Mechanism investigation of the influence of the magnetic field on the molten pool behavior during laser welding of aluminum alloy

2020 ◽  
Vol 162 ◽  
pp. 120390
Author(s):  
Longchao Cao ◽  
Qi Zhou ◽  
Huaping Liu ◽  
Jingchang Li ◽  
Shengyi Wang
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
Laser Welding ◽  
Molten Pool ◽  
The Magnetic Field

Fraction Solid Measurements on Solidifying Melt

2004 ◽  
Vol 126 (2) ◽  
pp. 193-197 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
Indirect Method ◽  
Eddy Currents ◽  
Solid Phase ◽  
Molten Metals ◽  
Metal Sample ◽  
Fraction Solid ◽  
The Magnetic Field ◽  
Good Agreement

A new indirect method to measure fraction solid in molten metals is presented. The method is based on the phenomena that when a metal sample (solid or liquid) rotates in a magnetic field (or the magnetic field rotates around a stationary sample), circulating eddy currents are induced in the sample, which generate an opposing torque related to amount of solid phase in a solidifying melt between the liquidus and solidus temperatures. This new technique is applied for measuring fraction solid on commercial A319 aluminum alloy. The solidification curves obtained by the proposed method at different cooling rates are in good agreement with predictions made by the Scheil model.

Fraction Solid Measurements on A319 Aluminum Alloy

2002 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
Eddy Currents ◽  
Solid Phase ◽  
Molten Metals ◽  
Metal Sample ◽  
Fraction Solid ◽  
A New Technique ◽  
The Magnetic Field ◽  
Good Agreement

A new indirect method to measure fraction solid on molten metals is presented. The method is based on the phenomena that when a metal sample (solid or liquid) rotates in a magnetic field (or the magnetic field rotates around a stationary sample), circulating eddy currents are induced in the sample, which generate an opposing torque proportional to amount of solid phase that precipitates in a solidifying melt between the liquidus and solidus temperatures. A new technique is applied for measuring fraction solid on commercial A319 aluminum alloy. The solidification curves obtained by the proposed method at different cooling rates are in a good agreement with the predictions made by the Scheil model.

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

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Jin Peng ◽  
Liqun Li ◽  
Shangyang Lin ◽  
Furong Zhang ◽  
Qinglong Pan ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Laser Welding ◽  
Welding Speed ◽  
Molten Pool ◽  
High Speed ◽  
Numerical Study ◽  
Flow Behavior ◽  
Front Wall ◽  
X Ray ◽  
Rear Part

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.

Numerical and experimental investigation of magnesium/aluminum laser welding with magnetic field

2021 ◽  
Author(s):  
Jiafu Zhou ◽  
Dianwu Zhou ◽  
Jinshui Liu
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Laser Welding ◽  
Molten Pool ◽  
Three Dimensional ◽  
Flow Region ◽  
Metal Vapor ◽  
Element Distribution ◽  
Welding Pool ◽  
Metal Vapor Plasma

Abstract A three-dimensional numerical model for thermal-fluid-metallurgical coupling was established to inspect the effect from a stable longitudinal magnetic field on molten pool of magnesium/aluminum laser welding. Magnetic field-assisted laser welding platform was built to test the morphology and spectrum of the metal vapor/plasma. The scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) were used to determine the morphology and element distribution of molten pool cross section. Simulation results showed that temperature gradient of molten pool was reduced, heat distribution became uniform, and keyhole area was enlarged. In addition, the flow velocity of molten pool was increased, the vorticity of molten pool was improved, and the flow region of liquid metal was enlarged. Experimental results showed that penetration of molten pool was deeper, the shape of welding pool tended to be symmetrical and the density of Al element distribution in welding pool was increased by magnetic field. Thus, heat and mass transfer in welding pool was promoted due to the application of magnetic field, the elements exchange and the convection of liquid metal were accelerated, and the distribution of Mg-Al compounds should be dispersed under the agitation of Lorentz force. It’s predicted that the distribution of Mg-Al compounds in magnesium/aluminum laser welding would be positively affected by magnetic field, which was beneficial to control the weld quality. Hence, numerical results and experimental verification shared good consistency.

On the fluid behavior and stability of Ti-6Al-4V titanium alloy GMAW molten pool: Effect of the longitudinal magnetic field

2021 ◽  
pp. 2150283
Author(s):  
Chenglong Wu ◽  
Shaohua Han ◽  
Dingqi Xue ◽  
Jianbin Zhan
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Molten Pool ◽  
Longitudinal Magnetic Field ◽  
Liquid Metals ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Surface Profile ◽  
Length Change ◽  
The Magnetic Field

By establishing a three-dimensional (3D) numerical simulation of the Ti-6Al-4V Gas Metal Argon Welding (GMAW) molten pool, the molten pool’s heat transfer and fluid flow behavior under a longitudinal magnetic field were investigated. The simulation results show that when the droplet enters the molten pool, the liquid metals on the molten pool’s surface symmetrically flow towards both sides of the molten pool from different angles. With the increase of the magnetic field strengthens, the temperature gradually decreases, and the fluid flow velocity increases continuously. Besides, the magnetic field strength is correlated positively with the molten pool’s size with a certain range of 0–0.03 T. However, when the magnetic field strengthens reach 0.04 T, the magnetic field is correlated negatively with the molten pool’s size. Because the Marangoni and buoyancy begin to weaken, the molten pool’s length change occurs before the width change. Simultaneously, a sizeable velocity region appears on the left side of the molten pool. Thus, the liquid metal gathers on the left side, resulting in the weld cross-section’s asymmetry. It can conclude that only when the magnetic strengthen keeps in the range of 0–0.03 T, the longitudinal magnetic field can make the molten pool’s surface profile smooth.

Quantitative Nondestructive Evaluation of the Aluminum Alloy Using the Sheet Type Induced Current and the Single Sensor Scanning

2009 ◽  
Vol 417-418 ◽  
pp. 641-644 ◽  
Author(s):  
Jong Woo Jun ◽  
Jin Yi Lee ◽  
Ki Su Shin ◽  
Jung Ho Hong
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
Vertical Direction ◽  
Crack Size ◽  
Induced Current ◽  
Paramagnetic Materials ◽  
Crack Tips ◽  
Single Sensor ◽  
The Magnetic Field ◽  
Testing And Evaluation

Single sensor scanning (hereafter SSS) used to inspect cracks on paramagnetic materials can measure the distribution of the root mean squared value (RMS) of the magnetic field around crack tips quantitatively when sheet type current is induced on the specimen. The vertical direction magnetic field alternates to the surface of the crack tips because the sheet type induced current on the specimen is distorted by the existence of the crack in an SSS system. The RMS distribution of the magnetic field, which can be measured by using SSS, depends on the crack size and shape, so it can be used to evaluate a crack size quantitatively. An algorithm of quantitative nondestructive testing and evaluation of cracks of various shapes and sizes on the aluminum alloy, Al7075 is proposed in this paper.

Observing the galactic magnetic field

1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst
Keyword(s):  
Magnetic Field ◽  
Fair Agreement ◽  
Solar Neighbourhood ◽  
Galactic Magnetic Field ◽  
The Magnetic Field

Various methods of observing the galactic magnetic field are reviewed, and their results summarized. There is fair agreement about the direction of the magnetic field in the solar neighbourhood:l= 50° to 80°; the strength of the field in the disk is of the order of 10-5gauss.

Sign in / Sign up

Export Citation Format

Share Document