Obtaining Superhard Coatings of Cubic Tungsten Carbide under High-speed Plasma Spraying

2020 ◽  
Author(s):  
Alexander Sivkov ◽  
Artur Nassyrbayev ◽  
Dmitriy Nikitin ◽  
Alexander Tsimmerman ◽  
Yuliya Vympina ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Plasma Spraying ◽  
High Speed ◽  
Superhard Coatings

NIROSTA 4305

Alloy Digest ◽  
2002 ◽  
Vol 51 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tungsten Carbide ◽  
Tensile Properties ◽  
High Speed ◽  
High Speed Steel ◽  
Heat Treating ◽  
Austenitic Steels ◽  
High Sulfur Content ◽  
Machined Parts

Abstract NIROSTA 4305 is an austenitic alloy with a high sulfur content. The alloy is typically used for machined parts. As with other austenitic steels, it is necessary to machine with good-quality high-speed steel or tungsten carbide tools. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-854. Producer or source: ThyssenKrupp Nirosta GmbH.

Composite cladded powders for spraying of protective coatings

2019 ◽  
pp. 59-64
Author(s):  
E. Yu. Gerashchenkova ◽  
T. I. Bobkova ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Tungsten Carbide ◽  
Gas Phase ◽  
High Speed ◽  
Protective Coatings ◽  
Powder Materials ◽  
Nanosized Particles

The paper presents results of the development of technology for producing cladded and surfacealloyed powder materials. High-speed mechanosynthesis of matrix powders of FeCrAl and solid nanosized particles of tungsten carbide occurs in a disintegrator in the presence of an active gas phase (nitrogen).

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.

scholarly journals Coatings of Carbide-Metal Systems (Cr3C2-NiCr and WC-Co-Cr) Deposited by High-Velocity Atmospheric Plasma Spraying from Specially Modified Fine-Grained Powders

2018 ◽  
Vol 1 (1) ◽  
pp. 18-23
Author(s):  
Vadim Verlotski ◽  
Keyword(s):  
Plasma Spraying ◽  
High Speed ◽  
Plasma Deposition ◽  
Thermal Spraying ◽  
Atmospheric Plasma ◽  
Metal Particles ◽  
Fine Grained ◽  
Plasma Torches ◽  
Carbide Coatings ◽  
Gas Tight

In this article, the author poses and responds to a provocative question that has practically ceased to be asked in the field of thermal spraying of carbide coatings: Is the current worldwide trend of using only unmelted metal particles to form coatings (HVOF, HVAF and cold spray methods) correct, and is the deposition of completely melted powders (plasma spraying methods) really outdated? The results of high-speed plasma deposition of new carbide powders allowed the author to prove that only coatings from molten particles can solve the main problem of such coatings, namely the problem of permeability along the grain boundaries. Through the use of modern Axial III plasma torches combined with optimized fine-grained powders, it has been possible to create Cr3C2-NiCr as well as WC-Co-Cr gas-tight layers.

Properties of tungsten coating deposited onto copper by high-speed atmospheric plasma spraying

2011 ◽  
Vol 414 (1) ◽  
pp. 8-11 ◽  
Author(s):  
Huang Jianjun ◽  
Wang Fan ◽  
Liu Ying ◽  
Jiang Shishou ◽  
Wang Xisheng ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
High Speed ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Tungsten Coating

Controls for Plasma Spraying Based on Plasma Jet Stability Analysis

1998 ◽  
Author(s):  
L. Beall ◽  
Z. Duan ◽  
J. Schein ◽  
J. Heberlein ◽  
M. Stachowicz ◽  
...  
Keyword(s):  
Process Control ◽  
Plasma Spraying ◽  
High Speed ◽  
Small Degree ◽  
Negative Effects ◽  
Microphone Signal ◽  
Jet Length ◽  
Jet Stability ◽  
Control Scheme ◽  
Coating Characteristics

Abstract Despite the fact that plasma spraying has been a widely used technology over the past three decades, industries using this technology still need higher quality products. Presently, only a small degree of process control is used in most plasma spraying systems. Improved process control should lead to more consistent results and higher quality products. We discuss a relatively simple control scheme consisting of a microphone as a primary sensor and a fuzzy logic look-up model indicating the condition of the anode. Selected frequency peaks in the power spectrum of the microphone signal are analyzed online, and the results are correlated with an average jet length obtained from a series of high speed images. The jet length, in turn, is correlated with coating characteristics. A simple feedback control system is proposed which will counteract the negative effects of an eroded anode on coating quality.

Friction of tungsten carbide-cobalt coatings obtained by means of plasma spraying

1991 ◽  
Vol 48 (3) ◽  
pp. 241-248 ◽  
Author(s):  
M. Cartier ◽  
L. McDonnell ◽  
E.M. Cashell
Keyword(s):  
Tungsten Carbide ◽  
Plasma Spraying

scholarly journals Enamel Quality after Debonding: Evaluation by Optical Coherence Tomography

2015 ◽  
Vol 26 (4) ◽  
pp. 384-389 ◽  
Author(s):  
Jorge César Borges Leão Filho ◽  
Ana Karla Souza Braz ◽  
Renato Evangelista de Araujo ◽  
Orlando Motohiro Tanaka ◽  
Matheus Melo Pithon
Keyword(s):  
Optical Coherence Tomography ◽  
Tungsten Carbide ◽  
High Speed ◽  
Adhesive Layer ◽  
Optical Coherence ◽  
Low Speed ◽  
Ceramic Brackets

<p>The aims of this study were to evaluate quantitatively the enamel fractures, adhesive remnants and bracket fragments on enamel after debonding of metal and ceramic brackets, and to quantify the layer of adhesive remnants in depth after two different cleanup procedures. Metal and ceramic brackets were bonded on 120 human incisors and then debonded using two different techniques with Side Cutter (SC) and Anterior Bracket Removal plier (ABR). After this, a high-speed tungsten carbide finishing bur or a low-speed tungsten carbide finishing bur was used. The debonded samples were submitted to enamel assessment with optical coherence tomography (OCT). In sequence, two different methods of removing the remaining adhesive (tungsten carbide burs at high and low speed) were performed and at the end of these procedures, the remaining adhesive layer was measured with OCT. The results demonstrated that enamel fractures were observed only in the samples bonded with ceramic brackets, and the type of pliers did not influence the incidence and extent of enamel damage. Moreover, the type of debonding technique (with side-cutting pliers or anterior bracket removal pliers) and the type of bracket did not influence the amount of adhesive remaining after debonding. The burs at low speed removed the remaining adhesive more effectively during cleanup procedures.</p>

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