Three-dimensional modeling of transport phenomena and their effect on the formation of ripples in gas metal arc welding

2010 ◽  
Vol 107 (5) ◽  
pp. 054905 ◽  
Author(s):  
Z. H. Rao ◽  
J. Zhou ◽  
S. M. Liao ◽  
H. L. Tsai
Keyword(s):  
Arc Welding ◽  
Transport Phenomena ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Metal Arc Welding

Three-Dimensional Modeling of Gas Metal Arc Welding of Aluminum Alloys

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
H. Guo ◽  
J. Hu ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Welding Process ◽  
Weld Bead ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Metal Arc Welding ◽  
Arc Welding Process

A three-dimensional mathematical model and numerical techniques were developed for simulating a moving gas metal arc welding process. The model is used to calculate the transient distributions of temperature and velocity in the weld pool and the dynamic shape of the weld pool for aluminum alloy 6005-T4. Corresponding experiments were conducted and in good agreement with modeling predictions. The existence of a commonly observed cold-weld at the beginning of the weld, ripples at the surface of the weld bead, and crater at the end of the weld were all predicted. The measured microhardness around the weld bead was consistent with the predicted peak temperature and other metallurgical characterizations in the heat-affected zone.

Three-Dimensional Modeling of Plasma Arc in Arc Welding

2006 ◽  
Author(s):  
G. Xu ◽  
H. L. Tsai
Keyword(s):  
Magnetic Field ◽  
Weld Pool ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Plasma Arc ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling

Most previous three-dimensional modeling work in gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool. Almost all three-dimensional weld pool models are based on the two-dimensional axisymmetric Gaussian assumption of plasma arc pressure and heat flux. In this paper the three-dimensional plasma arc is modeled and results are presented. The velocity, pressure, temperature, current density, and magnetic field of the plasma arc are computed by solving the conservation equations of mass, momentum, and energy, as well as part of Maxwell's equations. This three-dimensional model allows one to study the non-axisymmetric plasma arc caused by external perturbations such as the external magnetic field. It also provides more accurate boundary conditions when modeling the welding pool. The future work is to unify it with the weld pool model and accomplish a complete three-dimensional model of GTAW and GMAW.

Modeling of Three-Dimensional Gas Metal Arc Welding With Groove

2007 ◽  
Author(s):  
J. Hu ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Plasma Arc ◽  
Droplet Impingement ◽  
Sulfur Species ◽  
Metal Arc Welding ◽  
Arc Pressure

This article analyzes the dynamic process of groove filling and the resulting weld pool fluid flow in gas metal arc welding of thick metals with V-groove. Filler droplets carrying mass, momentum, thermal energy, and sulfur species are periodically impinged onto the workpiece. The complex transport phenomena in the weld pool, caused by the combined effect of droplet impingement, gravity, electromagnetic force, surface tension, and plasma arc pressure, were investigated to determine the transient weld pool shape and distributions of velocity, temperature, and sulfur species in the weld pool. It was found that the groove provides a channel which can smooth the flow in the weld pool, leading to poor mixing between the filler metal and the base metal, as compared to the case without a groove.

Investigation of Transport Phenomena in Three-Dimensional Gas Metal Arc Welding of Thick Metals

2007 ◽  
Author(s):  
Jun Zhou ◽  
Mohammad S. Davoud ◽  
Hai-Lung Tsai
Keyword(s):  
Base Metal ◽  
Weld Pool ◽  
Arc Welding ◽  
Transport Phenomena ◽  
Gas Metal Arc Welding ◽  
Heat Diffusion ◽  
Liquid Region ◽  
Weld Penetration ◽  
Melt Flow ◽  
Metal Arc Welding

Arc welding is generally used to join thick metals in many engineering applications. However, poor penetration often occurs due to arc heat diffusion into the base metal. Hence, arc welding of thick metals normally requires grooving and/or preheating of the base metal and sometimes requires multiple passes for very thick metals or metals with high conductivity, such as aluminum alloys. In gas metal arc welding of thick metals with grooves and preheating, complicated melt flow and heat transfer are caused by the combined effect of droplet impingement, gravity, electromagnetic force, surface tension, and plasma arc pressure. Understanding these complicated transport phenomena involved in the welding process is critical in improving the penetration depth and weld quality. In this study, mathematical models and associated numerical techniques have been developed to study the effects of grooves and preheating on melt flow, diffusion of species, and weld penetration in gas metal arc welding of thick metals. Complex melt flow, transient weld pool shape and distributions of temperature and species in the weld pool are calculated. The continuum formation is adopted to handle liquid region, mushy zone and solid region. VOF technique is used to handle transient deformed shape of weld pool surface. The preliminary results show both grooves and preheating have important effects on the melt flow in weld pool and the weld penetration. Computer animations showing the evolutions of temperature; melt flow; and the interaction between droplets and weld pool will be presented.

Sign in / Sign up

Export Citation Format

Share Document