Direct dynamic synthesis of nanodispersed titanium nitride in a high-speed pulse electroerosion plasma jet

2008 ◽  
Vol 30 (5) ◽  
pp. 311-316 ◽  
Author(s):  
A. A. Sivkov ◽  
E. P. Naiden ◽  
D. Yu. Gerasimov
Keyword(s):  
Titanium Nitride ◽  
High Speed ◽  
Plasma Jet ◽  
Dynamic Synthesis

scholarly journals High-Speed Video Analysis of the Process Stability in Plasma Spraying

2021 ◽  
Author(s):  
K. Bobzin ◽  
M. Öte ◽  
M. A. Knoch ◽  
I. Alkhasli ◽  
H. Heinemann
Keyword(s):  
Plasma Spraying ◽  
High Speed ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Time Dependent ◽  
Acquisition Time ◽  
Fast Fourier Transformation ◽  
Frequency Spectra ◽  
Dependent Signal ◽  
The Stability

AbstractIn plasma spraying, instabilities and fluctuations of the plasma jet have a significant influence on the particle in-flight temperatures and velocities, thus affecting the coating properties. This work introduces a new method to analyze the stability of plasma jets using high-speed videography. An approach is presented, which digitally examines the images to determine the size of the plasma jet core. By correlating this jet size with the acquisition time, a time-dependent signal of the plasma jet size is generated. In order to evaluate the stability of the plasma jet, this signal is analyzed by calculating its coefficient of variation cv. The method is validated by measuring the known difference in stability between a single-cathode and a cascaded multi-cathode plasma generator. For this purpose, a design of experiment, covering a variety of parameters, is conducted. To identify the cause of the plasma jet fluctuations, the frequency spectra are obtained and subsequently interpreted by means of the fast Fourier transformation. To quantify the significance of the fluctuations on the particle in-flight properties, a new single numerical parameter is introduced. This parameter is based on the fraction of the time-dependent signal of the plasma jet in the relevant frequency range.

Integrated Optimal Design of Planar Mechanisms Using Fuzzy Theories

1989 ◽  
Author(s):  
A. K. Dhingra ◽  
S. S. Rao
Keyword(s):  
Nonlinear Programming ◽  
High Speed ◽  
Integrated Approach ◽  
Problem Formulation ◽  
Optimization Techniques ◽  
Motion Path ◽  
Programming Formulation ◽  
Planar Mechanisms ◽  
Dynamic Synthesis ◽  
Motion Characteristics

Abstract A new integrated approach to the design of high speed planar mechanisms is presented. The resulting nonlinear programming formulation combines both the kinematic and dynamic synthesis aspects of mechanism design. The multiobjective optimization techniques presented in this work facilitate the design of a linkage to meet several kinematic and dynamic design criteria. The method can be used for motion, path, and function generation problems. The nonlinear programming formulation also permits the imposition of constraints to eliminate solutions which possess undesirable kinematic and motion characteristics. To model the vague and imprecise information in the problem formulation, the tools of fuzzy set theory have been used. A method of solving the resulting fuzzy multiobjective problem using mathematical programming techniques is presented. The outlined procedure is expected to be useful in situations where doubt arises about the exactness of permissible values, degree of credibility, and correctness of statements and judgements.

Synthesizing Cubic Diamond Crystal Using DC Plasma Jet CVD

2019 ◽  
Vol 825 ◽  
pp. 71-76
Author(s):  
Hiromichi Toyota ◽  
Xia Zhu ◽  
Ryoya Shiraishi ◽  
Kazuto Nakajima ◽  
Yukiharu Iwamoto ◽  
...  
Keyword(s):  
High Speed ◽  
Catalytic Effect ◽  
Plasma Jet ◽  
Methanol Solution ◽  
Arc Plasma ◽  
Plasma Power ◽  
Experimental Conditions ◽  
Diamond Crystals ◽  
Dc Arc ◽  
Solution Gas

Diamond crystals are successfully synthesized by irradiating DC arc plasma jet to the substrate set in a methanol solution. It is the important procedure to preheat the substrate by inert Ar plasma jet before introducing the methanol solution gas to the plasma jet gun. The effects of two experimental conditions, the incident power and the substrates, are investigated. In the case of the Si substrate, cubic crystalline diamond grains of same size are synthesized at the plasma power of 470W. High speed hetero epitaxy is expected by using this method. In the case of the tungsten carbide substrate, diamond crystals and carbon nanotubes are simultaneously synthesized at the plasma power of 260W. The catalytic effect of Co binder in the substrate may cause the chemical reaction of the nanotube synthesis.

scholarly journals Subpixel Temperature Measurements in Plasma Jet Environments Using High-Speed Multispectral Pyrometry

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Tairan Fu ◽  
Jiangfan Liu ◽  
Minghao Duan ◽  
Sen Li
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Leading Edge ◽  
Plasma Jet ◽  
Temperature Measurements ◽  
Convective Heating ◽  
Small Data ◽  
Supersonic Plasma ◽  
Supersonic Plasma Jet ◽  
Spatial Temperature

A high-speed (2 kHz) near-infrared (1.0–1.65 μm) multispectral pyrometer was used for noninvasive measurements of the subpixel temperature distribution near the sharp leading edge of a wing exposed to a supersonic plasma jet. The multispectral pyrometer operating in the field measurement mode was able to measure the spatial temperature distribution. Multiple spectra were used to determine the temperature distributions in the measurement region. The spatial resolution of the multispectral pyrometer was not restricted to one “pixel” but was extended to subpixel accuracy (the temperature distribution inside one pixel in the image space corresponding to the point region in the object space). Thus, this system gives high-speed, multichannel, and long working time spatial temperature measurements with a small data stream from high-speed multispectral pyrometers. The temperature distribution of the leading edge of a ceramic wing was investigated with the leading edge exposed to extreme convective heating from a high-enthalpy plasma flow. Simultaneous measurements with a multispectral pyrometer and an imaging pyrometer verify the measurement accuracy of the subpixel temperature distribution. Thus, this multispectral pyrometry can provide in situ noninvasive temperature diagnostics in supersonic plasma jet environments.

Titanium nitride deposition on hardened high speed steel by reactive magnetron sputtering

1990 ◽  
Vol 190 (2) ◽  
pp. 265-277 ◽  
Author(s):  
M.Y. Al-Jaroudi ◽  
H.T.G. Hentzell ◽  
S.E. Hörnström ◽  
A. Bengtson
Keyword(s):  
Magnetron Sputtering ◽  
Titanium Nitride ◽  
High Speed ◽  
High Speed Steel ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron

Basic Characteristics of In-Liquid Plasma Jet and Electrode Damage

2017 ◽  
Vol 749 ◽  
pp. 76-80
Author(s):  
Xia Zhu ◽  
Taisuke Satoh ◽  
Hiromichi Toyota ◽  
Shinfuku Nomura ◽  
Yukiharu Iwamoto ◽  
...  
Keyword(s):  
High Speed ◽  
Arc Discharge ◽  
Basic Research ◽  
Plasma Jet ◽  
Waste Incineration ◽  
Practical Method ◽  
Discharge Voltage ◽  
Coupled Analysis ◽  
Temperature Plasma ◽  
Jet Characteristics

The most progress towards a practical method of fusing municipal waste incineration ash has been in the use of a plasma jet that employs arc discharge, a form of thermal plasma. However, a remaining problem is that stable plasma generation is prevented by melting of the nozzle of the plasma-jet torch by the high-temperature plasma flow. With the objective of developing high-speed fusion treatment for waste materials using an in-liquid plasma jet, basic research was conducted on plasma stability and the durability of plasma-jet torches, including electrodes and nozzles. Basic plasma jet characteristics such as the discharge voltage, current, and power value at the time of plasma jet generation were investigated experimentally. The relationship between the temperature distribution near the tip of a plasma jet torch and electrode damage was investigated by fluid-heat coupled analysis using the finite element method.

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