Weld joint penetration control is a basic research topic in the welding research community. The authors propose using an innovative plasma arc welding process referred to as the quasi-keyhole process to achieve less application-dependent weld joint penetration sensing and control. To control the quasi-keyhole process, the peak current and keyhole sustaining current are selected as the control v...

\Ye present a general overview of a method of numerically modelling deep penetration welding processes using geometric constraints based on boundary information obtained from experiment. We consider general issues concerning accurate numerical calculation of temperature and velocity fields in regions of the meltpool where the flow of fluid is characterized by quasi-stationary Stokes flow. It is...

In regular arc welding, the arc heat is transferred from the surface of the workpiece to melt it. In keyhole plasma arc welding, the workpiece is melted by the plasma jet which heats the wall of the keyhole along the thickness direction. Penetration is achieved with reduced heat input. However, the plasma jet only gains its energy in the arc before reaching the keyhole. In the keyhole where no ...

Numerical and experimental studies were conducted to investigate the heat transfer, fluid flow, and keyhole dynamics during a pulsed keyhole laser welding. A comprehensive mathematical model has been developed. In the model, the continuum formulation was used to handle solid phase, liquid phase, and mushy zone during melting and solidification processes. The volume-of-fluid method was employed ...

Introduction: Recent advancement of intravascular technique has minimized the operative invasiveness. In rivalry with this technique, aneurysmal clipping has become less and less invasive. Hitherto, three less invasive surgical approaches as supraorbital keyhole approach, lateral supraorbital keyhole approach, and pterion keyhole approach, have been proposed for the clipping of the anterior cir...

Quasi-keyhole is a novel approach proposed to operate the keyhole arc welding process. Because the method’s effectiveness depends on the amperage of the peak current used to establish the keyhole, this paper proposes adjusting the amperage based on the duration of the peak current, which equals the keyhole establishment time. A nominal model structure has been selected from those identified usi...

Absctract This paper presents a quantitative evaluation of the effect of the keyhole technique on contrast-enhanced dynamic MRI; specifically, the effect of the observed region of interest on keyhole images compared to a complete set of data was evaluated. The limiting condition of the quantitative use of the keyhole approach was defined and exemplified. Results obtained by simulations, as well...

The relationships between the acoustic signal and the modes of the welding pool such as no-keyhole (melt-in), keyhole and cutting in variable polarity plasma arc welding (VPPAW) are investigated. Welch power spectral density (PSD) estimate is used for preprocessing the sound data. A neural network (NN) is used to distinguish the keyhole mode from the cutting mode. The results show that the keyh...

PhotonicsViewsVolume 18, Issue S1 p. 30-31 Metal-JoiningFree Access Laser Keyhole Brazing Energy-efficient brazing using the deep penetration effect in combination with two-dimensional beam oscillation Insa Henze, Corresponding Author Henze [email protected] www.bias.de +49 421 218-58136 BIAS – Bremer Institut für angewandte Strahltechnik GmbH, Klagenfurter Straße 5, 28359 Bremen, GermanySearch for...