scholarly journals Plasmatron for Coatings

2019 ◽  
Vol 18 (1) ◽  
pp. 5-10
Author(s):  
V. A. Okovity ◽  
F. I. Panteleenko ◽  
V. V. Okovity ◽  
V. M. Astashinsky
Keyword(s):  
Oxygen Content ◽  
Plasma Torch ◽  
Plasma Stream ◽  
Plasma Torches ◽  
Nickel Chromium ◽  
Material Deposition ◽  
Material Utilization ◽  
Sufficient Strength ◽  
Aluminum Yttrium ◽  
Made In

The paper analyzes reasons for application of plasma torches of special design for deposition of heat-resistant layers of thermal barrier coatings that contribute to minimum oxygen content in the zone of spraying. It contains detailed description of design for a plasma torch with a nozzle that allows better protection of a plasma stream against atmospheric exposure.Heated inert gas (Ar) is fed inside the nozzle along its walls through holes in its end part. Air around a plasma jet is displaced, additional compression of the plasma occurs and due to this oxygen content is decreased in a coating and efficiency of material deposition is increased. An additional use of a tungsten insert in an electronic node makes it possible to create a pair of tungsten – tungsten in an electrode assembly and the life of the electrode assembly will be increased due to high erosion resistance, electrical conductivity, thermal conductivity and sufficient strength in 2–2.5 times while increasing spray performance through toughening regimes. The paper presents testing results of the developed plasma torch and its prototype for duration of continuous operation and intensity at 500 A current, 70 V voltage, nitrogen flow rate of 45 l/min (standard mode for deposition of oxide ceramics). Coatings from nickel–chromium–aluminum–yttrium powder have been obtained while using plasma torches with the same parameters of deposition and a comparative analysis of the technological properties have been made in the paper. The developed plasma torch has more qualitative characteristics of subsurface plasma coatings: increase in adhesive strength – by 1.4 times, material utilization ratio – by 1.3 times, micro-hardness – by 1.3 times, porosity decrease – by 2.3 times.

MULTIMET (N-155)

Alloy Digest ◽  
1961 ◽  
Vol 10 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
Age Hardening ◽  
Nickel Chromium ◽  
Cobalt Nickel ◽  
Temperature Performance ◽  
High Oxidation ◽  
Scaling Resistance ◽  
Made In

Abstract MULTIMET alloy is cobalt-nickel-chromium-iron austenitic alloy having high oxidation and scaling resistance along with good high-temperature properties. It tends to work harden but does not respond significantly to age-hardening. It is made in a wrought grade (0.08-0.16% carbon) and a casting grade (0.20% max. carbon). This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SS-28. Producer or source: Haynes Stellite Company. Originally published May 1955, revised December 1961.

GLOBAL ANALYSIS OF THE AIRCRAFT STRUCTURE AND ITS APPLICATION TO THE PRELIMINARY DESIGN STAGE

Aviation ◽  
2005 ◽  
Vol 9 (3) ◽  
pp. 29-35
Author(s):  
Jerzy Bakunowicz ◽  
Tomasz Kopecki
Keyword(s):  
Numerical Model ◽  
Global Analysis ◽  
Economic Factor ◽  
Computer Application ◽  
Local Analysis ◽  
Design Stage ◽  
Preliminary Design ◽  
Preliminary Design Stage ◽  
Sufficient Strength ◽  
Made In

Modern aircraft safety depends on sufficient strength and rigidity of the structure. This must sustain with lightest possible weight, because any excess mass has not only detrimental effect upon the performance but also is significant economic factor. The most rational way to achieve the proper structure seems to be global analysis commenced in the preliminary design stage already. The analysis outcomes provide base for local analysis of the details led parallel. Any revisions more or less relevant can be made in the numerical model with very expensive prototype changes avoiding. The paper illustrates efficiency of the airframe structure global analysis. As examples the aircrafts still in service but designed without computer application were chosen. The finite elements numerical model of each was created and some critical in-flight load cases were simulated.

A simplified method for determining the P50 of blood

1975 ◽  
Vol 38 (6) ◽  
pp. 1140-1142 ◽  
Author(s):  
B. W. Kirk ◽  
M. B. Raber ◽  
K. R. Duke
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Content ◽  
Whole Blood ◽  
Normal Subjects ◽  
Blood Gas ◽  
Inexpensive Method ◽  
Ph Measurements ◽  
Simplified Method ◽  
Very High ◽  
Made In

A method to determine the P50 of whole blood is described using a modified American Optical reflectance oximeter, pump, and membrane tonometer, together with PO2, PCO2, and pH measurements in a standard blood gas machine. Determinations of P50 were made in 66 patients and normal subjects and in two situations where P50 was very low and very high. The results were compared to oxygen saturations calculated from measured oxygen content. The directly determined oxygen saturation agreed with the assumed saturation of 50 per cent in the oximeter within 0.5 per cent. The apparatus appears to be a simple and relatively inexpensive method to obtain P50 as long as blood carboxyhemoglobin or methemoglobin contents are not elevated.

TRIBOLOGICAL PROPERTIES OF Al2O3 + TiO2 COATINGS MANUFACTURED BY PLASMA SPRAYING

Tribologia ◽  
2019 ◽  
Vol 283 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Leszek ŁATKA ◽  
Aneta NIEMIEC ◽  
Monika MICHALAK ◽  
Paweł SOKOŁOWSKI
Keyword(s):  
Plasma Spraying ◽  
Dry Friction ◽  
Plasma Torch ◽  
Spray Parameters ◽  
Good Adhesion ◽  
Spray Distance ◽  
Compact Structure ◽  
Tio2 Coatings ◽  
Made In ◽  
Ball On Disc

In the paper the results of tribological, microscopic, and mechanical research of Al2O3 + TiO2 coatings manufactured by plasma spraying are presented. The feeding material was a powder Al2O3 + 13 wt.% TiO2 (Metco 6221, OerlikonMetco) with grain size – 45 ± 15 μm. The cylinder substrates made from stainless steel (X5CrNi18-10) had a diameter equal to 25 mm and 2 mm of thickness. The variable spray parameters were plasma torch velocity in terms of substrate and spray distance. The morphology of obtained coatings was tested by scanning electron microscope (SEM), and the microstructure was investigated by light optical microscopy (LOM) and SEM. The results of mechanical properties examinations revealed the dependence of the microhardness and fracture toughness on the spray parameters. Tribological examinations were made in the ball-on-disc mode in technical dry friction conditions. Two loads were used, 5 N and 10 N. Based on the carried out tests, it could be concluded that a shorter spray distance and a reduction of the torch velocity allows one to achieve a more compact structure, which is characterized by good adhesion at the coating-substrate interface (in range from 11 to 14 MPa) and good wear resistance.

Theoretical Prediction of the Effect of Coil Configuration on Gas Mixing in an Inductively Coupled Plasma Torch

1987 ◽  
Vol 98 ◽  
Author(s):  
John W. Mckelliget ◽  
Nagy El-Kaddah
Keyword(s):  
Reaction Kinetics ◽  
Inductively Coupled Plasma ◽  
Plasma Torch ◽  
Coil Design ◽  
Potential Equation ◽  
Analysis And Design ◽  
Inductively Coupled ◽  
Plasma Torches ◽  
Coil Geometry ◽  
Electromagnetic Vector Potential

ABSTRACTA mathematical model for the analysis and design of inductively coupled plasma torches Is presented. The model is based upon a solution of the electromagnetic vector potential equation and is capable of predicting the two-dimensional velocity, temperature, and electromagnetic fields as well as the reaction kinetics inside the torch for any axi-symmetric coil configuration. The model is used to study the effect of coil geometry on the thermal decomposition of silicon tetrachloride to silicon. The coil geometry Is found to affect both the temperature field and the flow field and to have a significant effect on the reaction kinetics in the torch. It is demonstrated that through fundamental changes in the coil design It is possible to control the location of the reaction zone and to prevent silicon deposition on the wall of the reactor.

scholarly journals Design of a new gas-dynamic stabilization system for a metal-cutting plasma torch

2021 ◽  
Vol 2094 (4) ◽  
pp. 042075
Author(s):  
I Yu Matushkina ◽  
S V Anakhov ◽  
Yu A Pyckin
Keyword(s):  
Velocity Distribution ◽  
Cross Section ◽  
Plasma Torch ◽  
Metal Cutting ◽  
Evaluation Method ◽  
Dynamic Stabilization ◽  
Stabilization System ◽  
Plasma Torches ◽  
Gas Dynamic ◽  
The Cross

Abstract The analysis of the influence of various design solutions of the gas-dynamic stabilization system in plasma torches for cutting metals on the efficiency of equalizing the velocities of gas flows along the cross-section of the gas path is carried out. It is noted that the efficiency evaluation method developed by the authors should be based on the calculation of the uniformity of the gas flow velocity distribution over the cross-section of the gas-air path of the plasma torch. A vortex stabilization system using two swirlers is proposed. The effect of improving the reliability and quality of plasma cutting is shown. The results of the efficiency studies for the proposed system of gas-vortex stabilization in metal-cutting plasma torches are presented. The calculating results of equalization coefficients for the velocity distribution in different parts of the gas-dynamic stabilization system in the plasma torch are presented. Based on the results of the calculations, a constructive optimization of the gas-air path in the plasma torch was performed. The experimentally obtained advantages of the new upgraded plasma torch in terms of the gas-vortex stabilization efficiency are demonstrated. The effects of improved cutting quality and reduced nozzle wear in the new plasma torch are shown. This is due to the higher degree of the plasma arc stabilization in the new plasma torch, which leads to a decrease in its oscillations, and, consequently, to an increase in the efficiency of the cutting process.

INFLUENCE OF MODE AND GEOMETRIC CHRATERISTICS ON HIGHT-FREQUENCY INDUCTIVE PLASMA TORCH WITH REVERSE VORTEX FLOW

2019 ◽  
pp. 77-82
Author(s):  
Sergey Serbin ◽  
Аnna Mostipanenko
Keyword(s):  
High Frequency ◽  
Plasma Torch ◽  
Vortex Flow ◽  
Coal Dust ◽  
Air Plasma ◽  
Plasma Torches ◽  
Structure Of Flow ◽  
Wide Range ◽  
High Frequency Electromagnetic Field ◽  
Numerical Simulation Methods

The analysis of aerodynamic and heat structure of flow in high-frequency inductive plasma torch has been carried out. The range of plasma torch power is measured in dozens of kilowatts. The numerical simulation methods of the turbulent flow in the plasma torch affected by high frequency electromagnetic field without considering the chemical kinetics are used during the research. The data of temperature field and induced current density in the plasma torch depending on current amperage and frequency are obtained. Also, these data are obtained depending on the flow scheme in the operated on argon and air plasma torches. The inductive plasma torches can be applied to solve a wide range of tasks such as activation of coal-dust mixture with its further gasification, coating process for the stabilization of combustion processes as well as for the recycling processes at the mobile seaport recycling complexes. The calculations demonstrated convincingly the advantage of the operation of plasma torches with reverse vortex flow over plasma torches with “direct” vortex flow. Moreover the obtained data allow executing the assessment of thermal efficiency of inductive plasma jet and obtaining its optimal operational modes.

PLASMA FLOW CHARACTERISTICS INSIDE THE SUPERSONIC D.C. PLASMA TORCH

2005 ◽  
Vol 14 (02) ◽  
pp. 225-238 ◽  
Author(s):  
X. Q. YUAN ◽  
T. Z. ZHAO ◽  
W. K. GUO ◽  
P. XU
Keyword(s):  
Plasma Flow ◽  
Plasma Torch ◽  
Energy Transport ◽  
Flow Characteristics ◽  
Viscous Effects ◽  
Supersonic Plasma ◽  
Arc Current ◽  
Velocity Pressure ◽  
Laminar State ◽  
Made In

A magnetohydrodynamic (MHD) model, which describes supersonic plasma flow inside the torch, is presented in this paper. It is a two-dimensional model but includes the K -epsilon model of turbulence, the gas viscous effects and compressible effects. The PHOENICS software is used for solving the governing equations, i.e. the conservation equations of mass, momentum, and energy together with the equations describing the K -epsilon model of turbulence. The calculated arc voltages and gas inflow rates are consistent with the experimental results when arc current and the working gas are the same as experiment. The plasma flow characteristics inside the supersonic plasma torch are analyzed in detail. Temperature, velocity, pressure and Mach number contours are presented to show the flow characteristics. Comparisons between turbulent and laminar models are made in detail also, and the results show the turbulent enhanced momentum and energy transport inside the supersonic plasma torch has little effect on the whole discharge area. The plasma flow inside the supersonic torch is mainly in the laminar state.

Blood Oxygen Capacity

1968 ◽  
Vol 14 (3) ◽  
pp. 253-261 ◽  
Author(s):  
M Clauvel ◽  
K Schwartz
Keyword(s):  
Oxygen Content ◽  
Human Blood ◽  
Special Care ◽  
Blood Oxygen ◽  
Hemoglobin Content ◽  
Oxygen Capacity ◽  
Water Saturated ◽  
And Storage ◽  
Made In

Abstract During determination of the oxygen capacity of blood by the Van Slyke method (1), the following adaptations were made in order to reduce errors: (1) Blood was equilibrated with water-saturated air in a siliconized tonometer. (2) The determination of the oxygen content of the sample was carried out immediately after equilibration. (3) Triton was used instead of saponin in the ferricyanide reagent. (4) Special care was taken in the preparation and storage of the dithionite reagent, which should be prepared fresh daily and stored in the dark at 4°. The hemoglobin content and oxygen capacity, measured by the modified technic, were compared in a series of 36 samples of human blood.

Sign in / Sign up

Export Citation Format

Share Document