This study aims to increase the penetration depth of an aluminium (A5052) weld pool in alternating current tungsten inert gas welding by controlling the cathode spot behaviour through the application of an external magnetic field. The external magnetic field direction was parallel to the base metal surface and perpendicular to the welding direction. The heat input from the distributed cathode spots was experimentally investigated using a high-speed video camera. The penetration depth almost doubled as a result of applying the optimal magnetic flux density of 5.5 mT. At this magnetic flux density, the largest number of cathode spots was concentrated in the weld pool, causing intensive heat input owing to the large cathode fall voltage and consequently leading to deeper penetration.
MathersG. The welding of Aluminium and its alloys. Cambridge, UK: Woodhead Publishing Ltd., 2002. Epub ahead of print 2002. DOI: 10.1007/s13398-014-0173-7.2
2.
JenneyCLO’BrienA. Welding handbook. Miami. FL: American Welding Society, 2015.
3.
KumarAMiltonMS. A comparison of welding techniques of aluminium alloys. A literature review. Int J Sci Res Sci Eng Technol2016; 2: 172–175.
4.
VermaRPKumar LilaM. A short review on aluminium alloys and welding in structural applications. Mater Today Proc2021; 46: 10687–10691.
SamiuddinMLiJlTaimoorM, et al.Investigation on the process parameters of TIG-welded aluminum alloy through mechanical and microstructural characterization. Def Technol2021; 17: 1234–1248.
7.
HuangYYuanYYangL, et al.A study on porosity in gas tungsten arc welded aluminum alloys using spectral analysis. J Manuf Process2020; 57: 334–343.
8.
PangQPangTMcClureJC, et al.Workpiece cleaning during variable polarity plasma arc welding of aluminum. J Manuf Sci Eng Trans ASME1994; 116: 463–466.
9.
TashiroSMiyataMTanakaM. Numerical analysis of AC tungsten inert gas welding of aluminum plate in consideration of oxide layer cleaning. Thin Solid Films2011; 519: 7025–7029.
10.
SansonnensLHaidarJLowkeJJ. Prediction of properties of free burning arcs including effects of ambipolar diffusion. J Phys D: Appl Phys2000; 33: 148–157.
11.
JüttnerB. Cathode spots of electric arcs. J Phys D: Appl Phys2001; 34: R103–R123.
12.
LancasterJF. The physics of welding. Oxford: Pergamon, 1986.
13.
TakedaKTakeuchiS. Effects of pressure on the cleaning action of cathode spot in low vacuum. Thin Solid Films2002; 407: 163–168.
14.
SatoAIwaoTYumotoM. Relation between surface roughness and number of cathode spots of a low-pressure arc. Plasma Sources Sci Technol2008; 17: 1–8.
15.
SarrafiRLinDKovacevicR. Real-time observation of cathodic cleaning during variable-polarity gas tungsten arc welding of aluminium alloy. Proce Inst Mech Eng Part B: J Eng Manuf2009; 223: 1143–1157.
16.
SarrafiRKovacevicR. Cathodic cleaning of oxides from aluminum surface by variable-polarity arc. Weld J2010; 89: 1–10.
17.
RoseSZährJSchnickM, et al.Arc attachments on aluminium during tungsten electrode positive polarity in TIG welding of aluminium. Rivista Italiana della Saldatura2012; 64: 71–79.
18.
PhanLHTashiroSBuiHV, et al.Investigating cathode spot behavior in argon alternating current tungsten inert gas welding of aluminum through experimental observation. J Phys D: Appl Phys2019; 52: 26LT02.
19.
PhanLHTashiroSBuiHV, et al.Influence of shielding gas on cathode spot behaviours in alternating current tungsten inert gas welding of aluminium. Sci Technol Weld Joining2020; 25: 258–264.
20.
PhanHLBuiVHTashiroS, et al.Influence of the magnesium content on cathode spot behavior in AC TIG welding of aluminum alloy. J Japan Weld Soc2019; 37: 181–186.
21.
McIntoshCMendezPF. Fall voltages in advanced waveform aluminum GMAW. Weld J2017; 96: 354s–366s.
22.
MiyasakaFOkudaTOhjiT. Effect of current wave form on AC TIG welding for aluminum alloys. Q J Japan Weld Soc2004; 22: 364–368.
23.
DutraJCCirinoLMHGonçalvesE, et al.AC-GTAW of aluminium – new perspective for evaluation of role of positive polarity time. Sci Technol Weld Joining2010; 15: 632–637.
24.
ChoJLeeJJBaeSH. Heat input analysis of variable polarity arc welding of aluminum. Int J Adv Manuf Technol2015; 81: 1273–1280.
25.
LiuZKadotaKTakadaK, et al.Development of new AC TIG welding power source and its improvement of productivity. Keikinzoku Yosetsu/J Light Metal Weld2020; 58: 43–47.
26.
SiewertEHussaryNSchickM, et al.New GTAW variant for high-throughput aluminum welding. Weld World2018; 62: 385–391.
27.
WuHChangYLuL, et al.Review on magnetically controlled arc welding process. Int J Adv Manuf Technol2017; 91: 4263–4273.
28.
BuiVHTrinhQNLeDK, et al.Effect of external magnetic field on arc characteristics and weld bead formation in metal-cored arc welding. Int J Adv Manuf Technol2025; 140: 4845–4858.
29.
YuJWangBZhangH, et al.Characteristics of magnetic field assisting plasma GMAW-P. Weld J2020; 99: 25s–38s.
30.
ShoichiMYukioMKokiT, et al.Study on the application for electromagnetic controlled molten pool welding process in overhead and flat position welding. Sci Technol Weld Joining2012; 18: 38–44.
31.
HanYChenJLiL, et al.Numerical investigation of arc-pool-metal vapor behavior in GTAW with an external magnetic field. Metals (Basel)2020; 10: 1199.
32.
SunQWangJCaoC, et al.Optimization of magnetic arc oscillation system by using double magnetic pole to TIG narrow gap welding. Int J Adv Manuf Technol2016; 86: 761–767.
