Gas tungsten arc welding (GTAW) is the primary process for precision joining of metals due to its capability for accurate control of heat input. As a close relative and modification of GTAW, plasma arc welding (PAW) has higher energy density and can penetrate thicker workpieces while maintaining the desired capability for accurate control of heat input. In order to produce quality welds consist...

Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by a shielding gas (usually an inert gas such as argon), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it. A const...

Keyhole arc welding (KAW), including the keyhole double-sided arc welding process being developed at the University of Kentucky and keyhole plasma arc welding, can achieve much deeper narrower penetration than all other arc welding processes. If it could be controlled such that the heat input and weld pool are minimized while at the same time the desired full penetration is guaranteed, it could...

Arc plasma possesses a constriction phenomenon with a pulsed current. The constriction is created by the Lorentz force, the radial electromagnetic force during arc welding, which determines the energy distribution of the arc plasma. Welding experiments were carried out with ultra-high-frequency pulsed arc welding (UHFP-AW). Ultra-high-speed camera observations were produced for arc surveillance...

A new spectroscopic parameter is used in this paper for on-line arc-welding quality monitoring. Plasma spectroscopy applied to welding diagnostics has typically relied on the estimation of the plasma electronic temperature, as there is a known correlation between this parameter and the quality of the seams. However, the practical use of this parameter gives rise to some uncertainties that could...

Tungsten inert gas (TIG) welding, also called as gas tungsten welding 1. (a) Schematic of TIG welding Process (b) Variety of tungsten electrodes. The activated TIG (ATIG) welding process mainly focuses on increasing the depth of penetration and the reduction in the width of weld bead has not been paid. Tungsten inert gas welding, TIG is widely applied in manufacturing process for different The ...

This paper describes the relationships between ultra-violet emission, ozone generation and CrVI production in MIG welding which were measured as a function of shield gas flow rate, welding voltage, electrode stick-out and shield gas composition using an automatic welding rig that permitted MIG welding under reproducible conditions. The experimental results are interpreted in terms of the physic...

Most previous welding simulations are based on a flat weld pool surface and become unmeaningful when the surface deformation is significant. In recent years, some researchers have developed numerical models capable of simulating free surface motion in welding processes, but they focus on the discussions of physical equations, boundary conditions, and solutions, rather than the numerical algorit...

A new fiber sensor system designed for spectroscopic analysis and on-line quality assurance of arc-welding processes is presented here. Although several different approaches have been considered for the optical capture of plasma emission in arc-welding processes, they tend to be invasive and make use of optical devices such as collimators or photodiodes. The solution proposed here is based on t...

Results from a computational model of arc welding, in which the arc plasma, workpiece and electrode are treated self-consistently, are presented. It is demonstrated through three examples (the effect of shielding gas composition, metal vapour and electrode shape on the weld pool) that reliable prediction of weld pool depth and geometry requires that the arc plasma is included in the computation...