Effects of temperature-dependent material properties and shielding gas on molten pool formation during continuous laser welding of AZ91 magnesium alloy

Bannour, Sana; Abderrazak, Kamel; Mhiri, Hatem; Palec, Georges Le

doi:10.1016/j.optlastec.2012.03.034

Cited by 41 publications

(19 citation statements)

References 20 publications

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“…Bannour et al [10] have studied the temperature dependence of physical properties during welding, and they have considered convection losses. Several authors have shown that energy dissipates on surface by convection and radiation [11,12].…”

Section: List Of Symbolsmentioning

confidence: 99%

Semi-analytic algorithms for the electrohydrodynamic flow equation

et al. 2012

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Laser welding is being used more frequently in industrial processes because of its advantages; therefore, energy loss in welding is an important issue during planning and operation. We calculated the energy losses expected during the laser welding of TA6V titanium alloy. We used the heat equation to describe the energy distribution of solid and liquid TA6V. The solid-to-liquid phase change was taken into account by comparing the accumulated energies and enthalpy of fusion. A numerical model was used to calculate the energy lost by convection and radiation. Finite difference calculations were performed using a FORTRAN-based computer program to solve the heat equation. The numerical results suggested that the appropriate laser welding velocity and power were in good agreement with the experimental data published elsewhere in the literature. The results showed the importance of the influence of the energy lost by radiation and convection in the welding area on welding energies and temperatures.Keywords Laser welding Á Heat equation Á Enthalpy of fusion Á Convection Á Thermal radiation Á Titanium alloyPower density at the center of the beam (W m

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Section: List Of Symbolsmentioning

confidence: 99%

Semi-analytic algorithms for the electrohydrodynamic flow equation

et al. 2012

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“… The surface of the weld pool is considered flat (Yokohara et al 2016, Hozoorbakhsh et al 2016, Chang et al 2013, Bannour et al 2012, Abderrazak et al 2009, Wang et al 2007. So, the complex physical mechanisms related to the keyhole formation and stability are disregarded.…”

Section: Mathematical Formulationmentioning

confidence: 99%

“…This gas is chosen based on parameters such as: its nature, the geometry of the nozzle, jet angle, jet velocity, etc. Bannour et al (2012) had investigated numerically and experimentally the effects of different flow rates, using a simple circular nozzle, on the horizontal welding pool dimensions and temperature distributions. They reported that the shielding gas affects all the weld characteristics such as the shape, penetration and efficiency.…”

Section: Introductionmentioning

confidence: 99%

Shielding Gas Coaxial Jet Pipes Numerical Study of a Vertical Laser Welding Process of AZ91 Magnesium Alloy

Boughanmi¹,

Bannour²,

Mhiri³

et al. 2018

JAFM

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The laser welding of magnesium alloys, largely used in many fabrication applications, has gained considerable interest especially in aerospace, electronics, automotive industry etc. Unfortunately, this process is associated to an undesired phenomenon which is "oxidation". For this reason, a good shielding system of the welding zone is of major importance. This paper presents a numerical study using computational fluid dynamics (CFD) of a laser welding process employing a moving volumetric heat source. Starting with the turbulence model validity, a parametric study of this welding process in a vertical position aiming to optimize the design of protection gas device, the gas jet inclination, the appropriate welding direction and the gas type is, then, proposed. The optimum parametric combination ensuring the largest gas coverage area is the one where the shielding gas is Argon, supplied by the coaxial nozzles at a downward inclination angle with respect to the laser beam axis, and a downward welding direction.

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“…The molten pool shape and temperature distribution were affected by variations in thermal properties [18]. Consequently, some thermophysical properties dependent on temperature were written as follows:…”

Section: Mathematical Modellingmentioning

confidence: 99%

High-Speed X-Ray Transmission and Numerical Study of Melt Flows inside the Molten Pool during Laser Welding of Aluminum Alloy

Jin

Lin

et al. 2016

Mathematical Problems in Engineering

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By using the X-ray transmission imaging system, melt flows inside a molten pool were studied during laser welding of aluminum alloy at different welding speeds. Then, the correlation between temperature gradients along the direction of weld penetration and melt flows in the rear part of a molten pool was analyzed by using a three-dimensional numerical method. And the presented model was verified by experimental results. The corresponding investigation was carried out to further study the correlation between temperature gradient and melt flow behavior of the molten pool in the plate heated by preheating temperature. The results indicated that, in the rear part of the molten pool, the maximum flow velocity was located at the bottom of the molten pool. The melt metal in the rear molten pool caused by different welding speeds had significantly different flow trends. As the welding speed increased, the absorbed intensity on the keyhole front wall also increased as well as the recoil pressure that could maintain the keyhole opened. Consequently, the increase of the welding speed was more beneficial to improving the stability of the molten pool.

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Effects of temperature-dependent material properties and shielding gas on molten pool formation during continuous laser welding of AZ91 magnesium alloy

Cited by 41 publications

References 20 publications

Semi-analytic algorithms for the electrohydrodynamic flow equation

Semi-analytic algorithms for the electrohydrodynamic flow equation

Shielding Gas Coaxial Jet Pipes Numerical Study of a Vertical Laser Welding Process of AZ91 Magnesium Alloy

High-Speed X-Ray Transmission and Numerical Study of Melt Flows inside the Molten Pool during Laser Welding of Aluminum Alloy

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