The lifetime of tungsten cathodes used in plasma spray torches is limited by processes leading to a loss of cathode material. It was reported in the literature that the mechanism of their erosion is the evaporation. A model of the ionization layer of a cathode is developed to study the diffusive transport of evaporated tungsten atoms and tungsten ions produced due to ionization by electron impact in a background argon plasma.
Self-consistent Cathode-Plasma Coupling and Role of the Fluid Flow Approach in Torch Modelling - Dataset
The data set is related to a two-dimensional and stationary magneto-hydrodynamic model of a plasma spray torch operated with argon, which is developed to predict the plasma properties in a steady operating mode. The model couples a submodel of a refractory cathode and its non-equilibrium boundary layer to a submodel of the plasma in local thermodynamic equilibrium in a self-consistent manner. The Navier-Stokes equations for a laminar and compressible flow are solved in terms of low- and high-Mach number numerical approaches.
The hairline plasma jet (hairlINePlasma) is a cold atmospheric pressure plasma source mainly for biological and medical applications. hairlINePlasma uses the physical effect of negative dc corona discharges and produces a nanosecond self-pulsed microplasma with a very thin plasma filament. The Plasma filament has a diameter of about 30 µm and a length of up to 3 cm. Due to this geometrical features, hairlINePlasma is particularly suitable for the treatment of microscopic cavities and the localized functionalization of conductive surfaces.
This plasma source is a commercial welding power source produced by Miller Electric Manufacturing Co., Appleton / USA. This welding system is precise, digitally controlled and software-driven. Several different wire feeding and operator interface options are available and configurable to desired application. The welding system allows a simple method that controls arc length for pulse processes and wetting action and allows changing weld programs to take advantage of up to eight programs of Multi-MIG welding process capabilities.
A plasma treatment device having an electrode arrangement (3) for generating a plasma in a supplied gas stream. The electrode arrangement has at least one movably mounted electrode. The plasma is preferably a cold atmospheric pressure plasma and can be generated so as to vary in location by means of movement of the at least one electrode.
In this work we present for the first time a unified model of a low-current short-length arc between copper electrodes. The model employs one-dimensional fluid description of the plasma in argon and copper vapour at atmospheric pressure and the heat transfer in the electrodes made of copper. The solution of the particle and energy conservation of electrons and heavy particles is coupled with the solution of the Poisson equation, from which the self-consistent electric field is obtained. The operation of the non-refractory cathode is based on thermo-field emission.
This dataset contains plasma parameters of microarcs generated between a cooled copper anode and a ceriated tungsten cathode by means of a one-dimensional unified non-equilibrium model for gap lengths between 15 and 200 µm and current densities from 2x10^5 up to 10^6 A/m^2. The data show that the decrease of the gap length down to a few tens of micrometers for a given current density results in a progressive shrinking of the quasineutral bulk in the microplasma and its complete disappearance.
Recent research of gas metal arc welding (GMAW) has proven that the sheath voltage dominates the total voltage fall in the current circuit and delivers most of the energy, which is finally transferred to the wire and the weld pool. This data set provides the results for droplet temperatures and the energy delivered to the wire anode in comparison with the sheath voltages. These quantities have been studied experimentally for a typical pulsed GMAW process in the one drop per pulse mode for mild steel under Ar with 2.5% CO2 with different peak currents from 350 to 650 A.
The relation between the voltage and the arc length in gas metal arc welding (GMAW) is an important characteristic. It depends on a complex distribution of the electric conductivity along the current path and does not depend on the arc length only. Based on electric measurements and the arc length determination from high-speed arc images, a simplified electrical model is introduced for a pulsed GMAW process. It shows the relation of voltage, current, arc length and free wire length and considers also their temporal evolution during the process in particular during the high-current phase.