In the paper solid state bonding conditions obtained in friction stir welding (FSW) of AA5754-H111 butt joints are analysed, considering the so called zigzag line in the transverse section of the joints. A wide experimental campaign was carried out varying both tool advancing speed and tool rotational one. The effects of the process on the mechanical properties of the joint were highlighted and micro- and macro-observations were used in order to explain the reasons of the enhanced mechanical properties found for the welded material. Numerical results derived from a FEM model previously developed by the authors were utilised to point out the different mechanical and metallurgical behavior of the obtained joints.
PeelM, SteuwerA, PreussM, WithersPJ: ‘Microstructure, mechanical properties and residual stresses as a function of welding speed in aluminium AA5083 friction stir welds’, Acta Mater., 2003, 51, (16), 4791–4801.
LeitaoC, LealRM, RodriguesDM, LoureiroA, VilaçaP: ‘Mechanical behaviour of similar and dissimilar AA5182-H111 and AA6016-T4 thin friction stir welds’, Mater. Des., 2009, 30, (1), 101–108.
11.
PeelMJ, SteuwerA, WithersPJ: ‘Dissimilar friction stir welds in AA5083-AA6082. Part II: process parameter effects on microstructure’, Metall. Mater. Trans. A, 2006, 37A, (7), 2195–2206.
12.
MilesMP, DeckerBJ, NelsonTW: ‘Formability and strength of friction-stir-welded aluminum sheets’, Metall. Mater. Trans. A, 2004, 35A, (11), 3461–3468.
13.
LombardH, HattinghDG, SteuwerA, JamesMN: ‘Effect of process parameters on the residual stresses in AA5083-H321 friction stir welds’, Mater. Sci. Eng. A, 2009, A501, 119–124.
14.
ZhangZ, YangX, ZhangJ, ZhouG, XuX, ZouB: ‘Effect of welding parameters on microstructure and mechanical properties of friction stir spot welded 5052 aluminum alloy’, Mater. Des., 2011, 32, (8–9), 4461–4470.
15.
LiuHJ, ChenYC, FengJC: ‘Effect of zigzag line on the mechanical properties of friction stir welded joints of an Al-Cu alloy’, Scr. Mater., 2006, 55, 231–234.
16.
SatoYS, YamashitaF, SugiuraY, ParkSHC, KokawaH: ‘FIB-assisted TEM study of an oxide array in the root of a friction stir welded aluminium alloy’, Scr. Mater., 2004, 50, 365–369.
17.
KotaniK, JungJP, IkeuchiK, MatsudaF: ‘Effects of interfacial phases on bond strength of diffusion-bonded joints of Al-X binary alloys (X = Mg, Si, Mn, Zn, Cu) – diffusion-bonding mechanism of Al alloys by transmission electron microscopy’, J. Jpn Weld. Soc., 2000, 18, 580–589.
18.
XieGQ, OhashiO, YamaguchiN, SongMH, FuruyaK., Noda: ‘TEM observation of interfaces between particles in Al-Mg alloy powder compacts prepared by pulse electric current sintering T’, Mater. Trans., 2002, 43, 2177–2180.
19.
LumleyRN, SercombeTB, SchaferGB: ‘Surface oxide and the role of magnesium during the sintering of aluminum’, Metall. Mater. Trans. A, 1999, 30A, 457–463.
20.
FratiniL, BeccariS, BuffaG: ‘Friction stir welding FEM model improvement through inverse thermal characterization’, Trans. NAMRI/SME, 2005, 33, 259–266.
21.
BuffaG, HuaJ, ShivpuriR, FratiniL: ‘A continuum based fem model for friction stir welding – model development’, Mater. Sci. Eng. A, 2006, A419/1-2, 389–396.
22.
‘ASM speciality handbook’, ‘Aluminum and aluminum alloys’, (ed. DavisJ R, ed); 1993, Materials Park, OH, ASM International, Davis & Associates.
23.
‘Hot working guide’, (ed. PrasedY V R K, SasidharaS, ed); 1997, Materials Park, OH, ASM International.
24.
BuffaG, FratiniL, La SpisaD: ‘Mechanical and microstructural modifications induced by friction stir welding and processing on AA5754 aluminum alloys’, Proc. 10th Int. Conf. on ‘Techn. Plast.’ (ICTP 2011), 752–756.
25.
BuffaG, FratiniL, MicariF, PreviteG: ‘Factors influencing bonding mechanics in FSW of AA5754’, Key Eng. Mater., 2012, 491, 89–96.
26.
DehghaniK, ChabokA: ‘Dependence of Zener parameter on the nanograins formed during friction stir processing of interstitial free steels’, Mater. Sci. Eng. A, 2011, A528, 4325–4330.
ChangCI, LeeCJ, HuangJC: ‘Relationship between grain size and Zener-Holloman parameter during friction stir processing in AZ31 Mg alloys’, Scr. Mater., 2004, 51, 509–514.
29.
BuffaG, HuaJ, ShivpuriR, FratiniL: ‘Design of the friction stir welding tool using the continuum based FEM model’, Mater. Sci. Eng. A, 2006, A419/1-2, 382–388.
