In the present experimental study, dissimilar aluminum alloy AA5083 and AA6082 were frictionstirwelded by varying toolshape, welding speed and rotary speed of the tool in order to investigate the effect of varying toolshape and weldingparameters on the mechanicalproperties as well as microstructure. The frictionstirwelding (FSW) process parameters have great influence on heat input per unit length of weld. The outcomes of experimental study prove that mechanicalproperties increases with decreasing welding speed. Furthermore mechanicalproperties were also found to improve as the rotary speed increases and the same phenomenon was found to happen while using straight cylindrical threaded pin profile tool. The microstructure of the dissimilar joints revealed that at low welding speeds, the improved material mixing was observed. The similar phenomenon was found to happen at higher rotational speeds using straight cylindrical threaded tool.
process. In particular, it can be used to join high-strength aerospace aluminum and other metallic alloys that are hard to weld by conventional fusion welding. It was performed on 4mm thickness Al6061 and Al5083 dissimilar Aluminum alloys. Aluminum alloy light weight, softer, tendency to bend easily, cost effective in terms of energy requirements so aluminum alloy has selected in this FSW technique. In this welding when two metals are joined with the help of heat generated by rubbing metals against each other. The frictionstirwelding is mostly used for joining aluminum alloys. The main defects occurring in this welding are holes, material flow rate. These defects are mainly caused due to improper selection of weldingparameters. In this project the mechanicalproperties of FSW dissimilar aluminum alloy Al5083 and Al6061 has tested with the help of universal testing machine, hardness testing by Vickers hardness at various zones of the welded joints. In this experimental the testing of mechanicalproperties based on the input parameters such as rotational speed, welding speed and offset angle with proper weldingparameters. Finally, the experimental results will be compared with microstructures are analyzed by optical microscope.
Rolled plates of AA2519-T87 aluminium alloy were used as the parent material in this investigation. The chemical composition of the parent metal was quantified using spectro-chemical analysis, and the composition is pre- sented in Table 1. The joint configuration of 150 × 150 × 6 mm was used, and the welding was done normal to the rolling direction using the tools with four different pin profiles, namely straight cylindrical (STC), straight threaded cylindrical (THC), taper cylindrical (TAC) and taper threaded cylindrical (TTC). The dimensions of the four pin profiles are shown in the Fig. 1. The joints were fabricated under air and water cooling mediums, and they are designated as FSW and UWFSW joints, respect- ively. The process parameters and the welding condi- tions used to in FSW and UWFSW process are presented in Table 2. These weldingparameters were se- lected based on trial experiments to attain defect free, sound joints. The specimens were extracted from the joints to test and characterize the FSW and UWFSW.
622 | P a g e effect of various weldingparameters, tool design effect, residual stresses induced during welding and optimization of weldingparameters. Liu et al. [2-4] performed FSW in immersed water condition for study of strength improvement, and it was found that rapid cooling due to presence of water provide higher strength compared to strength obtained in FSW performed in air. Lee et al.  studied mechanicalproperties related to variation in microstructure of 6061 Al alloy. Results showed that non-symmetric stir zone exist due to tilt angle of tool and compared to base metal fine and smaller grain was observed in stir zone. In TMAZ elongated grain structure were observed and in HAZ was found to have similar grain size as that of BM. Vijayan et al.  performed multi-objective optimization of FSW process parameter using Taguchi based grey relational analysis. Objective of their study was to find optimum level of process parameter which will result in maximization of tensile strength with minimum power consumption. Based on grey relational analysis optimum process parameter obtained was rotational speed of 650 rpm, welding speed of 115 mm/min and axial load of 9 kN respectively. Kadaganchi et al.  performed optimization of process parameter of frictionstirwelding of AA 2014-T6 using Response surface methodology. The considered process parameter spindle speed, welding speed, tilt angle and tool pin profile and response were yield strength, tensile strength and % elongation. The result showed that FSW with hexagonal tool pin profile results in maximum tensile strength and elongation and increasing tilt angle results in better material flow under shoulder and will increase mechanicalproperties of joint. Joint fabricated with welding speed of 800 mm/min, rotational speed of 1000 rpm, tilt angel of 3.5° with hexagonal pin profile will have superior tensile strength. Sahu et al.  performed multi-response optimization of process parameter in frictionstirwelding of AM20 magnesium alloy using Taguchi grey relational analysis. Selected process parameters were welding speed, rotational speed, shoulder diameter and plunging depth. L18 orthogonal array were based on Taguchi method was considered. Grey relational analysis was used for ranking of process parameter. ANOVA was used to get percentage influence of each process parameter on quality of weld.
Abstract: Aluminum alloy Al 2024-T3 were successfully joined using frictionstir spot jwelding joining (FSSW). Satisfactory joint strengths were obtained at different weldingparameters (tool rotational speed, tool plunge depth, dwell time) and tool pin profile (straight cylindrical, triangular and tapered cylindrical). Resulting joints were welded with welded zone. The different tools significantly influenced the evolution on the stir zone in the welds. Lap-shear tests were carried out to find the weld strength. Weld cross section appearance observations were also done. The macrostructure shows that the weldingparameters have a determinant effect on the weld strength (x: the nugget thickness, y: the thickness of the upper sheet and SZ: stir zone). The main fracture mode was pull out fracture modes in the tensile shear test of joints. The results of tensile shear tests showed that the tensile-shear load increased with increasing rotational speed in the shoulder penetration depth of 0.2 mm. Failure joints were obrerved in the weld high shoulder penetration depth and insufficient tool rotation.
Dissimilar aluminum alloys AA2024-T365 and AA5083-H111 were welded by frictionstir process. Weldingparameters such as tool rotational speed (900, 1120 and 1400 rpm), weld speeds (16, 40 and 80 mm/min) and tool pin pro- files (square, triangular and stepped) were used to weld many joints to study their effect on the mechanicalproperties of the joint. Also, different locations of the material were studied as other parameter. The mechanicalproperties were evaluated using tensile and hardness tests. The microstructure characte- rization of the processed alloys was carried out using optical microscopy. Ma- cro and microstructures of parent and welded specimens indicated that the weld parameters have a significant effect on mechanical and microstructural properties of the welds. However, defect-free as well as higher strength was obtained at higher speed of 80 mm/min.
Method/Analysis: The present paper discusses the process parameters followed by mechanicalproperties and microstructures which affect the weld strength. Findings: Mechanicalproperties-Tensile strength attained with different process parameters and Microstructures are obtained by Optical Metallurgical Microscopy (MET SCOPE-1) and a Scanning Electron Microscopy equipped with an X-radiation detector EDS Conclusion/Application: In this study Similar FSW between Al 6061 to Al 6061 plates with thickness 6mm were performed. The future research will contain creep tests and microstructural investigations using aluminium 6061 alloy using TEM microscopy (Transmission Electron Microscopy).It is demonstrated that FSW of aluminium to aluminiumalloys is becoming an emerging technology with numerous commercial applications. Keywords— FSW; Aluminium alloy, Mechanicalproperties, Microstructures, SEM.
4. P. Cavaliere, A. Squillace, F. Panella. In this paper the effect of welding speed (with advancing speed in the range 40– 460mm/min) on the mechanical and micro structural properties of AA6082 was studied. A strong variation in the nugget mean grain size was observed by increasing the advancing speed from 40 to 165mm/min up to a plateau corresponding to no further variations by increasing the speed up to 460 mm/min. The yield strength was recorded to increase strongly from the lower speeds to115mm/min and after it starts to decrease by increasing the advancing speed. The ductility of the material followed the same behaviour but restarted to increase after 165 mm/min. The material welded with the advancing speed of 115mm/min exhibited the best fatigue properties and the higher fatigue limit and the SEM observations of the fatigue specimens showed that at higher stress amplitude levels the cracks initiate at the surface of the welds.
The joining of dissimilar AA2024 and AA5056 aluminium plates of 5mm thickness was carried out by frictionstirwelding (FSW) technique. By using statical approach Optimum process parameters were obtained for joining two different material. To analyse the influence of rotation speed and traverse speed over the microstructural and tensile properties Five different tool designs have been used. By using FSW technique, the process of joining of the base material, well below it’s melting temperature, has opened up new trends in producing efficient dissimilar joints. Analysis of welding speed on microstructures, hardness distribution and tensile properties of the welded joints were done. By changing the parameters of different process, defect free and high efficiency welded joints were produced. Keyword: FSW , Welding, Dissimilar Metals.
Figure 3 shows photos of the samples produced at different welding speeds, in which the UFGed 1050 Al and 6061-T6 Al alloys were placed on the RS and AS, respectively. The welding was successfully done at the wide revolutionary pitches from 0.5 to 1.25 mm/rev and no obvious defects could be observed based on the appearance of the joints as shown in Figure 3a,b. However, it was found that at a larger revolutionary pitch of speed of 1 or 1.25 mm/rev, the width of the welding seam became smaller and smaller with the increasing welding distance. It was proposed that the heat input was not sufficient at the higher welding speed during welding process, and the rotating tool could not penetrate deep enough to make the tool shoulder touch the sample surface completely. As a result, a lack of contact between the tool shoulder and the surface of the work-piece was formed, as shown by the arrow in Figure 3d. Due to the very different material flow of the two materials, the interface could still be observed on the surface of the joint centerline. At the lower revolutionary pitch of less than 0.75 mm/rev, the welding process became very stable and a homogeneous welding seam was obtained, except that a slightly more flash formed on the retreating side of the joint welded at a revolutionary pitch of 0.5 mm/rev. It was revealed that the FSW of dissimilar aluminum alloys should be conducted with suitable locations and in this study the UFGed aluminum plates should be put on the RS.
This investigation highlights the influence of rotational speed of the tool, and the effect of position of the interface with respect to the tool axis on tensile strength of the frictionstir spot welded joint. The axial load is constant between the tool shoulder and the surface of the base material. The rotational speed of the tool axis is continuously changed by keeping the axial load constant. It is found that there is an optimal axial load, above which the weld is defect-free, with joint efficiency of 84% for Al alloy generally. There is a tolerance for interface position; i.e., the tool can be allowed to deviate away from the interface without deteriorating joint efficiency of the weld. The tool can be allowed to deviate from the interface in either side, but the tolerance is higher when the interface is located in the around the tool.
compared to conventional welding methods, FSW consumes considerably less energy, no consumables such as a cover gas or flux, and produces no harmful emissions during welding, thereby making the process environmentally friendly . Further, because FSW does not involve the use of filler metal and since there is no melting, any aluminium alloy can be joined without concern for compatibility of composition or solidification cracking issues associated with fusion welding. Also, dissimilaraluminiumalloys and composites can be joined with equal ease . The FSW basically uses a non-consumable rotating tool with a specially designed pin; and for the welding, shoulder is inserted into abutting edges of
943 | P a g e method like Gas metal Are welding. The quality of the weld in FSW is determined by the process parameterstool rotation speed, tool traverse speed and plunge speed, depth of tool penetration and axial force on the shoulder  –. Quality weld can be obtained by precise control of these above parameters. Mechanicalproperties in weld zone are affected by frictionstir processing due to the rotation of the tool .
Friction between the tool and the work piece is accomplished by heating which results in work piece of plate to undergo plasticdeformation . The localized heating tempers the material to be semi solid state around the pin and movement of material from the front of the pin to the back of the pin due to combination of tool rotation and translation. The Joint is formed in solid state at the end of this process. The mechanical performance of the welding depends specifically on the weldingparameters such as rotational speed and traverse speed which influences welding strength of the joint [7-9]. Grain size, residual stresses, and strength of the weld influences tool deformation. Recently, many literatures have been studied to explore frictionstirweldeddissimilar Aluminum alloys and Aluminum based metal matrix composites.
The experimental joints were carried out by a WMW ECKERT vertical milling machine. A butt joint form was used. The direction of the experimental weld line is perpendicular to the rolling orientation of the sheets. The base metals were clamped and supported by a steel backing plate. The lengths of the weld were 8, 12 and 16 cm and the tool materials used were K107, W302 tool steel. These conditions were used to evaluate the ability of the tool materials to withstand heat and friction. Table 5 illustrates the values of the process variables of the experimental joints. The steel was placed on the advancing side, and the aluminum was placed on the opposite side (retreating side) in all the joints except one joint (joint 4, the steel was placed on the retreating side). A traditional type of tool cooling (by a cooling hose from outside) was applied to cool the tool, and the coolant dropped from the tool relatively cooled the weld zones. The experimental procedures and the place of the samples test of 8, 12, and 16 cm welds are given in Figure 1. The other process variables were fixed in all experimental joints: 1550 rpm rotational speed, 17 mm/min traverse speed, 0.5 mm pin offset to the steel side (0 mm offset: the pin was completely plunged in the aluminum side), 1.6 mm pin length, and 0.2 mm plunge depth. Photographs of the weld face and the weld root of the welded joints are presented in Figure A.1 (Appendix A). These values of the process parameters were obtained after many trials. During the screening of the process parameters, many surface defects were observed as shown in Figure A.2 (Appendix A). These defects relate to low generated frictional heat, high tool offset to the steel side or insufficient flow of the deformed metal.
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 aluminiumalloys 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 aluminiumalloys 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 .
The focus of the research work will be concentrated in the mechanical performance and the stir zone microstructure by FSW lap and butt welded part having 100mm × 50mm × 6mm thick sheet Aluminum (AA7075) and 100mm × 50mm × 6mm thick sheet Al 2014using constant pin diameters. All the testing of welded part will be tested by ASTM standard. Cylindrical pin tool will used to conduct experiments .
Therefore, many researchers have recently aimed to improve joint strength and reduce tool wear through FSW hybrid welding that uses a secondary laser heat source to preheat the steel side [11–16]. One instance is the study conducted by using laser assisted hybrid FSW welding (laser-HFSW) to make butt joints of dissimilar Al6016-T6 aluminum alloy and DC04 mild steel sheet at a thickness of 1 mm . Their solution was to apply the laser assistance when preheating the steel sheet, the laser positioned 10 mm toward the tool and 3 mm toward the butt joint interface. They also found that the specimen welded with a rotation speed of 2000 rpm, a welding feed of 1500 mm/min and a laser power of 1000 W
N. T. Kumbhar et. al. 2008 managed FrictionStirWelding of Al 6061 Alloy. States that during the frictionstirwelding, high deformation is observed at the nugget zone and the developed microstructure strongly influences the mechanicalproperties of the joint. FSW trials were done utilizing a vertical milling machine on Al 6061 alloy. Morteza Ghaffarpour, et. al. 2013 In his Review of Dissimilar Welds of 5083-H12 and 6061-T6 performed by FrictionStirWelding, describes that as the conventional fusion welding is undesirable for welding aluminum alloys, there are numerous works performed on the aluminum alloys by FSW. These works are considering to the effects of FSW parameters on sheet formability, weld quality after FSW, and optimization of the FSW process. S. Jannet et. al. 2013 managed Comparative research of frictionstirwelding and fusion welding of 6061-T6 and 5083-O aluminum alloy in view of microstructure and mechanicalproperties states. In this study, the mechanicalproperties of welded joints of 6061- T6 and 5083-O aluminum alloy determined utilizing frictionstirwelding (FSW) with four rotational speeds (450, 560, 710 and 900 rpm) and conventional fusion welding are investigated.
speeds, as shown in (b), (c), and (d) of Figs. 2 and 3 onion ring patterns were obviously observed in SZ irrespective to the ﬁxed locations of materials respectively. The onion ring was more clearly visible on the advancing side than retreating side. These clear visible bands on the advancing side than retreating side, which is usually appeared not only in dissimilar aluminum alloysfrictionstirwelded joints but also in similar ones. It would be rather diﬃcult to understand the formation mechanism of onion ring. Some reports 16,17) explained the reasons of onion ring formation. They suggested that the onion ring was formed as a result of the extrusion of cylindrical sheets of material per each revolution of weldingtool during its forward motion. The tool appears to