Top PDF The influence of rotational speed in the Friction Stir Welding of 6082-T6 aluminium alloy joints

The influence of rotational speed in the Friction Stir Welding of 6082-T6 aluminium alloy joints

The influence of rotational speed in the Friction Stir Welding of 6082-T6 aluminium alloy joints

Rotational speed in friction stir welding is one of the most important parameters which needs to be optimized in order to attain hot weld conditions and quality, [Rodrigues et al., 2010]. In order to perform Friction Stir Welding (FSW) on 6082-T6 aluminium alloy plates, the rotational speed of the tool should correlate with the material to achieve good results; taking into consideration that different aluminium alloys react differently to varying welding speeds. It remains a challenge to find optimum parameters for welding similar 6082-T6 aluminium alloy. Literature shows that there is a lot of work that has been done with the purpose of improving the quality of the welds. Most of the works vary the rotational speed together with the welding speed. This type of analysis does not really give a concrete conclusion around these parameters. This study investigates the impact of varying rotational speeds while keeping the welding speed constant during FSW of 6082-T6 aluminium alloy bought at Non-Ferous Metal Works Cape Town.
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Radiography and Corrosion Analysis of Sub-merged Friction Stir Welding of AA6061-T6 Alloy

Radiography and Corrosion Analysis of Sub-merged Friction Stir Welding of AA6061-T6 Alloy

aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. In FSW, a non- consumable rotating tool with a special geometry, consisting of a pin and a shoulder sweeps the weld seam, and joins the work pieces while traversing along the seam. Major process parameters such as rotational speed and feed rate, influence the quality of the welds. These parameters are responsible for generating the frictional heat and creating the stirring mechanism that joins the materials effectively [2, 3]. In recent years, the particular interest is to improve the joint properties by controlling the temperature level. For this, the whole work piece is immersed in the liquid during the welding which is called Submerged Friction Stir Welding (SFSW) [4, 5]. Tokisue et al [6] were the first to use submersion in a friction joining process.
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A Study of Aluminium 6082 & Brass 319 Materials by Friction Stir Welding Process

A Study of Aluminium 6082 & Brass 319 Materials by Friction Stir Welding Process

Abstract — This paper contains the report of study of Aluminium-6082 to Aluminium-6082 and Brass- 319 to Brass-319 welding joints weld by Friction stir welding process. The size of the work pieces used for the welding is (50mm x 35mm x 5mm) . Friction stir welding process allows achieving high quality joint when compared to conventional welding process. This paper mainly focuses on the welded joints of Aluminium and Brass.The main welding parameters which have a great influence on welding joints are Rotational speed, transverse speed and depth of cut. In this study the Rotational speed of the tool were varied from 710 to 1120 Rpm and tranverse speed were kept at 20 mm/min and depth of cut is maintained at 4.5mm throughout the experiment. The welded joints were then subjected to mechanical testing such as tensile testing,hardening test and microscopy of the welded joints.As per the reports of tensile testing,hardening test the welded joint of Aluminium is having high strength at the optimum speed of 900Rpm and the corresponding tensile strength is 173.19N/mm 2 . For Brass the joint having high strength when the speed is 710 Rpm and the respective tensile strength is 231.360N/mm 2 . Then the microscopy test is conducted as per the Standard of ASTME112 on the high tensile strength welded joints at 200x magnification and then brinells hardness test is conducted on the samples.
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Optimization of Welding Parameters for Friction Stir Lap Welding of AA6061 T6 Alloy

Optimization of Welding Parameters for Friction Stir Lap Welding of AA6061 T6 Alloy

Friction Stir Welding (FSW) is currently used in many aircraft and aerospace sheet metal structures involving lap joints and there has been growing interest in recent years in utilizing this process for joining aluminum alloys. In this paper, Friction Stir Lap Welding (FSLW) of the 6061-T6 aluminum alloy was carried out to obtain the optimum welding condition for maximum shear strength where the rotational speed, axial load, and welding speed were taken as process parameters. An L-9 orthogonal array, a Taguchi Method with con- sideration of three levels and three factors was designed and executed for conducting trials. Analysis of variance (ANOVA) and Signal to Noise (S/N) ratio were employed to investigate the influence of different welding parame- ters on the shear strength and obtain the optimum parameters. The Fish- er-Test was also implemented to find the design parameter which had the most important effect on the characteristic of quality. The results indicated that the tool rotational speed had the maximum percentage contribution (51%) on the response (shear strength) followed by the welding speed (38%) and the axial load (8%) while the percentage of error was 3%. However, to confirm the main effects for the means and S/N ratios of the experiment, theoretical shear strength values were computed to predict the tensile strength. The maximum shear strength of 60 MPa was achieved and the effec- tiveness of the method was confirmed. The optimum parameter combinations that provided higher shear strength were: rotational speed of 1200 rpm, weld- ing speed of 45 mm/min and the axial load of 11.5 kN.
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Influence of tool rotational speed, feed rate and tool material on mechanical properties of friction stir welded AA6061 and AA6082 Aluminium alloy

Influence of tool rotational speed, feed rate and tool material on mechanical properties of friction stir welded AA6061 and AA6082 Aluminium alloy

Friction stir welding is a solid state welding process which uses a non-consumable tool to weld workpieces. The process of welding is accomplished by the help of heat generated by the action of rubbing between tool and workpiece. The quality of the weld joint is majorly depends on the different process parameters like tool rotational speed, feed rate, tilt angle and tool profile. [1] In the recent advancements of technology joining of different alloys, materials are playing a major role in order to reduce weight and to increase the strength of the final product. This can be achieved by the help of friction stir welding and it easily joins the materials which are soft than the tool used in the process of welding. [2]
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EVALUATION OF PARAMETERS OF FRICTION STIR WELDING FOR ALUMINIUM AA6351 ALLOY

EVALUATION OF PARAMETERS OF FRICTION STIR WELDING FOR ALUMINIUM AA6351 ALLOY

Friction Stir Welding (FSW) is a solid state welding process in which the relative motion between the tool and the work piece produces heat which makes the material of two edges being joined by plastic atomic diffusion. This method relies on the direct conversion of mechanical energy to thermal energy to form the weld without the application of heat from conventional source. The rotational speed of the tools, the axial pressure and welding speed and the (weld time) are the principal variables that are controlled in order to provide the necessary combination of heat and pressure to form the weld. These parameters are adjusted so that the interface is heated into the plastic temperature range (plastic state) where welding can take place. During the last stage of welding process, atomic diffusion occurs while the interfaces are in contact, allowing metallurgical bond to form between the two materials. The functional behaviour of the weldments is substantially determined by the nature of the weld strength characterized by the tensile strength, metallurgical behavior, surface roughness, weld hardness and micro hardness. In this project an attempt is made to determine and evaluate the influence of the process parameters of FSW on the weldments. The Vickers hardness, tensile strength and radiography are considered for investigation by varying tool speed, tool feed and maintaining constant depth of penetration of weld. Experiments were conducted on AA6351 Aluminium alloy in a CNC Vertical Machining Centre. The output factors are measured in UTM, Vickers hardness tester and Radiography equipment. Results show strong relation and robust comparison between the weldment strength and process parameters. Hence FSW process variable data base is to be developed for wide variety of metals and alloys for selection of optimum process parameters for efficient weld.
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Material characterization and optimisation of friction stir welds of 6061-T6 aluminium alloy

Material characterization and optimisation of friction stir welds of 6061-T6 aluminium alloy

In this study, the effect of rotational speed and traverse speed on the micro – and macrostructure, and mechanical properties (tensile and microhardness properties) of friction stir butt-welded 6061-T6 aluminium alloy has been investigated. A number of research studies have been conducted on friction stir welding of various aluminium alloys, the rotational and traverse speeds were noticed to have a greater influence on the formation of a quality weld. In this study, welds were fabricated from different parameter combinations by varying the rotational and traverse speeds during the welding procedure. The rotational speeds employed representing the low, medium and high settings are 700, 900, and 1100 rpm respectively while the traverse speeds utilised were 60, 80, and 100 mm/min traverse speeds. To ascertain the joint integrities, the welds were characterised through hardness, microstructure, and tensile tests. The hardness test was performed along the cross-section of the welds. The changes in the microstructure and hardness were analysed and further correlated to the tensile strength of the 6061-T6 aluminium alloy. Optical microscope and Scanning Electron Microscope were used for microstructural analysis. Instron machine and Vickers hardness machine were used to perform tensile and hardness tests, respectively. The results showed that the grain size decreased from the heat affected zone (HAZ) towards the centre of the nugget zone (NZ) due to the stirring during the FSW process. The average hardness in the NZ decreased when the rotational speed varied from 700 rpm to 900 rpm, and then increased with a further increase in the rotational speed to 1100 rpm at constant traverse speeds of 60, 80 and 100 mm/min.
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EFFECT OF ROTATIONAL SPEED ON TENSILE STRENGTH & MICRO HARDNESS OF FRICTION STIR WELDED AL2014 & AL5083- ALUMINIUM ALLOY

EFFECT OF ROTATIONAL SPEED ON TENSILE STRENGTH & MICRO HARDNESS OF FRICTION STIR WELDED AL2014 & AL5083- ALUMINIUM ALLOY

Friction Stir Welding (FSW) is a solid state welding process to join materials by generating frictional heat between a rotating tool and materials being welded. It was invented at The Welding Institute (TWI), Cambridge (U.K.) in 1991. Since then FSW has become a major joining process in the aerospace, railway and ship building industries especially in the fabrication of aluminum alloys. It is difficult to weld the aluminum alloys, using arc welding, gas welding and other welding processes. Friction Stir Welding on the other hand, can be used to join most Al alloys and better surface finish is achieved. Although the work piece does heat up during friction stir weld, the temperature does not reach the melting point. In this research work, rotational speed is considered for experimentation to weld Al alloy AL2014 & AL5083 and their effect on mechanical properties such as tensile strength, and micro hardness of Heat Affected Zone, Thermo Mechanical Affected Zone and weldament. The influence of welding parameters has been presented in graphical form for better understanding. With the increase in tool rotational speed, coarse grain structure is produced, which resulted in low ultimate tensile strength and low impact strength. On the other hand high welding speed results in low heat input which improves the cooling rate, leaving a fine grained structure. This in turn increases ultimate strength and increases impact strength. With the increase in rotational speed, rate of heat input increases, which results in coarse microstructure, which in turn decreases the hardness. But at the same time increase in welding speed lowers the rate of heat input results in higher cooling rate and fine microstructure. Fine microstructure results in increased hardness.
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Investigation of Mechanical Properties of Aluminium 6061 Alloy Friction Stir Welding

Investigation of Mechanical Properties of Aluminium 6061 Alloy Friction Stir Welding

of aircraft structures, such as wings and fuselages, more commonly in homebuilt aircraft than commercial or military aircraft. Aluminium 6061 alloy generally present low weldability by traditional fusion welding process. The development of Friction Stir Welding (FSW) has provided an alternative improved way of satisfactorily producing weld joint in aluminium 6061 alloy. In FSW, the welding tool motion induces frictional heating and severe plastic deformation and metal joining process is done in solid state results, which results in defect free welds with good mechanical properties in aluminium alloy 6061. Unlike in traditional fusion welding, friction stir welds will not encounter problems like porosity alloy segregation and hot cracking, and welds are produced with good surface finish. In this paper, an attempt was made to investigate the impact of process parameters of FSW in the mechanical properties of the joint. The tensile properties, microstructure, hardness of the FSW joints were investigated in the weldment and heat affected zone. The changes of mechanical properties are compared with the parental metal. The welding parameters such as tool rotational speed and welding speed plays a major role in deciding the joint characteristics. This paper focusses on optimization of all these parameters. From this investigation it was found that the joint made from the FSW yielded superior tensile properties and impact strength due to the higher hardness and fine microstructure.
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Friction Stir Welding of AA5052& AA6061 Aluminium Alloy by using Taguchi Method

Friction Stir Welding of AA5052& AA6061 Aluminium Alloy by using Taguchi Method

rpm) and transverse feed of (100 mm/min) at constant axial force 2KN. This shows that tool tilt angle, rotational speed, welding speed are the important parameters in deciding the ultimate tensile strength of the weld joint. The dissimilar joint was tested, micro hardness survey, and microstructure. This dissimilar friction stir welded butt joints are keeping AA 6061 plate on the advancing side and AA5052 plate on the retreating side.

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DEFECTS ANALYSIS OF T-JOINT FRICTION STIR WELDED SAMPLES OF ALUMINIUM ALLOY 6101-T6

DEFECTS ANALYSIS OF T-JOINT FRICTION STIR WELDED SAMPLES OF ALUMINIUM ALLOY 6101-T6

The main aim is to study micro structural properties of FSW Butt T-joints of AA 6101-T6 and further detail analysis of defects occured.FSW T-joint setup is developed on vertical milling machine of HMT make. Friction stir welding of Al 6101-T6 alloy (material used for bus bar conductor, requiring minimum loss of electrical conductivity and good mechanical properties) was performed in butt T-joint configuration using varying welding speed and rotary speed. A good T -joint of AA 6101 is achieved with this setup. Welded samples have post processed and prepared for microstructure analysis. Field emission scanning electron microscope is used to take micro structural images. After analysis of these images it is found that a satisfactory T-joint is achieved. Further explained detail analysis of defects occurred in weld specimen.
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Optimization of Friction Stir Welding Process Parameters of Aluminium alloy AA7075 T6 by using Taguchi Method

Optimization of Friction Stir Welding Process Parameters of Aluminium alloy AA7075 T6 by using Taguchi Method

In this study, Vikas, Mandeep Singh [6] use Al 6063 T6 is used as working material. Process parameters rotatory speed, traverse speed and in order to find their impact on tensile strength, the axial force is varied. The test was scheduled in the Taguchi orthogonal array L9. S / N ratios analyze the best possible setting parameters and ANOVA determines the contribution from the input parameter. Al6063 alloy butt joint specification with threaded cylindrical pin by FSW technique was successfully developed. They use rotational speeds 850rpm, 1050rpm, 1200rpm, traverse speeds 40mm/min, 58mm/min, 78mm/min and axial forces are 4kN, 5kN, 6kN.The optimal combination for FSW process parameters is a spindle speed of 1200 rpm, a translational feed of 78mm / min, an axial load of 6 KN, which achieves maximum tensile strength. .The maximum contribution of translation feed was 81.31% and rotational velocity was 15.44% accompanied by axial force with minimal influence of 2.03% on tensile strength. B. Influence of Tool Pin Geometric shapes on Friction Stir Welded similar Aluminum Alloy Joints In this study, an effort was produced to evaluate the tensile strength under distinct tool pin geometries of comparable joints of FSW structural aluminum alloy plates. .The instrument pin geometries used in this investigation were triangular, rounded and hexagonal. In this case study, AA 6082-T6 sheets 200 mm X 80 mm X 8 mm were used. Based on ASTM-B557, the 19.05 mm wide and 158.57 mm2 cross sectional area were prepared.(refer fig. 2 Tensile Test sample) .Then tensile test was performed on UTM to define the tensile strength of 9 samples were welded using different pin profiles. .
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Mechanical Behaviour of Friction Stir Welding Joints of Aluminium alloy of AA6351 with AA6351 and AA6351 with AA5083

Mechanical Behaviour of Friction Stir Welding Joints of Aluminium alloy of AA6351 with AA6351 and AA6351 with AA5083

The tensile properties and fracture locations of the welded joints are dependent on rotational speed of the tool and other process parameters like rotational speed, welding speed and axial force of the tool, tool tilt angle etc. The lower rotational speed results lower heat input and defects like crack and pinholes in friction stir processed zone and resulted lower tensile values. On the other hand when the rotational speed increases (1400 rpm and 1500 rpm), the heat input also increases which results poor tensile properties due to rise in temperature, which increases grain growth, higher rotational speed also effects in the metallurgical change like re- precipitation, solubilisation and coarsening of strengthening precipitates at the weld zone area and lowering of dislocation density [19].
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Corrosion behaviour of friction stir welded lap joints of 6061-t6 aluminum alloy

Corrosion behaviour of friction stir welded lap joints of 6061-t6 aluminum alloy

Actually, this comprehensive study is the first report attempting to quantify the corrosion evaluation of FSLW in AA6061-T6 aluminium alloy according to welding parameters and process sensitivity. The goals of the present study is to evaluate the influence of FSW parameters mainly ω and ν on the microstructure and mechanical properties of AA6061-T6 and then corrosion behaviors of desirable AA 6061-T6 welded lap joints. In this study, parametric studies were performed involving a lap type of weld including process parameters such as rotation speed (ω, rpm) and welding speed (ν, mm/min). Different rotation speeds and welding speeds were determined according to predefine welding process parameters. Overlap shear tensile testing and micro- hardness measurement was conducted for evaluating the effect of the FSW process on the mechanical properties of weldments. Metallography examinations of weldments structure (i.e. macro and micro) was performed for investigating the influence of the FSW process on the microstructure of AA6061-T6 aluminum alloy. According to ASTM standards, corrosion behaviors of desirable AA 6061-T6 welded lap joints was examined by using various corrosion test methods including immersion test (i.e. intergranular corrosion test, ASTM G110) and potentiodynamic polarization tests (i.e. Tafel plots and pitting scans, ASTM G59 &G61). Optical microscopy (OM), atomic force microscopy (AFM), and field emission scanning electron microscopy (FE-SEM) equipped with dispersive energy X-ray (EDX) analysis were utilized for characterizing the weldment microstructures.
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The Study of Rotational and Traversal Speeds Effect on Mechanical Properties Of 7075 Aluminium Alloy Friction Stir Welding

The Study of Rotational and Traversal Speeds Effect on Mechanical Properties Of 7075 Aluminium Alloy Friction Stir Welding

Abstract: FSW has been successfully used to weld similar and dissimilar cast and wrought aluminium alloys, especially for aircraft aluminium alloys generally present low weldability by traditional fusion welding process. In this article, effects of rotational and traversal speeds on the microstructure and mechanical properties of friction stir-welded 7075-T6 Al alloys were investigated. Good correlation existed between the rotational and traversal speeds and weld properties. It was found that with increase in the rotational and traversal speed, wider thickness of the heat-affected zone were obtained, and then grain coarsening, dissolution, and accumulation of hardening precipitates in grain boundaries. In addition, the highest toughness during tensile test was obtained at moderate rotational and traversal speeds of 325 r/min and 30 mm/min. However, the highest micro hardness was obtained at moderate rotational and traversal speeds of 325 r/min and 60 mm/min. It was imposed high temperature which cause of this different.
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Effect of Pin less Mild Steel Tool on Friction Stir Welding for Joining Aluminium 6082 Plates

Effect of Pin less Mild Steel Tool on Friction Stir Welding for Joining Aluminium 6082 Plates

R. Palanivel et al. (2012) [7]used FSW to join 6 mm thick dissimilar aluminium alloys AA5083-H111 and AA6351- T6 and studied the effect of tool rotational speed and pin profile on the microstructure and tensile strength of the joints. Dissimilar joints were made using three different tool rotational speeds of 600 rpm, 950 rpm and 1300 rpm and five different tool pin profiles of straight square (SS), straight hexagon (SH), straight octagon (SO), tapered square (TS), and tapered octagon (TO). The tool rotational speed and pin profile considerably influenced the microstructure and tensile strength of the joints. The joint which was fabricated using tool rotational speed of 950 rpm and straight square pin profile yielded highest tensile strength of 273 Mpa.
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Review on Thermal Analysis of Friction Stir Welding of Aluminium 5083 Alloy

Review on Thermal Analysis of Friction Stir Welding of Aluminium 5083 Alloy

M. M. El-Sayed et al. [9] used a 3D transient heat transfer model was developed by ABAQUS software. This paper is to study the temperature distribution during friction stir welding process at different rotational speeds. Moreover, AA 5083-O plates were joined by FSW method. The joints were friction stir welded at a constant travel speed 50 mm/min and two rotational speed values; 400 rpm and 630 rpm using two types of tools; cylindrical threaded pin and tapered smooth one. The maximum crest temperature obtained was at higher rotational speed using the threaded tool pin profile. Moreover, the threaded tool gives superior mechanical properties than the tapered one at lower rotational speed. Tomotake Hirata et al. [10] In his study, the effect of FSW process parameters on the grain size of the stir zone and the formability of FS-welded 5083 Al alloy was examined. The microstructures of the stir zones consisted of fine equiaxed grains at a variety of FSW circumstances in FS-welded 5083 Al alloy. The tensile strength under each FSW condition was almost the same. However the formability in FS-welded 5083 Al alloy was improved by decreasing the friction heat flow.
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Analysis of Structure and Shear/Peel Strength of Refill Friction Stir Spot Welded 7075-T6 Aluminium Alloy Joints

Analysis of Structure and Shear/Peel Strength of Refill Friction Stir Spot Welded 7075-T6 Aluminium Alloy Joints

In the aforementioned tests, the focus was placed on considering the effect of welding time on the shear and peel strength of joints. It showed unanimously that in the range of welding times be- tween 1.5-2.5 s that the longer welding improves the quality of the joint. The flaws of joints made with short welding times like structural weak points and discontinuity of the weld structure like voids are unacceptable in high responsibility structures. It was shown that the static strength of a joint when subject to the aforementioned load directions can have a high value, but in the case of fatigue strength, the weld containing defects is unacceptable. The study only considers the pa- rameter of penetration time of the tool into the welded sheet metal, showing that the lower time does not allow for achieving good temperature conditions required for proper phase change in the joint. In order to achieve correct temperature conditions, the rotational speed of the tool can also be manipulated, which is the topic of future research. Generally, it is paramount to determine the optimal parameters that ensure the desired quality of joints while considering the criteria like tool durability and the economics of the pro- cess. From the point of view of tool lifespan and process costs, welding time should be as short as possible. The tool dive depth can also be manipu- lated. In regards to tool lifespan, the depth should be as shallow as possible.
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Mechanical properties optimization of friction stir welded lap joints in aluminium alloy

Mechanical properties optimization of friction stir welded lap joints in aluminium alloy

involves combining DOE with response surface method- ologies (RSMs), more efficiently to evaluate the effectiveness of investigative trade-offs [16]. One of the most important advantages of using DOE techniques is extrapolation [17]. This property is significant because it allows optimum prediction even if “optimum” lies outside the initial design range, and the number of runs must be reduced to achieve optimum. Good predictive properties allow DOE association with other complex mathematical methods without com- promising accuracy and assuring the method of steepest ascent. This method is a viable technique for sequentially moving toward the optimum response [18]. A compre- hensive recitation of additional advantages of these DOE techniques is beyond the scope of this paper. Several papers deal with the influence of process parameters on properties of FSW joints [19–22]; in particular, it was adopted a DOE to investigate such influence [23]. From the literature, it is also evident that the main process parameters that need to be investigated are the rotational speed and travel speed [24– 26]. In particular, it was proved that the inverse of travel speed measurements was better than travel speed to fit experimental data [27]. Therefore, this study examined the strength of FSW aluminium alloy lap joints in two different welding zones: HAZ and nugget zone. Aiming to test sep- arately the tensile strength of HAZ and nugget zone, minispecimens from both these zones were subjected to shear and microhardness tests. The process parameters optimization issue was approached using central factorial design, response surface methods, and gradient algorithms. 2. Materials and Methods
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Experimental Investigation on Aluminium Alloy 6061-T6 Using Multi Profile Tool by Friction Stir Welding

Experimental Investigation on Aluminium Alloy 6061-T6 Using Multi Profile Tool by Friction Stir Welding

ABSTRACT: Friction stir welding (FSW) is a relatively new solid-state joining process. It is an emerging solid state joining process in which the material that is being welded does not melt and recast .This joining technique is energy efficient, environment friendly, and versatile. The principal advantages are low distortion, absence of melt related defects and high joint strength. In FSW parameters play an important role like tool design and material, tool rotational speed, welding speed and axial force. This paper focuses on process parameters that are required for producing effective friction stir welding joints by using two types of tool pin profile for the welding of Aluminum alloy 6061-T6 and to find out the best tool pin profile.
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