Estimation and Comparison of Welding Responses Using MRA, GMDH and ANN Technique of Al6061 and Al7075 Material in FSW

2019 ◽  
Author(s):  
Ugrasen Gonchikar ◽  
Holalu Venkatadasu Ravindra ◽  
Prathik Jain Sudhir ◽  
Umeshgowda Bettahally Mahadevegowda ◽  
Shankarnarayan Maskibail Suresh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Solid State ◽  
Ultimate Tensile Strength ◽  
Process Parameters ◽  
Alloying Elements ◽  
Friction Stir ◽  
Al 6061 ◽  
Al 7075

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.

Prediction and optimization of the mechanical properties of dissimilar friction stir welding of aluminum alloys using design of experiments

2016 ◽  
Vol 232 (8) ◽  
pp. 1384-1394 ◽  
Author(s):  
R Palanivel ◽  
RF Laubscher ◽  
S Vigneshwaran ◽  
I Dinaharan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Ultimate Tensile Strength ◽  
Design Of Experiments ◽  
Process Parameters ◽  
Welding Process ◽  
Friction Stir ◽  
Friction Stir Welding Process

Friction stir welding is a solid-state welding technique for joining metals such as aluminum alloys quickly and reliably. This article presents a design of experiments approach (central composite face–centered factorial design) for predicting and optimizing the process parameters of dissimilar friction stir welded AA6351–AA5083. Three weld parameters that influence weld quality were considered, namely, tool shoulder profile (flat grooved, partial impeller and full impeller), rotational speed and welding speed. Experimental results detailing the variation of the ultimate tensile strength as a function of the friction stir welding process parameters are presented and analyzed. An empirical model that relates the friction stir welding process parameters and the ultimate tensile strength was obtained by utilizing a design of experiments technique. The models developed were validated by an analysis of variance. In general, the full impeller shoulder profile displayed the best mechanical properties when compared to the other profiles. Electron backscatter diffraction maps were used to correlate the metallurgical properties of the dissimilar joints with the joint mechanical properties as obtained experimentally and subsequently modeled. The optimal friction stir welding process parameters, to maximize ultimate tensile strength, are identified and reported.

scholarly journals Investigation of microstructure and mechanical characteristic of underwater friction stir welding for Aluminum 6061 alloy – Silicon carbide (SiC) metal matrix composite

2021 ◽  
Vol 15 (4) ◽  
pp. 8644-8652
Author(s):  
Ibrahim Sabry
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Ultimate Tensile Strength ◽  
Metal Matrix ◽  
Welded Joint ◽  
Rotation Speed ◽  
Friction Stir ◽  
Al 6061 ◽  
Underwater Friction Stir Welding ◽  
Sic Composites

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.

Study on Mechanical Behaviors in Friction Stir Welding of 6061-T4 T-Joints

2011 ◽  
Vol 418-420 ◽  
pp. 1092-1096
Author(s):  
Guang Zhou ◽  
Xin Qi Yang ◽  
Xiao Dong Xu
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Ultimate Tensile Strength ◽  
Process Parameters ◽  
Heat Affected Zone ◽  
Base Material ◽  
Mechanical Behaviors ◽  
T Joints ◽  
Friction Stir

Friction stir welding (FSW) of T-joints composed by 3mm thick 6061-T4 alloy was presented and the influences of process parameters on hardness profiles and tensile strength were discussed specifically. Two low hardness zones on the skin and one low hardness zone on the stringer were found. Tensile behaviors of T-joints were examined in two directions—in skin direction and in stringer direction. It was found that the tensile strength ranged from 170~180MPa for all specimens in the skin direction. And the specimens failed in heat affected zone (HAZ) corresponding to the lowest hardness. In the stringer direction, most fractures occurred in the stringer. In all the cases, the specimens welded exhibited the best tensile strength with ω/v=1541/218 in the stringer direction. The ultimate tensile strength was equal to 83% compared to base material.

Effect of friction stir welding parameters on the material flow, mechanical properties and corrosion behavior of dissimilar AA5083-AA6061 joints

2021 ◽  
pp. 095440622110361
Author(s):  
Kethavath Kranthi Kumar ◽  
Adepu Kumar ◽  
MVNV Satyanarayana
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Corrosion Behavior ◽  
Process Parameters ◽  
Material Flow ◽  
Stir Zone ◽  
Friction Stir ◽  
Notch Tensile Strength ◽  
Mechanical Properties And Corrosion

Material flow has a significant impact on the joint properties and is one of the most challenging aspects to be understood in dissimilar friction stir welding. The present study emphasizes the role of process parameters on material flow, mechanical properties and corrosion behavior of dissimilar friction stir welds of AA5083-AA6061. Microstructural analysis revealed that the onion ring sub-layer width observed at the stir zone was substantially changed by varying process parameters. It was understood that the higher rotational speeds promote better intermixing and enhanced mechanical properties. The notch tensile strength values were in correlation with the intermixing of materials at the stir zone and the highest notch tensile strength value was obtained at 1400 rpm and 60 mm/min. A remarkable degree of material intermixing and fragmentation of intermetallics at higher rotational speeds resulted in better corrosion resistance.

scholarly journals Effect of process parameters on mechanical properties of AA5052 joints using underwater friction stir welding

2020 ◽  
Vol 14 (1) ◽  
pp. 6259-6271
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanish Paramaguru ◽  
Mokhtar Awang ◽  
Hamed Mohebbi ◽  
Sharma V Korada
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Welding Parameters ◽  
Fracture Characterization ◽  
Friction Stir ◽  
Weld Joints ◽  
Underwater Friction Stir Welding

Underwater Friction Stir Welding (UFSW) is a solid-state joining technique which uses a non-consumable tool to weld metals. The objective of this investigation is to evaluate the mechanical properties of the AA5052 Aluminium alloy joints prepared by UFSW. The effect of different type of welding tools and welding parameters on the weld joint properties are studied. Square, tapered cylindrical and taper threaded cylindrical type of welding tools have been used to produce the joints with the tool rotational speed varying from 500 rpm to 2000 rpm while the welding speed varying from 50 mm/min to 150 mm/min. Tensile strength, micro-hardness distribution, fracture features, micro-and macrostructure of the fabricated weld joints have been evaluated. The effect of welding process parameters that influences the mechanical properties and fracture characterization of the joints are explained in detail. A maximum Ultimate Tensile Strength (UTS) value of 222.07 MPa is attained with a gauge elongation of 14.78%. Microstructural evaluation revealed that most of the fracture are found on the thermal mechanically affected zone (TMAZ)adjacent to the weld nugget zone (WNZ) due to bigger grain sizes. It is found that most of the joints exhibit ductile characteristics in failure. Fractography analysis has been used to find the behavior of weld joints in failure.

Multi-response optimization of friction stir welding process parameters for dissimilar joining of Al6101 to pure copper using standard deviation based TOPSIS method

2019 ◽  
Vol 233 (18) ◽  
pp. 6473-6482 ◽  
Author(s):  
Nidhi Sharma ◽  
Zahid A Khan ◽  
Arshad Noor Siddiquee ◽  
Mohd Atif Wahid
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Ultimate Tensile Strength ◽  
Process Parameters ◽  
Welding Speed ◽  
Welding Process ◽  
Micro Hardness ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Response Optimization

Friction stir welding is a new and effective solid-state welding process for joining dissimilar materials such as aluminum (Al) and copper (Cu). Joint quality of the friction stir welded materials gets influenced by the welding strategy and different friction stir welding process parameters, i.e. rotational speed, welding speed, tool design, tool pin offset, and tilt angle. In this paper, the effect of combination of different friction stir welding process parameters during joining of Al-6101 and pure copper is studied using Taguchi L18 orthogonal array. Four friction stir welding process parameters, i.e. shoulder diameter (A), pin offset (B), welding speed (C), and rotational speed (D) each at three levels except shoulder diameter, which is at two levels are selected. The effect of different combinations of these parameters on ultimate tensile strength and micro-hardness of the joints is investigated. Subsequently, single response optimization for ultimate tensile strength and micro-hardness and multi-response optimization of ultimate tensile strength and micro-hardness taken together is carried out to obtain the optimal combination of the friction stir welding process parameters. Taguchi method is used for single response optimization, whereas Taguchi-based TOPSIS method is employed for multi-response optimization. For single optimization, the optimum combination of the friction stir welding parameters yielding maximum strength and micro-hardness are A1B1C2D2 and A2B1C2D3, respectively. The optimum combination of the process parameters for multi-response optimization is A2B1C2D2. From the results of the study for single- and multi-response optimization, it is revealed that the rotational speed is the most significant process parameter affecting the tensile strength and micro-hardness of the joints followed by the welding speed. Further, the macro/microstructure and micro-hardness profile of the joint obtained at the optimal combination of the multi-response optimization are given and discussed for better understanding of material mixing and joining.

Optimization of Process Parameters of Friction Stir Welding by Taguchi Method

2019 ◽  
Vol 7 (1) ◽  
pp. 17-23
Author(s):  
Azzam Sabah Albunduqee ◽  
Hussein R Al-Bugharbee
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Taguchi Method ◽  
Process Parameters ◽  
Rotational Velocity ◽  
Welding Parameters ◽  
Optimum Process ◽  
Friction Stir ◽  
Optimization Of Process Parameters

Friction Stir Welding is one of the technologies of joining solid states, which still attracts the researchers’ interest.  In welded joints the mechanical properties are affected by a number of mechanical properties of the joined materials and by the process parameters as well. In the present study, the effect of a number of friction stir welding parameters on the tensile strength of the welded joint have been investigated using the Taguchi method and the analysis of variance (ANOVA). The study considers different levels of friction stir welding variables; namely, different rotational speeds of (2000, 1600, 1250 rpm), different welding speeds (12.5, 16, 20 mm / min), and different welding tilt angles (0, 1, 2 degrees).  The optimum process parameters and their contribution rate were selected based on the Taguchi method for test design and by using the Minitab 16 program. In this study, the best results (i.e, higher tensile strength) were obtained at a rotational velocity of 1600 rpm, linear velocity of 16 mm / min, and welding angle, 1o. The highest tensile strength was obtained under these conditions.                                                                                       

Robotic Friction Stir Welding of AA5754 Aluminum Alloy Sheets at Different Initial Temper States

2014 ◽  
Vol 622-623 ◽  
pp. 540-547 ◽  
Author(s):  
Massimo Callegari ◽  
Archimede Forcellese ◽  
Matteo Palpacelli ◽  
Michela Simoncini
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Speed ◽  
Process Condition ◽  
Hybrid Structure ◽  
Welding Parameters ◽  
Friction Stir ◽  
Robotic Friction Stir Welding

Robotic friction stir welding experiments were performed on AA5754 aluminium alloy sheets, 2.5 mm in thickness, in two different temper states (H111 and O-annealed). A six axes robot with a hybrid structure, characterised by an arm with parallel kinematics and a roll-pitch-roll wrist with serial kinematics, was used. The effect of the process parameters on the macro-and micro-mechanical properties and microstructure of joints was widely analysed. It was shown that, under the same process condition, the mechanical properties of the joints are strongly influenced by the initial temper state of the alloy. In particular, as AA5754-H111 is welded, the ultimate tensile strength is not significantly affected by the process parameters whilst the ultimate elongation significantly depends on the welding speed. In AA5754-O, both ultimate values of tensile strength and elongation are affected by the welding speed whilst a negligible effect of the rotational speed can be observed. Irrespective of the welding parameters, the H111 temper state leads to mechanical properties higher than those given by the O-annealed state. An investigation has been also carried out in order to evaluate the micro-hardness profiles and microstructure of the FSWed joints in order to understand the mechanisms operating during robotic friction stir welding.

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