Unsteady interfacial phenomena during inward weld pool flow with an active surface oxide

Zhao, Chunxiao; Steijn, Volkert van; Richardson, I.M.; Kleijn, Chris R.; Kenjereš, Saša; Saldi, Zaki S.

doi:10.1179/136217108x370281

Cited by 27 publications

(16 citation statements)

References 29 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous numerical studies on heat and fluid flow in low-Prandtl melting pools with surfactants have shown that the molten metal flow can be very unstable at high Marangoni numbers [6,7,15]. However, deformations of the melt pool surface as observed experimentally [5,17] were not accounted for in those studies. The aim of the present work is to understand the effect of surface deformations on flow instabilities in a liquid metal melting pool with surfactant.…”

Section: Introductionmentioning

confidence: 97%

The Influence of Surface Deformation on Thermocapillary Flow Instabilities in Low Prandtl Melting Pools with Surfactants

Ebrahimi¹,

Kleijn²,

Richardson³

2019

Proceedings of the 5th World Congress on Mechanical, Chemical, and Material Engineering

View full text Add to dashboard Cite

Heat and fluid flow in low-Prandtl number melt pools (Pr = O(10 −1)) during laser processing of materials are sensitive to the prescribed boundary conditions, and the responses are highly nonlinear. Previous studies have shown that fluid flow in melt pools with surfactants can be unstable at high Marangoni numbers. In numerical simulations of molten metal flow in melt pools, surface deformation and its influence on the energy absorbed by the material are often neglected. However, this simplifying assumption may reduce the level of accuracy of numerical predictions with surface deformations. In the present study, we carry out three-dimensional numerical simulations to realise the effects of surface deformations on thermocapillary flow instabilities in laser melting of a metallic alloy with surfactants. Our computational model is based on the finite-volume method and utilises the volumeof-fluid (VOF) method for gas-metal interface tracking. Additionally, we employ a dynamically adjusted heat source model and discuss its influence on numerical predictions of the melt pool behaviour. Our results demonstrate that including free surface deformations in numerical simulations enhances the predicted flow instabilities and, thus, the predicted solid-liquid interface morphologies.

show abstract

Section: Introductionmentioning

confidence: 97%

The Influence of Surface Deformation on Thermocapillary Flow Instabilities in Low Prandtl Melting Pools with Surfactants

Ebrahimi¹,

Kleijn²,

Richardson³

2019

Proceedings of the 5th World Congress on Mechanical, Chemical, and Material Engineering

View full text Add to dashboard Cite

show abstract

“…Although many results have been reported for oxygen effect in low-energy-density welding process, few have touched that in high-energy-density laser welding [38][39][40], especially in the keyhole mode welding. As the most commonly encountered welding atmosphere, air and argon are used as welding atmosphere and compared in the present study.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical study on laser keyhole welding of 42CrMo under air and argon atmosphere

et al. 2016

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Laser keyhole welding of 42CrMo in air and argon atmospheres has been studied both experimentally and numerically. Significant macroscale difference is observed for welding carried out under argon and air shielding. Fusion zone of welding under argon shielding has a "▽" shape, while it has a "U" shape for welding in air. The surface of the weldment is smoother for welding in argon when compared with that in air. Oxygen effect is proposed to account for the experimental results. A three-dimensional heat transfer model with a predefined keyhole is developed to study the heat transport and fluid flow in laser welding process. The variation of weld pool geometry and temperature history is investigated for different oxygen concentrations. It is found that a small amount of oxygen could significantly modify the weld pool dimension, while keeping the temperature history of materials, and thus the microstructure, in the fusion zone and heat-affected zone unchanged.

show abstract

“…In fact, the temperature coefficient of surface tension is a function of temperature and surfactants content. The weld pool flow can be affected by the distributions of both the activating element and temperature at the weld pool [39,43]. This is an issue of significance to be given more focus sequentially.…”

Section: Grmentioning

confidence: 99%

Investigation of heat transfer and fluid flow in activating TIG welding by numerical modeling

Wang

Huang²,

Huang³

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

Heat transfer and fluid flow of arc plasma and weld pool in tungsten inert gas (TIG) welding and activated flux tungsten inert gas (A-TIG) welding of SUS 304 stainless steel are investigated comparatively though a 3D unified model. The model differs from the previous ones in that it considers the arc length more realistic for welding production. Tungsten electrode, anode (work piece) and arc plasma are all included. The effects of buoyance, plasma drag force, Lorentz force and Marangoni force on the weld pool flow are taken into account. By solving the conservation equations of mass, momentum, energy as well as Maxwell equations, the distributions of temperature and velocity of arc plasma and weld pool are obtained for TIG and A-TIG welding. The heat flux, current density and shear stress at the

show abstract

Unsteady interfacial phenomena during inward weld pool flow with an active surface oxide

Cited by 27 publications

References 29 publications

The Influence of Surface Deformation on Thermocapillary Flow Instabilities in Low Prandtl Melting Pools with Surfactants

The Influence of Surface Deformation on Thermocapillary Flow Instabilities in Low Prandtl Melting Pools with Surfactants

Experimental and numerical study on laser keyhole welding of 42CrMo under air and argon atmosphere

Investigation of heat transfer and fluid flow in activating TIG welding by numerical modeling

Contact Info

Product

Resources

About