Optimizing Friction Stir Welding of Al 6061 Alloy Using Statistical Analysis

Author(s):  
Dae Min Kang ◽  
◽  
Kyoung Do Park ◽  
Dai Yeal Lee ◽  
◽  
...  

In this study, a three-way factorial design is used to optimize the friction stir welding (FSW) process of Al 6061 alloy. Control factors are shoulder diameter, travel speed, and rotation speed of tool, and each factor has three levels. Tensile strength tests are also carried out to measure the mechanical properties under various FSW conditions. In this work, travel speed, shoulder diameter, and tool speed are shown to individually be meaningful factors in the tensile strength of the alloy, but interactions among the weld factors are not detected. The result of the study is that the optimum process condition for maximum tensile strength is estimated to be A3B3C3. In addition, the presumed range of tensile strength under the optimal conditions is estimated to be 257±23 (Mpa) with 95% reliability.

2011 ◽  
Vol 110-116 ◽  
pp. 3165-3170 ◽  
Author(s):  
Ghodratollah Roudini ◽  
Sajad Gholami Shiri ◽  
Masoud Mohammadi Rahvard

there are some parameters in friction stir welding (FSW) technique such as tool design, tool rotation speed and tool travel which can be controlled in a precise manner thus controlling the energy input into the system. In this study the effects of these parameters were investigated on microstructure and tensile strength of 5052 aluminum alloy. Roll sheets of this alloy were welded by FSW method at different rotation speeds (400, 800, 1600 and 2500 rpm), welding speeds (50 and 100 mm/min) and tools shoulder diameters (14 and 20 mm). The microstructure results showed that the stir zone (SZ) and thermo-mechanically affected zone (TMAZ) had dynamically recrystallized and recovered respectively. Also the tensile strength of samples welded at tool rotation speeds of 400 and 800 rpm, travel speed 50 mm/min and tools shoulder diameter of 20 mm is similar to that of base metal. The tool rotation speeds of 400 rpm have a good welding ability with higher travel speed and lower tools shoulder diameter.


2015 ◽  
Vol 813-814 ◽  
pp. 462-466 ◽  
Author(s):  
R Padmanaban ◽  
V. Muthukumaran ◽  
A. Vighnesh

Friction stir welding (FSW) has become a potential solid state joining technique with considerable advantages over conventional joining process. Defect-free friction stir welded joints with high joint strength are obtained when optimum process parameters are used. Although a large number of parameters govern the FSW process, the tool rotation speed, Welding speed and tool geometry are key parameters that influence the joint strength. In this work, a statistical model relating process parameters and the tensile strength (TS) of friction stir welded AA1100 joints is build using response surface methodology. The four independent variables are tool rotational speed (TRS), welding speed (WS), shoulder diameter (SD) and pin diameter (PD). Central Composite design is used and Analysis of Variance at 95% confidence level was applied to assess the adequacy of the developed model. Genetic algorithm is used for optimizing the parameters. The optimum process parameter values predicted using the genetic algorithm are as follows. Tool rotation speed: 1001.9 rpm; welding speed: 62 mm/min; shoulder diameter: 17.8 mm and pin diameter: 6.5 mm. The corresponding tensile strength of the joints is 73.1556 MPa


2021 ◽  
Vol 36 (1) ◽  
pp. 94-102
Author(s):  
M. M. Z. Ahmed ◽  
A. Elnaml ◽  
M. Shazly ◽  
M. M. El-Sayed Seleman

Abstract In this work, top surface lubrication during friction stir welding of polycarbonate sheets was applied. A homogenous layer of Paraffin wax has been placed on the top surface of the joint area with a width that ensures to cover the shoulder diameter. Then FSW was applied using conventional FSW tool with rotating pin and shoulder at different FSW parameters (Rotation speeds of 1 000, 1500, 2 000 min–1 and welding speeds of 25, 50, 75,100 mm/min). The main objective of using the wax is to act as a lubricant that reduces the friction between the shoulder and the polycarbonate surface. The joints produced were investigated in terms of surface quality, internal defects, and mechanical properties. During FSW the wax is melted and played as lubricant between the tool shoulder and the polycarbonate surface and resulted in defect-free surface with no thickness reduction of the original plate. The transverse cross-section showed defect-free joints for the majority of the FSW parameters investigated. Tensile testing results showed a reduction of the tensile strength after FSW, and an enhancement in the tensile strength with the increase of welding speed or rotation speed. The fracture occurs at the joint zone and the fracture surface investigation using SEM showed the existence of spherulitic structure in the weld joint.


2016 ◽  
Vol 701 ◽  
pp. 154-158
Author(s):  
Nurul Hidayah Othman ◽  
Norsyahfiana Abdul Razak ◽  
Luqman Hakim Ahmad Shah ◽  
Mahadzir Ishak

This study focuses on the effect of pin taper tool ratio on friction stir welding of aluminum AA7075. Two pieces of AA7075 alloy with thickness of 6 mm were friction stir welded by using conventional milling machine. The shoulder diameter used in this experiment is fix 18mm. The taper pin ratio used are varied at 6:6, 6:5, 6:4, 6:3, 6:2,and 6:1. The rotational speeds that were used in this study were 1000 rpm, 1200 rpm and 1400 rpm, respectively. The welding speeds used are 60 mm/min, 80 mm/min and 100 mm/min. Microstructure observation of welded area was studied by using optical microscope. To evaluate the mechanical properties of this specimen, tensile test was used in this study. Welded specimens using taper pin ratio 6:2 shows higher tensile strength compared to other taper pin ratio up to 197 MPa. Moreover, taper pin ratio 6:1 showed better tensile test compared to taper pin ratio above 6:3. The optimum parameters were found to be taper pin ratio 6:2 with 1000 rpm of rotational speed and 60mm/min welding speed.


2016 ◽  
Vol 836 ◽  
pp. 208-213
Author(s):  
Widia Setiawan ◽  
Djarot B. Darmadi ◽  
Wahyono Suprapto ◽  
Rudy Sunoko

Aluminium 6061 was joined by friction stir welding (FSW) with new surface preparation on corner design. The distribution micro structure in Corner-joints was tool welded rotation (rpm), and travel speed (mm/mnt) observed and analyzed. The welding parameters observing the tensile strength, micro structure and micro hardness it can be said. The result structure micro are homogen whilst from tensile test the strength joint is quilt good even better from preview publihsed papers. The obtained with the transverse speed 15 mm/menit, and 1500 rpm.


Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 57
Author(s):  
Andreas Dimopoulos ◽  
Achilles Vairis ◽  
Nectarios Vidakis ◽  
Markos Petousis

The aim of this work was to weld thin sheets (2 mm) of Al 7075 in a butt joint configuration using friction stir welding and to identify the appropriate tool geometry and optimum process parameters. Two tools were produced with heat treatable low alloy steel WNr 1.6582/DIN 34CrNiMo6 with a different pin diameter (3 mm and 4 mm). Welding was performed at a range of rotation speeds 1000–2500 rpm and various welding speeds 80–800 mm/min. The tensile strength was measured to evaluate mechanical properties. Results showed that despite the difficulties in friction stir welding thin plates, sound joints can be produced in a repeatable manner, without visible wear on the welding tool. The mechanical strength of the welds showed a decrease (33.75%) over that of the parent material. The mechanical strength was less affected by rotation speed than welding speed and there was a significant decrease in tensile strength compared to the parent material.


2021 ◽  
Vol 15 (4) ◽  
pp. 8644-8652
Author(s):  
Ibrahim Sabry

Demand for metal matrix composites (MMCs) is expected to increase in these applications, such as ‎in the aerospace and automotive sectors.  Adequate joining techniques, which are important for ‎structural materials, have not yet been developed for Metal Matrix Composite (MMCs), however.  ‎This work aimed to demonstrate the feasibility of ‎friction stir welding (FSW) and ‎underwater friction stir welding (UFSW) for joining Al 6061/5, Al 6061/10, and Al ‎‎6061/18 wt. %SiC composites have been produced by utilizing reinforce stir casting technique. Two ‎rotational ‎speeds,1000and 1800 rpm, and traverse speed 10mm \ min were examined. Specimen ‎composite plates 10 mm thick have been successfully welded by FSW. For FSW and UFSW, a tool ‎made of high-speed steel (HSS) with a conical pin shape was used. The result revealed that the ‎ultimate tensile strength of the welded joint by FSW and UFSW at rotation speed 1800 rpm for (Al ‎‎6061/18 wt. ‎‎% SiC composites) was 195 MPa and 230 MPa respectively. The ultimate ‎tensile ‎strength of the welded joint by FSW  and UFSW (Al 6061/18 wt.% SiCe composites) was 165 MPa ‎and 180 MPa at rotation speed ‎‎1000 rpm respectively. The microstructural assessment showed that due ‎to larger grain sizes at FSW and UFSW, most of the fractures are located in the thermal ‎mechanically affected zone (TMAZ) adjacent to the weld nugget zone (WNZ). It is observed that in ‎failure, most of the joints show ductile features. As the volume fraction of SiC (18 wt.%) increases, ‎the friction stir welded and underwater friction stir welded efficiency decreases.


Author(s):  
Ugrasen Gonchikar ◽  
Holalu Venkatadasu Ravindra ◽  
Prathik Jain Sudhir ◽  
Umeshgowda Bettahally Mahadevegowda ◽  
Shankarnarayan Maskibail Suresh

Abstract Friction Stir Welding (FSW) is a solid state welding which uses non-consumable steel rod to weld two materials. Friction stir welding is an emerging process which is based on frictional heat generated through contact between a non-consumable rotating tool and work piece. Friction stir welding technique possesses several advantages over other conventional types of welding due to the fact that process is carried out in solid state. Removal of melting helps in minimizing porosity and eliminates oxide inclusion. In this study, we focus on the optimization of the process parameters in friction stir welding of two different aluminium alloys (6061, 7075) using Taguchi method of experimental design. Al 6061 and Al 7075 are the two different alloys of aluminium. Among these Al 7075 has mechanical properties nearly double than that of Al 6061, but Al 6061 is used more extensively than Al 7075 because of its low cost. Al 6061 and Al 7075 being alloys of aluminium varies in the composition of alloying elements used in their manufacturing. Al 6061 has magnesium and silicon as its major alloying elements whereas Al 7075 has zinc as its primary alloying element. Al 6061 comes with medium to high strength, exhibit good toughness and surface finish, excellent resistance to corrosion at environmental conditions and another important property is its good weldability. Al 7075 being stronger than Al 6061 lacks in its resistance to corrosion and has poor weldability. Al 6061 is readily weldable but Al 7075 is not, because it is prone to micro-cracking during welding. This study also describes the relation between process parameters and their response of friction stir weld on ultimate tensile strength and hardness of composite materials using mathematical models. The process parameters considered are rotational speed, welding speed and number of passes. Different methodologies are used to develop the models to predict the responses and mechanical properties such as ultimate tensile strength and hardness. The objective of Multiple Regression Analysis (MRA) is to construct a model that explains as much as possible, the variability in a dependent variable, using several independent variables. Group Method of data Handling Technique (GMDH) is a family of inductive algorithms for computer-based mathematical modelling of multi-parametric datasets that features fully automatic structural and parametric optimization of models. GMDH is used in such fields as data mining, knowledge discovery, prediction, complex systems modelling, optimization and pattern recognition. As the machining process is non-linear and time dependent, it is difficult for the traditional identification methods to provide an accurate model. Compared to traditional computing methods, the Artificial Neural Network’s (ANN) are robust and global. Estimation and comparison of machining responses were carried out by MRA, GMDH and ANN.


Author(s):  
T. Kasirajan ◽  
R. Ravindran ◽  
T. Ramkumar ◽  
M. Selvakumar

This work deals with the joining of 6 mm thick dissimilar aluminium plates (AA5083-H111 and AA6082-T6) using a friction stir welding method and by varying the process parameters. Test experiments were performed to identify the influence of process parameters on the joint efficiency of the weldments. The process parameters such as tool rotation speed and tool pin profile were varied; whereas, tool travel speed, tilt angle, and axial force were kept constant for all weldments. Microstructure evaluation was carried out using light optical and scanning electron microscopes, which exposed the grain refinement in the nugget zone (NZ) and thermo-mechanical affected zone (TMAZ). Mechanical property tests for tensile strength, hardness, and bending were performed to understand the influence of the parameters over the weldments. Heat development between the tool shoulder and workpiece was analyzed by calculating the heat flow and heat flux. The thermal diffusivity of AA5083-H111 and AA6082-T6 were calculated to understand the influence of heat distribution in the joint efficiency of the weldments. It is inferred from the current study that the threaded cylinder tool at a rotational speed of 900 rpm achieved the highest tensile strength, hardness, and bend strength over the combination of other parameters.


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