Friction Stir Welding (FSW) of Aluminum Alloys: A Review

Friction Stir Welding (FSW) of Aluminum Alloys: A Review

Preety Rani

Department of Mechanical Engineering, Delhi Technological University

Delhi, India.

R. S. Mishra

Department of Mechanical Engineering Delhi Technological University

Delhi, India.

Abstract:- The main goal of this research work is to consider and provide a complete analysis of friction stir welding on aluminum alloys undertaken by the majority of researchers. The impact of process factors on weld reactions, material flow, and microstructure is the focus of the research. FSW factors such as tool rotational speed, welding speed, shoulder diameter, tool pin diameter, and tool pin profile have a substantial impact on the micro hardness, tensile strength, yield strength, and strain rate of FSWed aluminum alloys, according to the study.

Keyword: Friction stir welding, strain rate, ultimate tensile strength, micro-hardness.

1. INTRODUCTION

   Friction-stir welding (FSW) is a solid-state method, which implies that the base metals are bonded without melting during the process, preserving the parent material's original features as much as possible after welding [1-2]. FSW is done with the assistance of a specially designed tool that consists of a shoulder of cylindrical shape and a pin of different profiles that spins and plunges into the parting line of the two-base plate. When the tool pin and the workpiece make contact, friction is created, which provides heat for welding, softening the workpiece without melting it and allowing the tool to move along the weld line under force. Intermixing of work- piece material occurs as a result of tool rotation, and work- piece plates are connected together[3].The demand for lightweight materials, particularly aluminium and its alloys in structural components, is increasing in practically all

   industries, including cars, aircraft, marine, and defence [4]. The permanent bonding of different aluminium alloys would improve structural design flexibility and increase its uses [5]. As a result, a number of fusion and solid-state welding methods have been used to examine the welding of incompatible aluminium alloys [6]. Due to the increased potential for solidification cracking, greater residual stress, intermetallics, and vaporisation of alloying elements caused by high heat input, the use of fusion welding methods in welding dissimilar aluminium alloys is limited[5].Because of its high weld quality, cheap cost, and low energy consumption, friction-stir welding (FSW) is often used to weld lighter materials including aluminium and magnesium alloys.

2. LITERATURE REVIEW

   The influence of different friction stir welding/ processing process parameters on different metals has been reviewed after a thorough study of numerous research data. This review is offered in tabular form and consists of published works on dissimilar metals. The Table A below summarizes the parameters that were considered by previous writers.

   Table 1 Literature review of aluminum alloys: –

   Sr. No.	Year	Author	Work-Piece	Tool & type of joint	Input parameters	Output parameters	Finding
   1	2003	Prado et al.	AA6061+20% Al2O3	butt joint	traverse speed and tool pin profile	Tool wear and wear rate	1) When weld or traverse speeds are increased, tool wear and the wear rate are found to decrease. [7, 8]
   2	2005	Fratini,L. and, Buffa,G.	AA 6082-T6	butt joint		strain, strain rate and temperature	1) An inverse-identification technique based on a linear regression methodology was employed to provide the required material characterization. [9].
   3	2006	Kulekci, et al.	AA5754	Lap joint	tool pin dia., and tool rotation speed	fatigue strength and microstructure	1) The fatigue strength of joints is reduced when tool rotation is increased for a fixed tool pin diameter. The fatigue strength of joints is reduced when tool pin diameter is increased for a fixed tool rotation [10].
   4	2012	Liu et al..	AA 2219-T6		non-rotational shoulder dia. And welding speed	micro structure, hardness and tensile strength	1) Microstructures and Vickers hardness distributions revealed that this novel welding method improves asymmetry and in homogeneity, particularly non the weld nugget zone. Up to 69 percent of the basic material's tensile strength was achieved [11].
   5	2007	Scialpi et al.	AA6082		shoulder geometries	transverse tensile strength, microstructure	1) According to the findings, the best joint for thin sheets was welded by a shoulder having cavity and fillet [12-15].
   6	2006	Cavalier et al.	AA2024-7075			tensile, fatigue strength,	T1) he two sheets were successfully welded one after the other, and the welded sheets were tested under strain at room temperature to

   						hardness and microstructure	determine their mechanical reaction in comparison to the parent materials [16].
   7	2012	Deplus et al.	AA 2024-T3, AA5754- H111 and AA 6082-T6	thin copper, brass and tungsten of dia. 0.05 to 0.3 mm	Machining Gap, Thermal Energy, Dilectric Pressure, Current	MRR and Surface Finish	1) The static deflection of the wire and vibrational behaviour have been reported to produce inaccuracies [17]. intelligent systems or Expert knowledge have been stated to lessen the inaccuracy due to the static deflection of the wire and vibrational behaviour.
   8	2007	Zhang et al.	AA 6061 -T6		rotation speed, axial forceand welding speed	material flow	1) There appears to be a quasi-linear relationship between the variation of the equivalent plastic strain and the variation of the applied loads on the shoulder. On increasing in the pin's translational and angular velocity, the material flow may be accelerated [18].
   9	2008	Raghu Babu, et al.	AA6082-T6	butt joint & HSS tool	rotation speed, axial force and welding speed	tensile strength, hardness and microstructure	1) The joint's tensile strength is less than that of the parent metal. And it's proportional to the speed of travel / welding [19-22].
   10	2005	Heurtier, et al.	AA2024-T351	butt joint		micro-hardness, estimations of the temperatures strains and strain rates.	1) The semi-analytical model may be employed to calculate stresses, micro-hardness, strain rates, and temperature estimates in different weld zones [23].
   11	2011	Aval et al.	AA5086		Tool rotational speed, welding speed	temperature distribution, yield & tensile effect.	1) The final microstructures and mechanical characteristics of welded alloys can be greatly influenced by work-hardened and annealed conditions [24].
   12	2016	Mehtaa et al.	AA6061-T651	tool steel of M2 grade	cylindrical, triangular, square and hexagonal Pin profile	defects
   13	2016	Zhang et al..	AA2219-T6		welding speeds,water- coolingand air- cooling conditions & artificial ageing	tensile strength andhardness	1) The ideal method to increasing the mechanical characteristics of FSW2219Al-T6 joints has been demonstrated to be a combination of post-welding artificial ageing and high welding speed, with a highest joint efficiency of 91 percent attained [26].
   14	2016	Guillo. et al.	AA5754-H22	FSWtool ofH13toolsteel	Rotationalspeed, travelingspeed, tiltangle		1) A robot with an inbuilt real-time algorithm for compensating lateral tool deviation may recreate the same FSW edquality as a gantry- type CNC system, according to this article [27].
   15	2016	Nam et al.	6061 aluminum alloy	SKD11toolconsist of a narrower probe and a columnar shape.	welding speed	Potentiodynami c and EIS studies	1) According to the findings, a high-quality thin coating on the surface with improved properties resulted in a high-corrosion-resistant alloy. This might be owing to the FSW's homogenous impurity distribution in the alloy, on which a homogeneous passive coating was generated to improve corrosion resistance [28].
   16	2009	Babu. et al.	AA2219 aluminium alloy	High carbon steel tool	rotational speed, tool pin profiles, welding speed and axial (downward) force.	Tensile strength	1) With a 95% confidence level, a mathematical model was built to estimate the tensile strength of FSWed AA2219 joints [29].
   17	2015	Dongxiao. et al.	7075-T651 aluminumallo y	Butt joint	Tool rotational speed (rpm), Welding speed (mm/min)	Microstructural characteristics, welding process,Hardne ss and tensile strength	1) Both the existence of precipitates and the displacement of component particles may be blamed for the reduced crack initiation energy in the heat affected zone (HAZ). The presence of precipitates in the HAZ was the primary cause of the SSFSW joint's lower tensile strength [30].
   18	2015	Bahemma t. et al.	AA7075-O and AA2024- T4	Threaded with four flute and threaded taper tool	Tool rotation speed,welding speed	Ultimate Tensile strength, Elongation,Har dness,yield strength,	1) The purpose of the microstructure analysis is to see how the pin profile and rotating speed affect grain size. Furthermore, one of the most important aims in the current study is to get high-quality welds with the least amount of money [31].
   19	2008	Chionopo ul et al.	5083-H111 aluminum alloy	butt joint, thermal treated steel a) Compact conical	Rotational speed, (N) and Welding speed, (S)	Microhardness, Microstructure	1)It was shown that under particular welding conditions, only the conical pin shape resulted in defect-free welds. In terms of the in the case

   1. Welds constructed using triangular pin shapes produced the most uneven and massive copper particles. Furthermore, holes, tunnels, fractures, and fragmental flaws were generated by polygonal pin profiles, regardless of their static and dynamic constant areas.

   2. Additionally, as the number of polygonal edges increased, faults reduced. The cylindrical tool pin profile has been reported to have a defect-free macro joint [25].

   				pin tool, b) Screw type pin head.			of screw type pins, these first studies resulted in defective welds, most likely owing to the screw's unique design or the welding settings used, which were not ideal. 2)Micro-hardness measurements were made on specimen cross sections and associated with the establishment of FSP zones. The ideal parameters matched to welding zones that were free of flaws and other interruptions. In any event, the welding instrument suffered no damage as a result of the procedure [32].
   20	1999	Mishra et al.	AA 7075-T6	Single pass FSPed zone of 0.3 m length	traverse speed of 15 cm/min.	Strain rate, Tensile tests	1) The current findings show that friction stir processing may be used to create a microstructure in a commercial aluminum alloy that is susceptible to high strain rate superplasticity [33].
   21	2011	García- Bernal et al.	AA 5083 produced by continuous strip casting with different Mn	FSP tool of MP159 alloy.Mn and Cr dispersoid formers	rotation rate -400 rpm and 0.42 mm/s traverse speed	Strain rate	1) Increased Mn concentration increases ultimate and yield strength. The two alloys with the lowest Mn concentration had the highest elongation values (almost 800 percent) [34].
   22		DANAF et al.	AA5083, 3 mm thickness	H13 tool steel tool was used	rotational speeds – 430 and 850 rpm and traverse speed -90 mm/min	Tensile tests andstrain rates	I) The attributes of the DRX refined microstructure achieved in the 43990 FSP condition were far better to those of the 85090 FSP condition.
   23	2012	Kandasam y.J, and Rajesham. S.,	6mm thick AA7075 and AA6061	High speed steel toolwith 10% cobalt		Yield strength Tensile strengt %Elongation Hardness Shear strength Distribution Vickers micro hardness across the weld line
   24	2010	Suresha. et al.	AA7075-T6 of 5mm thickness	square butt joints. Nonconsumable tools made of hot die steel	4.99 mm)	Tensile strength, joint efficiency
   25	2015	Amini.S., and Amiri.M.,	friction stir welding on aluminum 5083with dimensions of 120 mm×60 mm×4 mm.	Four tools of AISIH13 with 1)shoulder dia.-18 mm, Different shapes of tool pin were used	(63,100 mm/min)	vertical force and welding force	1) The impact of an offset pin on vertical force and welding force reduction (between 50 and 70 percent) is larger than the impact of a concentric pin with the tool shoulder axis on these forces. 2) Tools with a half pin and an arching pin exert greater force than tools with an offset pin, but less force than tools with a concentric pin [38].
   26		Scialpi. et al.	AA 6082 T6	The tool made of 56NiCrMoV7-KU. The tool with pin 1.7 mm dia. and 1.2 mm height.		Mechanicaland Microstructural properties

   1. Demonstrated that reducing grain size increased ductility and reduced forming loads considerably.

   2. The presence of a rather high strain rate sensitivity shows that superplastic deformation is operating under these experimental conditions [35].

   1. Shoulder dia. (16mm)

   2. threaded Pin dia (6mm)

   3. length (5.8mm)

   1. Tool rotational speed (1400rpm)

   2. traverse speed (16mm/min)

   3. Axial force (6kN)

   1. The goal of the experiment is to reduce the temperature difference between bottom surfaces and the top of the plates as much as possible..

   2. The creation of Al2Cu and Al4Cu9 IMCs increases bond strength, according to analysis of the generated intermetallic compound (IMC)[36].

   1. Square tool

   2. conical tool

   1. Tool rotational speed (900,1120,1400RP M)

   2. Welding speed (40,50 and 63mm/min)

   3. Plunge depth (4.93,4.96 and

   1. The welded joints of the conical tool are more efficient than those of the square tool.

   2. ANOVA was used to determine the percentage contribution of these FSW process parameters, and it was observed that tool rotating speed, when compared to weld traverse speed and plunge depth, has a substantial contribution in both conical and square tools [37].

   1. pin dia.- 5.5 mm,

   2. angle – 9°

   3. pin height – 3.85 mm

   1. Rotational speed – (560,900,1120,140 0rpm)

   2. Translational speed-

   3. Tool tilt angle – (1.5°)

   1. Tool rotation speed – 1810 rpm

   2. traverse speed – 460 mm/min) tilt angle 2 & 0.1 mm plunge Shoulders with three different features1. scroll (TFS)2. cavity (TFC)3. fillet (TF)

   1. A study of three shoulder geometries was conducted in this study. The tool analysis was performed on 1.5 mm thick AA 6082 T6 sheets. The tool was rotated at 1810 rpm with a federate of 460 mm/min during the welding operation.

   2. The analysis revealed that the optimum junction for thin sheets was welded by a shoulder with fillet and cavity [39].

   27		Mastanaia h. et al	AA2219-T6 Al-Cu alloy and AA5083.	Squar- butt joint	-1, 0, 1 ,2mm)
   28	2007	Johannes et al	AA5083.	High strength cobalt alloy (MP159) tool. shoulder – 25 mm Tool pin length – 6.4 mm.	25.4 mm/min	Microstructure examination Tensile testing	1) By modifying the size and distribution of component particles before to cold rolling, FSP assists in the reduction of post-recrystallization grain size. It was discovered that adding the FSP stage refined the recrystallized grain size, decreased flow stresses and enhanced elongations [41].
   29	2012	Magdy. M. E. and Ehab A. E.,	AA- 6082- T651 plates , 6mm thick	Tool material Mo W tool steel	mm /min	1) Microstructural characteristics	1) The results of the hardness and tensile tests showed that increasing the number of passes resulted in softening and a decrease in UTS, but increasing traverse speed enhanced strength and hardness. 2). Multiple passes resulted in increased grain size, precipitate dissolution, and fragmentation of second phase particles due to the accumulated heat.[42].
   30	2014	Deepati,et al.	AA5083 and AA1100(T- 6- mm)	Tool made of H-13 tool steel 2) Straight &tapered cylindrical pin tool	RPM
   31	2012	Klobcar.D ., et al.	AA 5083 (T- 4-mm)	Tool made of EN 42CrMo4 steel. FSW tool geometry was used with a threaded pin	to 1250 r/min mm/min	1) Microstructure	1) The microstructure was prepared for examination under a polarized light source using a light microscope. At an FPR of 0.35 mm/r, a set of ideal welding conditions was identified, allowing excellent welds to be formed with a small improvement in hardness and a 15% reduction in tensile strength [44].
   32	2012	Jerome.S. et al	AA5083 /TiC particles	Tool made of EN 31 steelShoulder Dia.- 18 mm, Pin Dia. and length 6 mm and 2 mm, respectively	1) Tool Rotation Speed- 710,900,1120,140 0 Rpm2) Traverse Speed – 16mm/min	1) Microstructural Observations.2) Microhardness Details	1) The microhardness profiles of the treated samples were assessed along the top surface and across the cross section. When compared to the base metal (88Hv), the average hardness along the top surface increased by 27.27 percent [45].
   33	2014	Krishna et al	AA6351 and AA5083	High speed steel (HSS)	Feed rate – 20 mm/min 1) Rotational speed – 1000, 1100,1200,1300,1 400,1500 RPM	Yield strength, Tensile strength and % elongation

   1. Rotation speed (400,800,1200,160 0,2000 rpm)

   2. Tool traverse speed (30 210 390 570 750 mm/min)

   3. Tool offset from joint line (-2,

   1. % El.

   2. Joint efficiency on UTS

   3. Failure location

   1. Using diverse methods such as macrostructural analysis and electron probe micro analysis, the impacts of process parameters and tool-offset on the degree of material intermixing and to reduce percent area of volumetric defects were investigated in detail.

   2. It is well established that the tool offset and welding settings have the greatest impact on the nugget zone mixing pattern and subsequent joint strength [40].

   1. Rotational rate – 600 rpm

   2. traverse speed –

   1. Tool rotational speed – 850 rpm

   2. Transverse speed- 90,140,224

   1. Second phase particles

   2. Mechanical characteristics

   1. Tool-rotation speed – 1000,1400

   2. welding speed – 56,80 mm/min

   1. Hardness

   2. Tensile Test

   1. Tool geometries have a substantial impact on dissimilar material FSW weld quality. In the case of taper cylindrical tools with the same process parameter, both hardness and tensile strength were greater.

   2. In dissimilar friction stir weldments, lower traverse rates combined with greater rotating speeds produce the highest tensile characteristics [43].

   1. tool-rotation speed -200 r/min

   2. welding speed – 71 mm/min to 450

   1. Hardness

   2. Tensile properties

   1. Describes the effect of an FSW process including butt joining of identical AA6351 and AA6351 combinations and dissimilar AA6351 and AA5083 combinations on tensile, hardness, and impact behaviour.

   2. When compared to different alloy combinations, the tensile, hardness, and impact characteristics of Aluminum alloys of comparable alloy combinations show better results [46-49].

3. CONCLUSION

The results of this investigation showed the proces factors employed during the welding of several aluminum alloys, as well as the impact of those parameters on the weld reactions. Process factors such as rotating speed, weld speed, tool pin shape, tool tilt angle, tool offset, and others were shown to have a substantial impact on the weld quality of friction stir welded aluminum alloys. The following findings may be taken from the preceding research.

1. In compared to different aluminum alloy combinations, comparable aluminum alloy combinations have higher tensile strength, hardness, and impact strength.

2. The final microstructures and mechanical characteristics of welded AA5083 alloy can be greatly influenced by work- hardened and annealed conditions.

3. The creation of Al2Cu and Al4Cu9 IMCs by the interaction of AA6061 and AA7075 with copper in coating form increases bond strength, according to analysis of the generated intermetallic compound (IMC).

4. ANOVA was used to evaluate the % contribution of these FSW process factors, and it was discovered that in the case of both square and conical tools during welding AA7075, tool rotating speed has a significant contribution compared to weld plunge depth and traverse speed.

REFERENCES

[1] Husain Mehdi & R. S. Mishra (2021) Consequence of reinforced SiC particles on microstructural and mechanical properties of AA6061 surface composites by multi-pass FSP, Journal of Adhesion Science and Technology, DOI: 10.1080/01694243.2021.1964846.

[2] Mehdi H, Mishra R. Microstructure and mechanical characterization of tungsten inert gas-welded joint of AA6061 and AA7075 by friction stir processing. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications. 2021;235(11):2531-2546. doi:10.1177/14644207211007882

[3] Mehdi, H., Mishra, R.S. Effect of Friction Stir Processing on Mechanical Properties and Wear Resistance of Tungsten Inert Gas Welded Joint of Dissimilar Aluminum Alloys. J. of Materi Eng and Perform 30, 19261937 (2021). https://doi.org/10.1007/s11665- 021-05549-y.

[4] Mehdi, H., Mishra, R.S. Influence of Friction Stir Processing on Weld Temperature Distribution and Mechanical Properties of TIG- Welded Joint of AA6061 and AA7075. Trans Indian Inst Met 73, 17731788 (2020). https://doi.org/10.1007/s12666-020- 01994-w

[5] Mehdi, H., & Mishra, R. S. (2020). Effect of friction stir processing on mechanical properties and heat transfer of TIG welded joint of AA6061 and AA7075. Defence Technology. doi:10.1016/j.dt.2020.04.014.

[6] Mehdi, H., & Mishra, R. S. (2018). Analysis of Material Flow and Heat Transfer in Reverse Dual Rotation Friction Stir Welding: A Review. International Journal of Steel Structures. doi:10.1007/s13296-018-0131-x.

[7] Prado, R.A., Murr, L.E., Soto, K.F. & McClure, J.C. (2002). Self- optimization in tool wear for friction-stir welding of Al 6061_/20% Al2O3 MMC. Materials Science and Engineering ,A, 349, (2003), 156-/165.

[8] Fratini, L., Buffa, G. (2004). CDRX modelling in friction stir welding of aluminium alloys. International Journal of Machine Tools & Manufacture, 45, (2005), 11881194.

[9] Kulekci, M.K.,Sik,A., Kaluc,E. (2006). Effects of tool rotation and pin diameter on fatigue properties of friction stir welded lap joints. Int J Adv Manuf Technol, (2008), 36,877882.

[10] Jamshidi Aval, H., Serajzadeh, S. & Kokabi, A.H. Experimental and theoretical evaluations of thermal histories and residual stresses in dissimilar friction stir welding of AA5086-AA6061. Int J Adv Manuf Technol 61, 149160 (2012). https://doi.org/10.1007/s00170-011-3713-8.

[11] Scialpi,A., De Filippis,L.A.C., Cavaliere,P.(2006). Influence of shoulder geometry on microstructure and mechanical properties of friction stir welded 6082 aluminium alloy. Materials and Design, 28,(2007),11241129.

[12] Mehdi, Husain; Mishra, R. S. (2020). Effect of Friction Stir Processing on Microstructure and Mechanical Properties of TIG Welded Joint of AA6061 and AA7075. Metallography, Microstructure, and Analysis, (), . doi:10.1007/s13632-020- 00640-7

[13] Mehdi, Husain; Mishra, R.S. (2020). Investigation of mechanical properties and heat transfer of welded joint of AA6061 and AA7075 using TIG+FSP welding approach. Journal of Advanced Joining Processes, 1(), 100003. doi:10.1016/j.jajp.2020.100003

[14] Mehdi, Husain; Mishra, R. S. (2019). Study of the influence of friction stir processing on tungsten inert gas welding of different aluminum alloy. SN Applied Sciences, 1(7), 712

. doi:10.1007/s42452-019-0712-0

[15] Cavalier,P., Nobile,R., Panella, F.W.& Squillace, A. (2005). Mechanical and microstructural behaviour of 20247075 aluminium alloy sheets joined by friction stir welding. International Journal of Machine Tools & Manufacture , 46, (2006), 588594.

[16] Deplus, K., Simar, A., Haver, W.V. et al. Residual stresses in aluminium alloy friction stir welds. Int J Adv Manuf Technol 56, 493504 (2011). https://doi.org/10.1007/s00170-011-

3210-0.

[17] Zhang, H., Zhang, Z., Chen, J. (2006). 3D modeling of material flow in friction stir welding under different process parameters. Journal of Materials Processing Technology, 183, 6270.

[18] Raghu Babu, G., Murti, K.G.K., Janardhana, G.R. (2008). An Experimental Study On The Effect Of Welding Parameters On Mechanical And Microstructural Properties Of Aa 6082-T6 Friction Stir Welded Butt Joints. Asian Research Publishing Network (Arpn), 3, 5, 1819-6608.

[19] Mehdi, Husain; Mishra, R.S. (2020). An experimental analysis and optimization of process parameters of AA6061 and AA7075 welded joint by TIG+FSP welding using RSM. Advances in Materials and Processing Technologies, (), 1 23. doi:10.1080/2374068X.2020.1829952

[20] Husain Mehdi, Arshad Mehmood, Ajay Chinchkar, Abdul Wahab Hashmi, Chandrabhanu Malla, Prabhujit Mohapatra. Optimization of process parameters on the mechanical properties of AA6061/Al2O3 nanocomposites fabricated by multi-pass friction stir processing, Materials Today: Proceedings,2021, https://doi.org/10.1016/j.matpr.2021.11.333.

[21] Nait Salah, Husain Mehdi, Arshad Mehmood, Abdul Wahab Hashmi, Chandrabhanu Malla, Ravi Kumar, Optimization of process parameters of friction stir welded joints of dissimilar aluminum alloys AA3003 and AA6061 by RSM, Materials Today: Proceedings,2021, https://doi.org/10.1016/j.matpr.2021.10.288.

[22] Heurtier,H., Jones, M.J., Desrayaud, C., Driver, J.H., Montheillet,F.& Allehaux,D. (2005). Mechanical and thermal modelling of Friction Stir Welding. Journal of Materials Processing Technology, 171, (2006), 348357.

[23] Jamshidi Aval, Hamed & Serajzadeh, S. & Kokabi, Amir Hossein. (2011). Theoretical and experimental investigation into friction stir welding of AA 5086. The International Journal of Advanced Manufacturing Technology. 52. 531-544. 10.1007/s00170-010- 2752-x.

[24] Mehta, Kush. (2016). Effects of Tool Pin Design on Formation of Defects in Dissimilar Friction Stir Welding. Procedia Technology. 23. 513-518. 10.1016/j.protcy.2016.03.057.

[25] Z. Zhang, B.L. Xiao, Z.Y. Ma, Enhancing mechanical properties of friction stir welded 2219Al-T6 joints at high welding speed through water cooling and post-welding artificial ageing, Materials Characterization, Volume 106, 2015, 255-265.

[26] Mario Guillo, Laurent Dubourg, Impact & improvement of tool deviation in friction stir welding: Weld quality & real-time compensation on an industrial robot, Robotics and Computer- Integrated Manufacturing, Volume 39, 2016, Pages 22-31.

[27] Nam, N.D. & Le, Dai & Mathesh, Motilal & Bian, M.Z. & Thu, Vu. (2016). Role of friction stir welding Traveling speed in enhancing the corrosion resistance of aluminum alloy. Materials Chemistry and Physics. 173. 10.1016/j.matchemphys.2016.02.004.

[28] Babu, S., Elangovan, K., Balasubramanian, V. et al. Optimizing friction stir welding parameters to maximize tensile strengt of AA2219 aluminum alloy joints. Met. Mater. Int. 15, 321330 (2009). https://doi.org/10.1007/s12540-009-0321-3.

[29] Rambabu, Gundla & Naik, D. & Ch, Venkata & Rao, K. & Reddy, G.. (2015). Optimization of Friction Stir Welding Parameters for Improved Corrosion Resistance of AA2219 Aluminum Alloy Joints. Defence Technology. 53. 10.1016/j.dt.2015.05.003.

[30] Dongxiao Li, Xinqi Yang, Lei Cui, Fangzhou He, Xu Zhang, Investigation of stationary shoulder friction stir welding of aluminum alloy 7075-T651, Journal of Materials Processing Technology, Volume 222, 2015, Pages 391-398.

[31] Bahemmat, Pouya & Haghpanahi, Mohammad & Besharati Givi, Mohammad Kazem & Reshad Seighalani, Kambiz. (2012). Study on dissimilar friction stir butt welding of AA7075-O and AA2024- T4 considering the manufacturing limitation. International Journal of Advanced Manufacturing Technology – INT J ADV MANUF TECHNOL. 59. 10.1007/s00170-011-3547-4.

[32] Mishra, R S, Mahoney, M W, McFaden, S X, Mara, N A, and Mukherjee, A K. High strain rate superplasticity in a friction stir processed 7075 Al alloy. United States: N. p., 1999. Web. doi:10.1016/S1359-6462(99)00329-2.

[33] M.A. García-Bernal, R.S. Mishra, R. Verma, D. Hernández-Silva, Hot deformation behavior of friction-stir processed strip-cast 5083 aluminum alloys with different Mn contents, Materials Science and Engineering: A, Volume 534, 2012, Pages 186-192.

[34] El-Danaf, Ehab & El Rayes, Magdy & Soliman, Mahmoud. (2011). Low temperature enhanced ductility of friction stir processed 5083

aluminum alloy. Bulletin of Materials Science. 34. 10.1007/s12034- 011-0341-8.

[35] Hector, Louis & Chen, Yen-Lung & Agarwal, Sumit & Briant, Clyde. (2007). Friction Stir Processed AA5182-O and AA6111-T4 Aluminum Alloys. Part 2: Tensile Properties and Strain Field Evolution. Journal of Materials Engineering and Performance. 16. 404-417. 10.1007/s11665-007-9060-0.

[36] J. Kandasamy, M. Manzoor Hussain & S. Rajesham (2012) Heterogeneous Friction Stir Welding: Improved Properties in Dissimilar Aluminum Alloy Joints through Insertion of Copper Coupled with External Heating, Materials and Manufacturing Processes, 27:12, 1429-

1436, DOI: 10.1080/10426914.2012.709340.

[37] C. N. Suresha, B. M. Rajaprakash & Sarala Upadhya (2011) A Study of the Effect of Tool Pin Profiles on Tensile Strength of Welded Joints Produced Using Friction Stir Welding Process, Materials and Manufacturing Processes, 26:9, 1111-1116.

[38] Amini, S. & Amiri, Mohsen. (2015). Pin axis effects on forces in friction stir welding process. The International Journal of Advanced Manufacturing Technology. 78. 10.1007/s00170-015-6785-z.

[39] Scialpi, Agostino & De Filippis, Luigi & Cavaliere, P.. (2007). Influence of shoulder geometry on microstructure and mechanical properties of friction stir welded 6082 aluminium alloy. Materials

& Design. 28. 1124-1129. 10.1016/j.matdes.2006.01.031.

[40] P., Mastanaiah & Sharma, Abhay & Reddy, G.. (2015). Dissimilar Friction Stir Welds in AA2219-AA5083 Aluminium Alloys: Effect of Process Parameters on Material Inter-Mixing, Defect Formation, and Mechanical Properties. Transactions of the Indian Institute of Metals. 69. 10.1007/s12666-015-0694-6.

[41] Johannes, L.B. & Charit, Indrajit & Mishra, Rajiv & Verma, Ravi. (2007). Enhanced superplasticity through friction stir processing in continuous cast AA5083 aluminum. Materials Science and Engineering A-structural Materials Properties Microstructure and Processing – MATER SCI ENG A-STRUCT MATER. 464. 351- 357. 10.1016/j.msea.2007.02.012.

[42] El-Danaf, Ehab & El Rayes, Magdy & Soliman, Mahmoud. (2010). Friction stir processing: An effective technique to refine grain structure and enhance ductility. Materials & Design. 31. 1231-1236. 10.1016/j.matdes.2009.09.025.

[43] Biswas, Pankaj. (2014). Experimental Investigation of Mechanical Properties on Friction Stir Welding of Dissimilar Aluminum Alloys. International Journal of Current Engineering and Technology. 2. 242-246.

[44] Klobar, Damjan & Kosec, Ladislav & Pietras, Adam & Smolej, Anton. (2012). Friction-stir welding of aluminium alloy 5083. Materiali in Tehnologije. 46. 483-488.

[45] Savarimuthu, Jerome & Bhalchandra, S & Babu, Kumaresh & Ravisankar, B. (2012). Influence of Microstructure and Experimental Parameters on Mechanical and Wear Properties of Al- TiC Surface Composite by FSP Route. Journal of Minerals and Materials Characterization and Engineering. 11. 10.4236/jmmce.2012.115035.

[46] Krishna, G.Gopala & Reddy, P.Ram & Hussain, M Manzoor. (2014). Mechanical Behaviour of Friction Stir Welding Joints of Aluminium alloy of AA6351 with AA6351 and AA6351 with AA5083. International Journal of Engineering Trends and Technology. 10. 161-165. 10.14445/22315381/IJETT-V10P231.

[47] Jain, S., Mishra, R.S. Microstructural and mechanical behavior of micro-sized SiC particles reinforced friction stir processed/welded AA7075 and AA6061. Silicon (2022). https://doi.org/10.1007/s12633-022-01716-5.

[48] Jain S, Mishra RS. Effect of Al2O3 nanoparticles on microstructure and mechanical properties of friction stir-welded dissimilar aluminum alloys AA7075-T6 and AA6061-T6. Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering. December 2021. doi:10.1177/09544089211065534.

[49] Jain, S., Sharma, N.K., & Gupta, R. (2018). Dissimilar alloys (AA6082/AA5083) joining by FSW and parametric optimization using Taguchi, grey relational and weight method. Engineering Solid Mechanics, 6, 51-66.