Multiphysics Simulation and Experimental Investigation of Aluminum Wettability on a Titanium Substrate for Laser Welding-Brazing Process

Abstract

Abstract:The control of metal wettability is a key-factor in the field of brazing or welding-brazing. The present paper deals with the numerical simulation of the whole phenomena occurring during the assembly of dissimilar alloys. The study is realized in the frame of potential applications for the aircraft industry, considering the case of the welding-brazing of aluminum Al5754 and quasi-pure titanium Ti40. The assembly configuration, presented here, is a simplification of the real experiment. We have reduced the three-dimensional overlap configuration to a bi-dimensional case. In the present case, an aluminum cylinder is fused onto a titanium substrate. The main physical phenomena which are considered here are: the heat transfers, the fluid flows with free boundaries and the mass transfer in terms of chemical species diffusion. The numerical problem is implemented with the commercial software Comsol Multiphysics™, by coupling heat equation, Navier-Stokes and continuity equations and the free boundary motion. The latter is treated with the Arbitrary Lagrangian Eulerian method, with a particular focus on the contact angle implementation. The comparison between numerical and experimental results shows a very satisfactory agreement in terms of droplet shape, thermal field and intermetallic layer thickness. The model validates our numerical approach.

Microstructure Evaluation of the Potential of Additive Manufactured Dissimilar Titanium–Aluminum Alloys

“…Bai et al achieved more homogeneous heat input and lower residual stresses in WAAM components using IH. Improvement in the joint width between the Ti/Al interface is important to suppress oxidation in Al material [21] or the formation of an alumina film between Al and Ti [22]. Coating a fluor-based antioxidant flux on the Al component before depositing Ti is considered effective for ensuring the wetting of molten Ti when using alumina film [22].…”

“…Improvement in the joint width between the Ti/Al interface is important to suppress oxidation in Al material [21] or the formation of an alumina film between Al and Ti [22]. Coating a fluor-based antioxidant flux on the Al component before depositing Ti is considered effective for ensuring the wetting of molten Ti when using alumina film [22]. Common key factors for creating pure Ti or Ti-Al alloy layers on Al alloy components are the control of the heat input and penetration.…”

Laser Welding

“…The present special issue on "Laser Welding" was a success with a total of 16 original research works published after peer-review. Different topics were discussed within this special issue: modelling and simulation of laser welding were presented in [1][2][3][4]; porosity control by means of high speed imaging and microscopy techniques was studied and discussed [5]; the effect of processing parameters on the microstructure and mechanical properties of laser-welded joints was evaluated for different metallic systems such as AZ31 alloy [6], steels [7][8][9][10], Ti-based alloys [11][12][13], and Al-based alloys [14]; and finally, dissimilar laser welding of aluminum to steel was presented [15,16].…”

Numerical Simulations and Experimental Validation on LBW Bead Profiles of Ti-6Al-4V Alloy

“…Laser Beam Welding (LBW), a fusion joining technique, is characterized by small Heat Affected Zone (HAZ) and Fusion Zone (FZ), and minimal distortion. Advanced research is directed towards development of modeling and simulation tools, in addition to the process control in welding metallurgy (Wu et al, 2018;Ruan et al, 2018;Dal & Peyre, 2017;D'Ostuni et al, 2017;Popescu et al, 2017). Extensive studies are made on laser weld joint properties of metallic materials such as Al-based alloys (Zhang et al, 2017), AZ31 alloy (Lu et al, 2018), Al-steel (Cui et al, 2017;Casalino et al, 2017), steels (Górka & Stano, 2018;Mohammed et al, 2017;Xue et al, 2017;Evin & Tomáš, 2017), and Ti-based alloys (Zeng et al, 2017;Sánchez-Amaya et al, 2017;Caiazzo et al, 2017b).…”