Friction Stir Spot Welding process (FSSW) is a distinct variant of Friction Stir Welding (FSW) that has been proven to be effective in various industrial applications. In this paper, FSSW joint on overlapped 3-mm-thick AA2017-T351 sheets aluminum alloy, welded with 1500 rpm as tool rotational speed, 5 mm/min plunge rate, 15 s as dwell time and 5.2 mm plunge depth, was investigated. Microstructural observations, microhardness measurements, tensile/shear tests and fractography of the spot weld were conducted. Results showed that thermal evolution and plastic deformation had a remarkable effect on the grain structure (the hardness is 124 HV at BM, decreases to 109 HV at HAZ/TMAZ and reaches 135 HV at SZ) and size (from typically 15 µm in BM to mainly under 2 µm in the SZ). The fully bonded region width was nearly 150 µm and the maximum tensile/shear load was 2.6 kN. Two types of fracture modes were analyzed following the tensile shear test, namely pull-out nugget and shear failure fracture mode.
MaZYFengAHChenDL, et al.Recent advences in friction stir welding/ processing of aluminum alloys: microstructural evolution and mechanical propoerties. Crit Rev Solid State Mater Sci2017; 43(4): 1–65.
6.
PicciniJMSvobodaHG. Effect of the tool penetration depth in friction stir spot welding (FSSW) of dissimilar aluminum alloys. Procedia Materials Science2015; 8: 868–877.
7.
ComminLDumontMMasseJE, et al.Friction stir welding of AZ31 magnesium alloy rolled sheets: influence of processing parameters. Acta Mater2009; 57: 326–334.
8.
SuryanarayananRSridharVG. Studies on the influence of process parameters in friction stir spot welded joints - A review. Mater Today Proc2021; 37: 2695–2702.
9.
KimJRAhnEYDasH, et al.Effect of tool geometry and process parameters on mechanical properties of friction stir spot welded dissimilar aluminum alloys. Int J Prec Eng Manuf2017; 18: 445–452.
10.
BattinaNMVanthalaVSPHariK. Effect of friction stir welding process parameters on mechanical and metallurgical behaviour of AA6061-T6 and AA2017-T6 tailored blanks. Engineering Research Express2021; 3: 025043.
11.
TozakiYUematsuYTokajiK. Effect of processing parameters on static strength of dissimilar friction stir spot welds between different aluminum alloys. Fatigue Fract Eng Mater Struct2007; 30: 143–148.
12.
ManuelNGalvãoILealR, et al.Nugget formation and mechanical behavior of friction stir welds of three dissimilar aluminum alloys. Materials (Basel)2020; 13: 2664.
13.
BoukraaMChekifiTMadaniT, et al.Enhancing friction stir welding performance for 2017AA alloy through cooling with Mediterranean seawater. Exp Tech2024; 49: 189–201.
14.
BattinaNMChiralaHKVanthalaVSP, et al.Experimental and finite element investigations on formability of friction stir welded tailor welds blanks of AA6061 and AA2017. Mater Today Proc2023; 3: 1–10.
15.
Da Costa GasparR. Torque and temperature analysis in FSSW of aluminum alloys. . Coimbra: PhD Thesis, Universidade de Coimbra, 2020.
16.
AndradeDGSabariSLeitaoC, et al.Shoulder related temperature thresholds in FSSW of aluminum alloys. Materials (Basel)2021; 14: 4375.
17.
AmaroAMReisPNBLoureiroA. Effect of friction stir weld parameters on hybrid bonded joints. The Journal of Adhesive2020; 97: 1136–1152.
18.
KahramanFKahramanADYolcuC, et al.Investigation of microstructures and mechanical properties of the joints which welded by the pinless tool and the designed tool to reduce the keyhole in the friction stir spot welding. European Journal of Engineering Science and Technology2019; 2: 1–10.
19.
HirasawaSHBadarinarayanHOkamotoK, et al.Analysis of effect of tool geometry on plastic flow during friction stir spot welding using particle method. J Mater Process Technol2010; 210: 1455–1463.
20.
ElyasiMTaherianJHosseinzadehM, et al.The effect of pin thread on material flow and mechanical properties in friction stir welding of AA6068 and pure copper. Heliyon2023; 9: 14752.
21.
AydinHTuncelOUmurY, et al.Effect of welding parameters on microstructure and mechanical properties of aluminium alloy AA6082-T46 friction stir spot welds. Indian Journal of Engineering & Materials Sciences2017; 24: 215–227.
22.
BagheriBAbbasiMAbdollahzadehA, et al.Advanced approach to modify friction stir spot welding process. Met Mater Int2020; 26: 1562–1573.
23.
GuerlichAYamamotoMNorthTH. Strain rates and grain growth in al 5754 and al 6061 friction stir spot welds. Metallurgical and Materials Transactions2007; 38: 1291–1302.
24.
MubiayiMP. Current developments in friction stir welding (FSW) and friction stir spot welding (FSSW) of aluminium and titanium alloys. Eng Proc2023; 56: 184.
25.
MirjaliliAJamshidi AvalHSerajzadehS. An investigation into the microstructure of friction-stir welded and artificially aged AA2017. J Mater Eng Perform2013; 22: 3566–3571.
26.
AbbasiMAbdollahzadehABagheriB, et al.Study on the effect of the welding environment on the dynamic recrystallization phenomenon and residual stresses during the friction stir welding process of aluminum alloy. J Mat Design Appl2021; 235: 1809–1826.
27.
LakshminarayananAKAnnamalaiVEElangoranK. Identification of optimum friction stir spot welding process parameters controlling the properties of low carbon automotive steel joints. J Mater Res Technol2015; 4: 262–272.
28.
TiwanNIMKusmono. Microstructure and mechanical properties of friction stir spot welded AA5052-H112 aluminium alloy. Heliyon2021; 7: 1–16.
29.
MahmoudTSKhalifaTA. Microstructural and mechanical characteristics of aluminium alloy AA5754 friction stir spot welds. J Mater Eng Perform2014; 23: 898–905.
30.
BadarinarayanHShiYLiX, et al.Effect of tool geometry on hook formation and static strength of friction stir spot welded aluminum 5754-O sheets. Int J Mach Tools Manuf2009; 49: 814–823.
31.
YinYHSunNNorthTH, et al.Hook formation and mechanical properties in A231 friction stir spot welds. J Mater Process Technol2010; 210: 2062–2270.
32.
SongXKeLXingL, et al.Effect of plunge speeds on hook geometries and mechanical properties in friction stir spot welding of A6061-T6 sheets. Int J Adv Manu Technol2014; 71: 2003–2010.
33.
SuryanarayananRSridharVG. Effect of process parameters in pinless friction stir spot welding of Al5754-Al6061 alloys. Metallography, Microstructure and Analysis2020; 9: 261–272.
34.
AhmedMMZWynneBPRainforthWM, et al.Microstructure, crystallographic texture and mechanical properties of friction stir welded AA2017A. Mater Charact2012; 64: 107–117.
35.
GaoZFengJWengZ, et al.Dislocation density-based modeling of dynamic recrystallized microstructure and process in friction stir spot welding of AA6082. Metals (Basel)2019; 9: 672–687.
36.
BeausirBFundenbergerJJ. Analysis tools for electron and X-ray diffraction, ATEX-software, www.atex-software.eu. France: Université de Lorraine - Metz, 2017.
37.
BakavosDPrangnellPB. Effect of reduced or zero pin legth and anvil insulation on friction stir spot welding thin gauge 6111 automotive sheet. Sci Technol Weld Joining2009; 14: 443–456.
38.
BozziSHelbert-EtterALBaudinT, et al.Influence of FSSW parameters on fracture mechanisms of 5182 aluminum welds. J Mater Process Technol2010; 210: 1429–1435.
39.
SarilaVKoneruHPCheepuM, et al.Microstructural and mechanical properties of AZ31B to AA6061 dissimilar joints fabricated by refill friction stir spot welding. Journal of Manufacturing and Materials Processing2022; 6: 95.
40.
LinYCLiuJJLinBY, et al.Effect of process parameters on strength of mg alloy AZ61 friction stir spot welds. Mater Des2012; 35: 350–357.
41.
AsadollahiMJebbariNNakhodehiS, et al.Analysis of tensile-shear strength of single and multi-friction stir spot welding joints under fixed welding process conditions. J Mech Eng Sci2020; 234: 1–12.
42.
MaryaMWangKHectorLG, et al.Tensile-shear forces and fracture modes in single and multiple weld specimens in dual-phase steels. J Manuf Sci Eng2006; 128: 287–298.
43.
HandeG. The mechanical behavior of friction stir spot welded aluminum alloys. The Minerals, Metals & Materials Society20142014; 66: 2156–2160.
44.
KulekciMK. Effect of process parameters on tensile shear strength of friction stir spot welded aluminum alloys (EN AW 5005). Archives of Mettalurgy and Materials2014; 59: 221–224.
45.
KulekciMKEsmeUErO. Experimental comparison of resistance spot welding and friction stir spot welding process for the EN AW 5005 aluminum alloy. Materials and Technologies2011; 45: 395–399.
46.
YuanWMishraRSWebbS, et al.Effect of tool design and process parameters on properties of al alloy 6016 friction stir spot welds. J Mater Process Technol2011; 211: 972–977.
47.
YuGChenXZhangB, et al.Tensile-Shear mechanical behaviors of friction stir spot weld and adhesive hybrid joint: experimental and numerical study. Metals (Basel)2020; 10: 1028–1047.
48.
ChenNWangHPCarlsonBE, et al.Fracture mechanisms of al/steel resistance spot welds in lap shear test. J Mater Process Technol2016; 243: 347–354.
49.
ZhangGXiaoCOjoOO. Dissimilar friction stir spot welding of AA2024-T3/AA7075-T6 aluminum alloys under different welding parameters and media. Defence Technology20212021; 17: 531–544.DOI: 10.1016/j.dt.2020.03.008
