSSW welds in the AZ31B Magnesium alloy has been investigated and it has been found that tool rotational speed and dwell time plays a major role in determining the weld strength. From the experimental study, a tool rotational speed of 1100 rpm and dwell time of 20 s produced good shear strength of 2824 N and the corresponding grain size was 4.54 μm. This result is very well supported by microstructural examinations and hardness distribution studies.


2018 ◽  
Vol 9 (1) ◽  
pp. 51-58
Author(s):  
Adnan A. Ugla ◽  
◽  
Ahmed O. Al- Roubaiy ◽  
Falih H. Alazawi ◽  
◽  
...  

Author(s):  
Sudhir Kumar ◽  
◽  
Sachin Jambhale ◽  
Manish Maurya ◽  
Sanjeev Kumar ◽  
...  

This experimental work investigates the tensile behavior of friction stir spot welded joints from 3 mm thick aluminum alloy AA6082-T6 sheets. Taguchi L9 Orthogonal array was used for process parameters - Tool rotational speed (TRS), Dwell time (DT) and Shoulder diameter (SD) with consideration of three levels. Friction Stir Spot Welding (FSSW) was performed on vertical milling machine. Tensile shear test was conducted on Universal testing machine (UTM) to find out the tensile shear failure load (TSFL). The optimal combinations of parameters were at tool rotational speed of 2,000 rpm, dwell time of 15 seconds and tool shoulder diameter of 16 mm. Tool rotational speed had a substantial effect on tensile shear strength of FSSW joint. Scanning Electron Microscopy (SEM) tests revealed that the changes in microstructure in different zones of FSSW joint were observed. Tensile shear specimen was analyzed using SEM to observe the behavior of fracture surfaces. Significant ductility in the fracture surface was an evident in the fractography. In this article, attention is focused on the influence of joining parameters on the mechanical behavior of the friction stir spot weld under the tensile shear load condition. Keywords: Fractography; friction stir spot welding (FSSW); heat affected zone (HAZ); scanning electron microscopy (SEM); thermo-mechanically affected zone (TMAZ).


2018 ◽  
Author(s):  
Ahmed Mahgoub ◽  
Abdelaziz Bazoune ◽  
Fadi Al-Badour ◽  
Necar Merah ◽  
Abdelrahman Shuaib

In this paper, a Coupled Eulerian Lagrangian (CEL) finite element model (FEM) was developed to simulate the friction stir spot welding (FSSW) of commercial pure copper. Through simulations results, the paper presents and discusses the effect of FSSW process parameters; namely rotational speed, plunging rate and dwell time, on the developed temperatures and their distribution within the workpiece as well as material flow and deformation. Model validation showed a good agreement between predicted temperature history and the experiment one, with a maximum error of 6%. Furthermore, the predicted formation of flash was also found in good agreement with the experiment with an error of only 7%. Simulation results predicted peak temperature and plastic strain among all studied welding conditions were 920 K and 3.5 respectively at 1200 rpm rotational speed, 20 mm/min plunging rate and 4 seconds dwell time, which is approximately 70% of the melting point of pure copper.


2019 ◽  
Vol 3 (2) ◽  
pp. 59
Author(s):  
Pathya Rupajati ◽  
Pathya Rupajati

Abstrak  Salah satu karakteristik sifat mekanis yang penting untuk dianalisis adalah tensile shear load. Penelitian ini bertujuan untuk melakukan optimasi tensile shear load hasil pengelasan micro friction stir welding (µFSSW) pada material AA1100 dan Cu1100P menggunakan metode Taguchi. Rancangan percobaan yang digunakan dalam penelitian ini adalah matriks orthogonal array L8 dengan memvariasikan parameter proses pengelasan yaitu dwell time dan plunge depth yang memiliki masing-masing empat level dan dua level. Sedangkan variabel konstan yang digunakan adalah tool rotational speed sebesar 33.000 rpm. Hasil penelitian menunjukkan bahwa parameter pengelasan yang memiliki kontribusi terbesar dalam meningkatkan tensile shear load hasil pengelasan micro friction stir spot welding adalah dwell time, yang menghasilkan tensile shear load sebesar 265,12 N dengan seting kombinasi dwell time pada 5 s dan plunge depth pada 0,7 mm. Hasil struktur mikro juga menunjukkan terlihat adanya flash dan hook defect, tetapi tidak menujukkan adanya intermetallic compound dan crack. Kata kunci: A1100, µFSSW, Taguchi, Dwell time, Plunge Depth


Author(s):  
Ahmed Mahgoub ◽  
Neçar Merah ◽  
Abdelaziz Bazoune

Abstract Friction Stir Spot Welding (FSSW) is a solid-state joining technique widely applied to high conductive metals. In this paper, the effects of FSSW parameters, namely, rotational speed (N), plunging rate (V) and dwell time (DT) on the joint fracture mode and fractured surface morphology were investigated using scanning electron microscopy (SEM). The effect of the abovementioned welding parameters on the microhardness profile along the sheets’ interface was also investigated to gain insight into the strength of the joint and the width of the bonding ligament. Two conditions were considered for each parameter 1200 rpm and 900 rpm for N, 60 mm/min and 20 mm/min for V, 4 and 2 seconds for DT. The welding condition 1200 rpm rotational speed, 20 mm/min plunging rate and 2 seconds dwell time showed a wider bonding ligament, relatively higher elongation, higher tensile failure load, and greater microhardness on the sheets’ interface. Dimple surface morphology (DSM) with regular dimples along the stir zone was also observed at the abovementioned set of process parameters.


2013 ◽  
Vol 765 ◽  
pp. 776-780 ◽  
Author(s):  
S. Venukumar ◽  
S. Muthukumaran ◽  
Y. Swaroop

Aluminium and magnesium alloys are expected to make considerable contributions in reducing the weight of automobiles as they are increasingly used as an alternative to steel; improving fuel economy and vehicle performance while simultaneously reducing emissions. Higher electrical and thermal conductivities of these materials make them difficult to weld using existing resistance spot welding leading to high energy consumption. Friction stir spot welding has proven to be a better alternative to weld these materials. But a probe hole left behind is the main problem in conventional Friction Stir Spot welding (FSSW). In the present work a new method has been developed to refill the probe hole using an additional filler plate known as Refill Friction Stir Spot welding (RFSSW). This new refilling technique and the conventional FSSW process were both used to weld commercially pure aluminium lap shear specimens and the results were compared. The effect of tool rotational speed on mechanical and metallurgical properties were studied in both cases. Static shear strength of RFSSW weld samples was found to be better than conventional FSSW process at higher tool rotational speed. This is explained in terms of effective increase in cross sectional area of weld nugget due addition of more material from the filler plate thereby eliminating the probe hole.


2019 ◽  
Vol 269 ◽  
pp. 02004
Author(s):  
Bintang Adhi Guna ◽  
Nurul Muhayat ◽  
Triyono

Friction stir spot welding (FSSW) was developed to join the dissimilar materials as an alternative for replacing the resistance spot welding (RSW). In the case of dissimilar metals welded between aluminum and galvanized steel, Zn can decompose and diffuse in both steel and aluminum so it can increase the joint strength. Due to this reason, it is important to explore the Zn distribution based on the parameter of the friction stir spot welding. The lap joint configuration was used in this work where aluminum plate was placed on the top of steel. Aluminum thickness was 3 mm, while steel thickness was 1 mm. The constant depth of plunge, dwell time, and penetration rate were 2.7 mm, 3 seconds, and 0.9 mm/sec respectively. Flat tool with diameters of 10 mm, 12 mm and 14 mm were used for FSSW processes and for each flat tool diameter, four levels of the rotational speed of 1000 rpm, 1200 rpm, 1600 rpm and 2000 rpm were performed. The Zn distribution was evaluated using the SEM and EDS analysis. Due to the heat generation during FSSW process, materials around the tools will soften and then flow to follow the centrifugal force. The rotational speed and the flat tool diameter affected the distance and the shape of Zn diffusion flow. The distance of Zn diffusion both horizontal and vertical direction increased as increasing the rotational speed and the flat tool diameter.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Aditya Noor ◽  
Nurul Muhayat ◽  
. Triyono

<p><em>Friction stir spot welding (FSSW) is one of the development of solid state welding to joint lightweight materials such as aluminium. In the automotive industry, lightweight materials are needed in the structure of vehicle construction to improve efficiency in vehicles. This research aims to find out how the effect of rotational speed and dwell time on physical and mechanical properties on the weld joint of aluminium 1100 with Zn interlayer addition. Variations used in rotational speed 1000, 1250, 1600 rpm and dwell time 6, 7, 8 s. Pullout fracture occur in tensile tests that are getting bigger with increasing rotational speed and dwell time. The results of SEM and EDS observations showed that the metallurgical bonded zone increased and kept the hook defect away. The spread of Zn in the stir zone area causes the formation of solid Al-Zn phase in a solid solution. The hook defect filled with Zn can minimize cracks that occur, so increased the tensile shear load. The highest tensile shear load value of FSSW AA1100 without Zn interlayer is 3.61 kN, while the FSSW AA1100 with Zn interlayer addition is 4.34 kN.</em></p>


Author(s):  
Ahmed Kamal Mahgoub ◽  
Abdelaziz Bazoune ◽  
Fadi A. A. Al-Badour ◽  
Abdelrahman Shuaib ◽  
Gihad Mohamed Karrar

Friction stir spot welding (FSSW) is an appropriate process to join materials that are difficult to weld using fusion welding, such as copper. In this paper, an experimental study to weld lap joint of pure copper plates having a dimensions of 100 × 30 × 2 mm is performed, successful spot weld is obtained at tool rotational speed of 1200 rpm, feed rate of 20 mm/min for dwell time of 2 seconds. The tool used in the FSSW has a threaded pin of 5 mm diameter, length of 3.7 mm, and a scrolled shoulder of 11.52 mm diameter. Tensile test and microhardness were performed for the joint and it showed reasonable weld strength. In addition, a numerical model was developed, and the estimated temperatures as well as weld macrostructure matched very well with experimental results.


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