A unified model for coupling mesoscopic dynamics of keyhole, metal vapor, arc plasma, and weld pool in laser-arc hybrid welding

Chen, Xin; Mu, Zhongyan; Hu, Renzhi; Liu, Liang; Murphy, Anthony B.; Pang, Shengyong

doi:10.1016/j.jmapro.2019.03.034

Cited by 27 publications

(20 citation statements)

References 54 publications

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“…Substituting Equations (26) and (27) into Equation 24and conducting some manipulation, we get the variation of the diffusion coefficient of plasma arc with ultrasound, and (D ee ) add are thermal and ordinary diffusion coefficients respectively, which are induced by the ultrasound. ρ e and ρ h represent electron mass density and heavy particle mass density, respectively According to [16], the total diffusion coefficients can be written as:…”

Section: (3) Diffusion Coefficient Variation Caused By Ultrasoundmentioning

confidence: 99%

“…The general theory and calculation method of gas transport coefficients have been systematically studied [14][15][16], and many researchers have also calculated the transport coefficients of various gases such as argon and helium, including the calculation of transport coefficients of two-temperature plasma [17,18] and mixed plasma [19,20]. The roles of shielding gas and metal vapour in affecting the plasma arc [21][22][23][24] and the coupling mechanism of plasma arc-keyhole-weld pool [25][26][27] have been numerically simulated. The energy balance and transport coefficients have a significant impact on arc pressure [28].…”

Section: Introductionmentioning

confidence: 99%

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Effects of Ultrasonic Vibration on the Transport Coefficients in Plasma Arc Welding

Chen

2020

Metals

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In ultrasound assisted plasma arc welding (U-PAW), the exerted ultrasonic vibration on the tungsten electrode interacts with the plasma arc and changes its heat-pressure characteristics. It is of great significance to investigate the underlying interaction mechanism. In this study, the calculation method of transport coefficients in U-PAW is developed. Translational thermal conductivity (including electrons thermal conductivity and the thermal conductivity of heavy particles) and electrical conductivity are calculated by considering the second-order approximation of Maxwell velocity distribution function, while the method of Butler et al. is adopted to calculate the reaction thermal conductivity in U-PAW. The effective value of the ultrasound velocity gradient tensor is employed to describe the effects of ultrasonic vibration on transport coefficients in ultrasound assisted plasma arc. The calculation results show that when the ultrasound is applied, the thermal conductivity of heavy particles in the plasma increases significantly and the electron thermal conductivity increases within some extent. The thermal conductivity of the reaction also increased to a great extent, and the electrical conductivity decreases a little bit. Although the thermal diffusion coefficient also has some increase, but the ordinary diffusion coefficient is obviously reduced due to the application of the ultrasound. With the updated transport coefficients, the plasma arc pressure on the anode surface is numerically computed, and the predicted pressures of PAW and U-PAW can be consistent with the measured ones.

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Section: (3) Diffusion Coefficient Variation Caused By Ultrasoundmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of Ultrasonic Vibration on the Transport Coefficients in Plasma Arc Welding

Chen

2020

Metals

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“…(2) In the hybrid plasma region, the mass, momentum and energy equations of hybrid plasma are [16]: Note that the subscript 'g' and 'm' indicate the hybrid plasma region and the mixture fluid phase region, respectively.…”

Section: Governing Equationsmentioning

confidence: 99%

“…Based on our recently proposed new model [16], we quantitatively analyzed the LIADD phenomenon in LTHW of 316L stainless steel. Fig.…”

Section: Prediction Of Laser Induced Arc Dynamics Destabilizationmentioning

confidence: 99%

“…The high-speed video camera with an 808 nm band filter is used to observe the evolution of the arc shape. The unified laser-TIG model [16] used in this work considers the complex interaction between laser and arc. We experimentally and theoretically demonstrate that the laser action significantly constricts arc and oscillates the arc tail with a 1~3 kHz high frequency.…”

Section: Introductionmentioning

confidence: 99%

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Laser induced arc dynamics destabilization in laser-arc hybrid welding

Mu¹,

Chen²,

Hu³

et al. 2019

J. Phys. D: Appl. Phys.

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The interaction between laser and arc plasma is a central issue in laser-arc hybrid welding. We report a new interaction phenomenon called laser destabilizing arc dynamics in kilowatt fiber laser-TIG hybrid welding of 316L stainless steel. We found the laser action significantly oscillates the arc tail with a 1~3 kHz high frequency. Direct numerical simulation demonstrates that the destabilization mechanism is due to the high-speed oscillated metal vapor ejecting from the mesoscopic keyhole. More interesting, the high-speed metal vapor could contrict the arc plasma by physical shielding. This provides a fundamentally different explanation from the generally adopted metal vapor ionization theory for laser constrict arc plasma phenomenon. Also, the results substantiate that the arc plasma cannot easily enter into the keyhole because of the violent metal vapor.

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Modeling of Arcing, Scrap Melting, and Temperature Evolution in the Refractory of a Lab‐Scale Direct Current‐Electric Arc Furnace

Nath,

Maji,

Singh

2024

steel research int.

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Refractory linings of electric arc furnaces are subjected to intense thermal loads, leading to occasional failure of the insulating bricks. A numerical model that simulates the phenomena of arcing, scrap melting, and the transient thermal evolution in the refractory lining of a laboratory‐scale direct current‐electric arc furnace (DC‐EAF) is developed. The rise in the temperature of the refractory lining depends on many factors, including the duration of the melting operation, the intensity and duration of arcing, the design of the furnace, thermophysical properties, and the thickness of the lining. Continuum formulation‐based equations for the transport of momentum, energy, and species, auxiliary models of phase changes associated with scrap melting and evaporation of metal under the arc and Maxwell's equations are solved in a conjugate domain to model the progress of the melting of the scarp and temperature evolution in the refractory lining. Combining experimental data from lab‐scale DC‐EAF, the model is enhanced to represent the laboratory experiment. Scrap with high porosity needs more time for melting, and thermal damage of refractory lining is linked to prolonged arcing coupled with the poor quality of refractory materials.

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A unified model for coupling mesoscopic dynamics of keyhole, metal vapor, arc plasma, and weld pool in laser-arc hybrid welding

Cited by 27 publications

References 54 publications

Effects of Ultrasonic Vibration on the Transport Coefficients in Plasma Arc Welding

Effects of Ultrasonic Vibration on the Transport Coefficients in Plasma Arc Welding

Laser induced arc dynamics destabilization in laser-arc hybrid welding

Modeling of Arcing, Scrap Melting, and Temperature Evolution in the Refractory of a Lab‐Scale Direct Current‐Electric Arc Furnace

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