Gas Metal Arc Welding Modes in Wire Arc Additive Manufacturing of Ti-6Al-4V

Abstract

In wire arc additive manufacturing of Ti-alloy parts (Ti-WAAM) gas metal arc welding (GMAW) can be applied for complex parts printing. However, due to the specific properties of Ti, GMAW of Ti-alloys is complicated. In this work, three different types of metal transfer modes during Ti-WAAM were investigated: Cold Metal Transfer, controlled short circuiting metal transfer, and self-regulated metal transfer at a direct current with a negative electrode. Metal transfer modes were studied using captured waveform and high-speed video analysis. Using these modes, three walls were manufactured; the geometry preservation stability was estimated and compared using effective wall width calculation, the microstructure was analyzed using optical microscopy. Transfer process data showed that arc wandering depends not only on cathode spot instabilities, but also on anode processing properties. Microstructure analysis showed that each produced wall consists of phases and structures inherent for Ti-WAAM. α-basketweave in the center of and α-colony on the grain boundary of epitaxially grown β-grains were found with heat affected zone bands along the height of the walls, so that the microstructure did not depend on metal transfer dramatically. However, the geometry preservation stability was higher in the wall, produced with controlled short circuiting metal transfer.

Functional and Mechanical Properties of As-Deposited and Heat Treated WAAM-Built NiTi Shape-Memory Alloy

“…Nevertheless, it should be mentioned that the arc wandering effect was observed during printing. The abovementioned phenomenon was similar to that, occurring in the WAAM process, using Ti-alloy wire [32], and it affects the quality of the surface.…”

Improved Joint Formation and Ductility during Electron-Beam Welding of Ti6Al4V and Al6082-T6 Dissimilar Alloys

“…Usually, titanium and aluminum alloys are separately welded using different techniques, but gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) are most commonly used [10][11][12]. Of course, different methods for welding titanium alloys and aluminum alloys such as laser beam welding (LBW) [13,14], friction stir welding (FSW) [15,16], and electron-beam welding (EBW) [17,18] have also been suggested by previous authors.…”

Preliminary Process and Microstructure Examination of Flux-Cored Wire Arc Additive Manufactured 18Ni-12Co-4Mo-Ti Maraging Steel

“…WAAM offers lower maintenance costs and a higher deposition rate (up to 7-10 kg/h) than other AM processes [2,3]. Both new ways of conducting the process [4][5][6][7][8][9][10], strategies [11,12], and the use of new filler materials are investigated. WAAM parameters have a significant influence on the geometry and microstructure, which was studied by Dinovitzer et al [13].…”

“…The variable solubility of gases after the transition from liquid to solid, and the crystallization character, determine the potential presence of porosity or microporosity and hot cracks, also transcrystallisation influences the high anisotropy of mechanical properties [6,17,18,[32][33][34]. In the case of titanium alloys, the problem is their high reactivity to oxygen and coarse grains, which can be regulated by interlayer rolling/forging or inoculation [3][4][5]7,[35][36][37][38].…”