Conventional welding processes are unsuitable for welding the heat treatable alloy (AA6061), making it necessary for it be examined by other welding methods such as Frictionstirwelding (FSW). The frictionstirwelding technology is being widely considered by the modern aerospace and automotive industry for high performance structural demanding application. The problem arises here is that the heat treatable alloy (AA6061) used in our test is used to in the production of very critical applications or equipment such as aircrafts where there is no space for any compensation. So, this alloy should has the high mechanicalproperties. This aluminumalloy (6XXX) is challenging to weld via conventional welding processes, mostly owing to the poor solidification microstructure and the presence of porosity in the fusion zone, and the loss of mechanicalproperties. These factors make the connecting of this alloy via conventional welding processes unattractive. It is known that aluminum alloys are hard to weld, mostly due to its high thermal conductivity and the potential of forming defects, such as porosity and solidification cracking. This makes them unsuitable for aerospace or other similar applications.
The main objective of this research is to conduct an investigation into the effect of weldingparameters on the microstructural and mechanicalproperties of frictionstir (FS) welded butt joints of dissimilar aluminumalloy AA6061 and AA7075. Frictionstirwelding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. This will be used to join aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. In this process, two metal pieces, AA6061 and AA7075, 100 x 50 x 6mm thick, are welded under different weldingparameters like tool rotation speed and transverse feed. The effects of weldingparameters were evaluated by studying the resulting mechanicalproperties such as hardness distribution and tensile properties for axial welded zone.
The aim of this work is to analyse the process of frictionstirwelding (FSW) of 3 mm thick aluminium plates made of high strength aluminium alloy - 2024 T3, as well as to assess the mechanicalproperties of the produced joints. FrictionStirWelding is a modern procedure which enables joining of similar and dissimilar materials in the solid state, by the combined action of heat and mechanical work. This paper presents an analysis of the experimental results obtained by testing the butt welded joints. Tensile strength of the produced joints is assessed, as well as the distribution of hardness, micro-and macrostructure through the joints (in the base material, nugget, heat affected zone and thermo-mechanically affected zone). Different combinations of the tool rotation speed and the welding speed are used, and the dependence of the properties of the joints on these parameters of welding technology is determined.
Actually, this comprehensive study is the first report attempting to quantify the corrosion evaluation of FSLW in AA6061-T6 aluminium alloy according to weldingparameters 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 mechanicalproperties 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 mechanicalproperties 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-T6aluminumalloy. 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.
Response surface methodology (RSM)  is an interaction of mathematical and statistical techniques for modelling and optimizing the response variable models which several independent variables influence a dependent variable or response and the goal is to optimize the response  Experiments have been carried out according to the experimental plan based on central composite rotatable second-order design (CCD)matrix with the star points being at the center of each face of factorial space was used,. The upper limit of a factor was coded as +1, and the lower limit was coded as –1. The “face-centered CCD” involves 20 experimental observations at three independent input variables. The experimental Frictionstirweldingparameters and their levels in this study in the actual form is given in Table 2
Frictionstirwelding (FSW) is a welding process which deals with joining parts in a solid state at low temperature to result in welded parts with excellent mechanical performance, such as low distortion and high tensile strength. Additionally frictionstirwelding is applicable to aluminumalloy products with precision dimensions. By using frictionstirweldingparameters, this research studies the tensile strength, hardness, elongation rates, and shrinkage of extruded 6061-T6alloy. Results indicate that the joining strength of the extruded 6061-T6alloy can reach 78% of the base metal after frictionstirwelding. Meanwhile, weldingparameters can accurately predict and control the welding distortion of welded products. This research applies these results in the manufacturing of launch boxes to arrive at a technology that can be directly applied to welded products without expensive as-welded modiﬁcations. [doi:10.2320/matertrans.L-MRA2008829]
FrictionStirWelding (FSW) is a solid-state welding process, invented at the Welding Institute (TWI) in 1991 . Joining takes place by means of a non-consumable rotating tool with a threaded pin to provide a combination of frictional heating by the tool shoulder, and stirring of the soft material by the pin along the joint line. It is important to avoid overheating since the temperature must be maintained to be below the solidus of the equilibrium phase diagram for the materials being joined. The main advantage is its ability to join metals without melting precludes the risk of traditional defects found in fusion welds such as liquidation cracking, solidification cracking, or oxide formation. Frictional heat generated by rotation of the tool due to the high normal pressure and shearing action of the shoulder along the joint line causes a softened zone of material without melting. This softened material cannot escape outside as it is under constrained extrusion by the tool shoulder. As the tool travels along the joint line, material is moved around the tool probe between the retreating side of the tool and the surrounding non-deformed material. The mixed and extruded material is deposited to form a mechanically mixed joint in solid state behind the tool . After cooling, a solid phase bond is created in microstructure of metal that has been stirred and mixed together. This process requires low energy input and joins materials without consumable filler metals, sparks, fumes, or shielding gas, so it is a kind of green technology. It is energy efficient and produces reliable products with automated process and improved productivity . In addition, in most cases the localized heat during frictionwelding results in a refined microstructure, which can provide improved strength relative to the parent material. Key process parameters include travel speed, rotational speed, normal compressive load, and fixture geometry. The details of the tool geometry are crucial for determining optimum condition and usually are proprietary. The purpose of the current study was to study the frictionstirwelding process on mechanical and microstructural properties of Aluminumalloy 2195-T0 and T8. Since FSW is both a deformation and a thermal process, microstructural evolution during FSW is evaluated. The microstructure and mechanicalproperties of weldments were investigated for different welding conditions so that the optimum welding condition is determined for different heat treated alloys.
Optimizing the Process Parameters of FSW. The significant of this paper is to discuss mechanicalproperties of overlap and conventional joints for aluminum alloys for the first time. One of the common joint in mechanical engineering design is overlap joints the nature of the challenges in design process is how can we decide the type of joint in primary design for different application. Previous work in this field all compare welded joint with different tools and different materials work piece .in this project we want to compare the mechanicalproperties of conventional and overlap joints. The results will help design process in different situation. It is worthy to know that Excessive welding heat input of any high load may cause the peak load and energy absorption capability significantly reduce. Maladjustment of the process parameter may cause change in pullout failure location from base metal to weld nugget edge due to severe indentation.corrosion Resistance of aluminumalloy H20 is very good. Besides, its strength is quite satisfactory. Aluminumalloy H20 widely used by different industries like structural and platform manufacturing. Aluminumalloy H20 machinability is excellent with a good control in grain structure .these characteristics make aluminumalloy H20 excellent for FSW process Aluminumalloy H20 a medium Strength alloy with excellent corrosion Resistance. Alloy H20 is known as a structural alloy. In plate form, H20 is the alloy most commonly used for machining. As a relatively new alloy, the higher strength of H20 has seen it replace 6061 in many applications. The addition of a large amount of manganese controls the Grain structure which in turn results in a stronger alloy. It is difficult to produce thin walled, complicated extrusion shapes. The extruded surface finish is not as smooth as other similar strength alloys. In the T4 and T6 temper, alloy H20 machines well and produce tight coils of swarf when chip breakers are used .
Abstract- Frictionstirwelding is a solid state welding process where in two materials are joined without melting the material. The process is well suited for non ferrous materials such as aluminum, copper, magnesium, zinc etc. It is an effective technique for joining dissimilar metal and alloys and finds its application in various fields such as aerospace and automotive industries. In this attempt is made to join aluminumalloy AA 7075 T651 and AA 6061T6 condition by frictionstirwelding technique under different process parameters such as tool rotation speed (750 rpm to 1250 rpm), welding speed (90 mm/min to 110 min) and using five different tools pin profiles –threaded cylindrical (TC), triangular profile (TP), conical profile (CP), square profile (SP) and hexagonal profile (HP). The outcome of the experimentation indicated that square tool pin profile and hexagonal tool pin profile at the tool rotation speed of 1250 rpm and the welding speed of 110 mm/min respectively yielded good quality welds in contrast to other tool pin profiles.
Aluminium alloys with a wide range of properties. Among all aluminum alloys, AA 6061alloy plays major role in the aerospace industry in which magnesium and silicon (0.3-1.5 w%, Si, Mg) are the principal alloying elements. Aluminum alloys 6061 is a medium to high strength heat-treatable alloy with a strength higher than 6005A. It has very good corrosion resistance and very good weldability although reduced strength in the weld zone. It is widely used in the aerospace applications because it has good formability, weldability, machinabilty, corrosion resistance, and good strength compared to other aluminum alloys.
welding process for joining metallic alloys and it is useful in serve industries for joining aluminium, magnesium and copper alloys. The various parameter such as rotational speed, transverse speed and tool tilt angle play important roles in FSW process and quality weld. The aim of this study is to know the relation between the effects of different transvers speed and tool profile on the weld quality of AA6061-T6 aluminium. The geometry of the pin tool along with the process parameters plays an important role in dictating the path that the material takes. The tool geometry was carefully chosen and fabricated to have a nearly flat welded interface pin profile. In this work, an attempt has been made to analyze the effect of various tool profiles on mechanicalproperties of aluminium alloy. Various tool profiles have been used to fabricate joints by using varying thickness work piece of Aluminium alloy. Numerical techniques particularly, the finite element method for the simulation of FSW for thermal, mechanical and thermo-mechanical modelling has been investigated. The current studies also aim to understand mechanicalproperties during the FSW.
subjected to frictionstir processing (FSP) 18) exhibits max- imum elongation more than 1250% at a temperature of 753 K and the thermal stability of ﬁne-grained microstructure developed during FSP up to 773 K. The distinction between the present results and data reported by Mishra et al. 16,17) may be resulted from diﬀerent techniques used for the develop- ment of a ﬁne-grained microstructure and experimental conditions, such as tool sizes, tool rotation and traverse speeds, phase composition, etc. These conditions may have a signiﬁcant inﬂuence on ﬁne-grained microstructure devel- oped, mechanicalproperties and thermal stability of such structure. Eﬀect of conditions mentioned above need further investigations.
The current welding technology is more diverse than ever since the different forms of products are manufactured to serve various types of industries. The choices of welding processes are also different and depend on the types of materials used, mechanicalproperties as well as the specimens for being welded. During the past 4 decades, solid state welding technique has been widely used , especially frictionstirwelding . This interesting welding provides many advantages such as no filler adding, no melting, environmentally friendly process, etc . However, frictionwelding technique is also available in many ways such as frictionwelding [4-6] or frictionstir spot welding [7-9]. This interesting welding is applicable for welding parts of automobile and boat building industries. FrictionStir Spot Welding (FSSW) was originally developed by frictionstirwelding at the Welding Institute in Great Britain . The welded specimen relies on the heat derived from the friction of the surface of the specimen and tool shoulder. Then, the tool pin is employed to drag the soft heated material to be welded together. The significant variables of the FSSW are rotation welding speed, welding time and depth of plunge . Furthermore, there are also other variables such as smoothness of surface, cleanliness of weld surface or even the shape of the welding tool [13-14]. However, most of the automobile and boat building industries usually use light weight material to produce the automotive and boat components or parts. Aluminumalloy is one of raw materials employed to manufacture parts and components since its light weight, high strength and corrosion resistance. Especially, Semi Solid Metal 7075 (SSM 7075) aluminumalloy is also used in automobile and boat building industries . Thus, it is necessary to provide the best weldingalloy or steel for manufacturing the premium grade products. For the aforementioned reasons, this led to the study of the influence of some relevant variables affecting mechanicalproperties and microstructure of SSM7075 aluminumalloy by using FSSW. The parameters included mechanicalproperties (strength, shear tensile strength and hardness) as well as microstructures. Then, the results were statistically analyzed to find the relationship between microstructures and mechanicalproperties of each variable in the experiments for determining the statistical reliability for engineering work.
Frictionstirwelding (FSW), a solid-state welding process was invented and experimentally proven by Wayne Thomas and a team of his colleagues at the Welding Institute UK and patented by the TWI in 1991, emerged as a welding technique to be used in high-strength alloys that are difficult to join with conventional technique . The process was developed initially for aluminum alloys, but since then FSW was found suitable for joining a large number of materials. In aeronautics, for instance, riveting is the preferred manufacturing process for aircraft fuselage structures; nevertheless, In FSW process, a non-consumable rotating tool, consisting of a shoulder and profiled probe or pin, is forced down into the joint line under conditions where the frictional heating is sufficient to raise the temperature of the material to the range where it is plastically deformed as shown in figure. In frictionstirwelding (FSW) a rotating cylindrical, shouldered tool with a profiled probe penetrates into the material until the tool shoulder contacts with the upper surface of the plates, which are butted together as shown in
A lot of research has been already done towards understanding the effect of tool pin profiles, tool dimension and process parameters on the material flow behavior, microstructure formation and mechanicalproperties of frictionstir welded joints. Finding the most effective parameters for FSW, as well as realizing their influence on the weld properties, has been the major topics for researchers [7-10].
 M. I. Costa, D. Verdera, C. Leitão, D. M. Rodrigues, Dissimilar frictionstir lap welding of AA 5754-H22/AA 6082-T6 aluminium alloys: Influence of material properties and tool geometry on weld strength, Materials & Design, Vol. 87, No. 11, pp. 721-731, 2015.  B. Li, Z. Zhang, Y. Shen, W. Hu, L. Luo, Dissimilar frictionstir
researchers. Therefore, the following papers followed the same investigation for frication stirwelding characterizations, At, (2003), Y. J. Chao et al. , investigated the heat transfer between the tool and the well through frication stirwelding. The investigation included the experimental and numerical techniques, by using finite element method, the heat generation due to frictionstirwelding are evaluated. The results showed that the heat flow with 5% through the tool and 95% flow through the work-piece. Also, H. J. Liu et Al, , presented evaluating of mechanical tensile properties for fracture location of frictionstirwelding of aluminumalloy types (2017-T351). The mechanical tensile properties for fracture joint are evaluated by using experimental techniques, where, the tensile properties are calculated with various parameters to investigate the effect of frictionstir processing. In addition, the results showed that the maximum properties for frictionstirwelding joint obtained at frication stir processing with parameters as, 0.07 mm/rev pitch, 100 mm/min welding speed, and 1500 rpm rotation speed.
manufacturing. In this work, semi solid metal was obtained from a new Rheo casting technique called Gas Induced semi-solid (GISS) [1,2]. It was clear that the joint between cast Al alloy has increasingly expanded in the usage of casting component in automotive such as suspension, driveline and engine parts. Conventional fusion welding of SSM aluminium die casting alloys is generally difficult due to the formation of blowholes in weld. In addition, the microstructure is also altered [3,4]. Therefore, a new welding method is required to overcome these problems. In recent year, frictionstirwelding (FSW) was developed as a solid conditions joining process in which materials are joined by the frictional heat . This process is effective for the welding of aluminium alloys. However, only a limited number of studies have been carried out on SSM cast aluminium alloys. In the case of conventional A356 alloys, the mechanicalproperties of the joints are improved in comparison to the base metal . Another study of ADC12  shows that the stir zone is comprised of a fine recrystallized zone without dendritic structure. Previous studies also reveal that the strength of frictionstir welds mainly depend on the heat treatment condition before and after joining [3,6,7,8,9,10]. The aim of this work is to evaluate the effect that FSW has on the mechanicalproperties of the SSM 6061alloy in as cast and heat treated condition. Microstructure, hardness and tensile properties of the weld joint have been studied and the results are reported.
of joints of AA6061 and AA7075 are investigated. The tensile strength of the dissimilar joints increases with decreasing heat input. When welding was conducted at highest welding speed and AA6061 Al plates were fixed on advancing side, the high strength of the joint was observed. The joints were failed at positions in HAZ on AA6061 side where the minimum hardness is located and observed that very good tensile strength and ductility. The tool process parameter plays a significant effect on the micro structural evolution . The tools used for FSW of aluminium alloys are straight, cylindrical, taper, triangular made of HSS . The process parameters can influence the frictionstirwelding joint quality such as welding speed, rotational speed, tilt angle, vertical downward force applied between the tool shoulder and the surface of the work piece . The CNC operated Milling machine suited for frictionstirwelding process at low cost for joining heat treatable aluminium alloys for aerospace and automobile industries. A detailed review is given on how to convert a conventional milling machine into a CNC milling machine to perform the Frictionstirwelding. To join a couple of 3-mm thick AA2219 and designed suitable tool and analysed the performance of welded joint. They concluded that the tool profile plays an important role of frictionstir welding.The load bearing capacity of tool pin of L80 steel and AA7075 alloy and used a three dimensional heat transfer and visco-plastic model to observe the influence of pin length and diameter on traverse force during FSW. With increase in pin length the total traverse force increases significantly .
In this study, the effect of rotational speed and traverse speed on the micro – and macrostructure, and mechanicalproperties (tensile and microhardness properties) of frictionstir butt-welded 6061-T6 aluminium alloy has been investigated. A number of research studies have been conducted on frictionstirwelding 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.