ORIGINAL ARTICLE Effects of tungsten inert gas (TIG) welding parameters on macrostructure, microstructure, and mechanical properties of AA6063-T5 using the controlled intermittent wire feeding method Ario Sunar Baskoro 1 & Mohammad Azwar Amat 1 & Alfian Ibnu Pratama 1 & Gandjar Kiswanto 1 & Winarto Winarto 2 Received: 14 December 2018 /Accepted: 6 September 2019 # Springer-Verlag London Ltd., part of Springer Nature 2019 Abstract This paper presents an automated or intermittent wire feeding method in tungsten inert gas (TIG) welding. The preliminary investigation shows the macrostructure, microstructure, and mechanical property effects on various welding parameters using one combination proportion of filler metal with various welding parameters. The result of microstructure has shown that the localized segregation occurred at the center area weld metal with high-density eutectic phase and energy dispersive X-ray spectroscopy (EDS) study has found that Mg content was higher compared to the outside region. Other sample microstructure shows columnar structure was formed in dilution boundaries, and it reveals that fast cooling rates happened when the filler wire was inserted. Also, microstructure on weld traverse section shows that the wavy-like structure depended on the heat input. The fracture mode shows that lack of heat input is susceptible to oxidation; therefore, the fracture tends to occur at weld metal in the brittle manner with reduced strength of more than 40%. Also this article presented the method to calculate length ratio (R L ) and the volume ratio (R V ) to estimate the minimum value of ratio under the condition of a good welded surface profile. Keywords TIG welding . AA6063-T5 . Intermittent wire feeder method . ER5356 . Microstructure 1 Introduction Aluminum alloys have been used in many applications such as aerospace, automotive industry, railway vehicles, bridges, ship structure, piping, auto-body parts, and part machined from plate or bar [1]. These alloys are frequently welded be- cause they have fairly good weldability and have many attrac- tive properties such as good formability and extrudability, recycling capabilities, corrosion resistance, high strength to weight ratio, high toughness, and low cost [2, 3]. Aluminum 6063 is one of the heat-treatable alloys that is very versatile and most widely used when medium strength is required. However, problems occurred when heat-treatable alloys are welded using fusion welding process. The phase transformation in the weld metal and softening in heat- affected zone inflict the decaying of mechanical properties [4]. In general, welding of aluminum alloys can be performed by using tungsten inert gas (TIG) or metal inert gas (MIG). However, MIG welding is not recommended for joining thin aluminum alloys due to excessive heat input that can cause distortion or melt through; therefore, TIG welding is preferred over MIG [5]. However, aluminum alloys have many disad- vantage properties that are associated with TIG welding pro- cess, such as high thermal conductivity and coefficient of thermal expansion, the presence of oxide layer in the alumi- num surface, solidification shrinkage, and high solubility of hydrogen and oxygen in the molten state [4]. And then, when these alloys are welded using TIG welding, they are more susceptible to solidification cracking on the fusion zone and loss of strength and ductility on the heat-affected zone (HAZ) [6]. The 6000 series of aluminum alloys containing magne- sium of more than 1 up to 3% are sensitive and susceptible to solidification cracking if the filler metal used the same com- position as the base metal. However, the cracking can be prevented by using the filler metal as a cladding that contains more than 3.5% magnesium (ex. ER5356) [7]. Wu and Wang [8] investigated that the use of high-magnesium fillers with * Ario Sunar Baskoro ario@eng.ui.ac.id 1 Mechanical Engineering Department, Faculty of Engineering, Universitas Indonesia, Depok, Indonesia 2 Metallurgical and Material Engineering Department, Faculty of Engineering, Universitas Indonesia, Depok, Indonesia The International Journal of Advanced Manufacturing Technology https://doi.org/10.1007/s00170-019-04400-y