Method for Identifying In-Flight Particles based on Digital Image Technologies in Thermal Spraying

2021 ◽  
Author(s):  
Yijun Yao ◽  
Shaowu Liu ◽  
Marie-Pierre Planche ◽  
Sihao Deng ◽  
Hanlin Liao
Keyword(s):  
Thermal Spray ◽  
Digital Image ◽  
Thermal Spraying ◽  
Imaging Systems ◽  
Tracking Problem ◽  
Coating Performance ◽  
Image Frame ◽  
Thermal Spray Processes

Abstract In thermal spray processes, the characteristics of in-flight particles (velocity and temperature) have a significant effect on coating performance. Although many imaging systems and algorithms have been developed for identifying and tracking in-flight particles, most are limited in terms of accuracy. One key to solving the tracking problem is to get an algorithm that can distinguish different particles in each image frame. As the study showed, when noise and interference are treated, particles are more readily identified in the background, leading to more accurate size and position measurements with respect to time. This approach is demonstrated and the results discussed.

scholarly journals Advanced Coatings by Thermal Spray Processes

Technologies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 79
Author(s):  
Joshi ◽  
Nylen
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
High Performance ◽  
Fine Particles ◽  
Thermal Spraying ◽  
Atmospheric Plasma ◽  
Processing Temperature ◽  
Diverse Application ◽  
Liquid Feedstock ◽  
Thermal Spray Processes

Coatings are pivotal in combating problems of premature component degradation in aggressive industrial environments and constitute a strategic area for continued development. Thermal spray (TS) coatings offer distinct advantages by combining versatility, cost-effectiveness, and the ability to coat complex geometries without constraints of other in-chamber processes. Consequently, TS techniques like high-velocity oxy-fuel (HVOF) and atmospheric plasma spray (APS) are industrially well-accepted. However, they have reached limits of their capabilities while expectations from coatings progressively increase in pursuit of enhanced efficiency and productivity. Two emerging TS variants, namely high-velocity air-fuel (HVAF) and liquid feedstock thermal spraying, offer attractive pathways to realize high-performance surfaces superior to those hitherto achievable. Supersonic HVAF spraying provides highly adherent coatings with negligible porosity and its low processing temperature also ensures insignificant thermal ‘damage’ (oxidation, decarburization, etc.) to the starting material. On the other hand, liquid feedstock derived TS coatings, deposited using suspensions of fine particles (100 nm–5 µm) or solution precursors, permits the production of coatings with novel microstructures and diverse application-specific architectures. The possibility of hybrid processing, combining liquid and powder feedstock, provides further opportunities to fine tune the properties of functional surfaces. These new approaches are discussed along with some illustrative examples.

Microstructure and Selected Properties of WC-Co-Cr Coatings Deposited by High Velocity Thermal Spray Processes

2016 ◽  
Vol 246 ◽  
pp. 117-122
Author(s):  
Hanna Myalska ◽  
Krzysztof Szymański ◽  
Grzegorz Moskal
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Liquid Fuel ◽  
Steel Substrate ◽  
Thermal Spraying ◽  
Three Generations ◽  
Thermal Spray Processes ◽  
Spraying Method

Selected information about high velocity thermal spraying method were presented in this article. Three generations of thermal spraying processes based on oxygen with propane mixture, liquid fuel with oxygen and propane with air were characterized. A powder of WC-Co-Cr 86-10-4 was used for coatings deposition on a steel substrate. Four coatings were deposited by different thermal spraying systems such as Diamond Jet, JP 5000, Micro HVOF and HVAF.

Thermal Spray Alternatives for Electroplated Chromium

1996 ◽  
Author(s):  
G. Irons ◽  
W. Kratochvil ◽  
M. Schroeder ◽  
C. Brock
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Spray Coating ◽  
Ceramic Materials ◽  
Thermal Spray Coating ◽  
Waste Products ◽  
Spray Process ◽  
Arc Spray ◽  
Chromium Plating ◽  
Thermal Spray Processes

Abstract Many thermal spray coatings provide excellent wear and corrosion resistance, while providing die same surface finish offered by chromium plating. In the past, the choice between thermal spraying or plating was usually based on part size, area to be coated, cost and familiarity with one or the other method. Today, the thermal spray processes are showing greater popularity due to: ♦ New thermal spray processes and coatings with better properties ♦ Increased chromium plating costs due to stricter regulations on the process and the disposal of its waste products ♦ The closing of chromium plating facilities Thermal spraying offers an opportunity to select a coating from a wide variety of processes and materials that will meet the specific requirements of each application. While this may cause some difficulty in selecting the optimum coating, the selected thermal spray coating often has superior propolies and/or lower cost compared to chromium plating. The highest quality coatings are sprayed by the HVOF process, many with carbide containing materials. Dense plasma grayed ceramic materials offer good wear resistance plus elevated temperature capability. The most economical replacements for chromium plate are applied by the two-wire arc spray process. This paper examines the properties and costs of eight different dismal sprayed coatings and compares them with electroplated chromium.

Towards a Better Control of Thermal Spray Processes

1998 ◽  
Author(s):  
C. Moreau
Keyword(s):  
Thermal Spray ◽  
Intelligent Control ◽  
Control Strategy ◽  
Thermal Spraying ◽  
The State ◽  
Basic Knowledge ◽  
Current Sensing ◽  
The Future ◽  
Consistent Manner ◽  
Thermal Spray Processes

Abstract Developing and using efficient controls for thermal spray processes is essential to produce coatings in a more consistent manner day after day. This paper discussed the different approaches that can be used, today or in the future, to better control spray processes. The various steps or sub-processes involved in thermal spraying are first reviewed identifying the key parameters that can be monitored and controlled. An overview of current sensing techniques and those under development for probing the state of these key parameters will then be presented. Finally, different control approaches will be reviewed looking at the basic knowledge and models required to implement an efficient and intelligent control strategy for thermal spray processes.

Microprobe X-ray studies of thermal spray coatings

2010 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
P. D. Quinn ◽  
J. F. W. Mosselmans ◽  
D. G. McCartney ◽  
D. Zhang
Keyword(s):  
Thermal Spray ◽  
Protective Coatings ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Extreme Conditions ◽  
Structural Variations ◽  
Coating Performance ◽  
X Ray ◽  
Spray Coatings

Thermal spraying is emerging as the leading route for the deposition of protective coatings onto engineering components to improve operation under extreme conditions of temperature, wear or corrosion. Detailed microstructural assessment is a key element in improving coating performance, and this study demonstrates the application of microfocus X-ray techniques to the determination of elemental and structural variations in the coatings.

Thermal Spraying of Wear and Corrosion Resistant Surfaces

2008 ◽  
Vol 384 ◽  
pp. 75-98 ◽  
Author(s):  
Bernhard Wielage ◽  
Thomas Lampke ◽  
Thomas Grund
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Base Material ◽  
Thermal Spray Coatings ◽  
Selective Coating ◽  
Spray Coatings ◽  
Wear And Corrosion ◽  
Parameter Field ◽  
Thermal Spray Processes ◽  
Sprayed Coatings

Thermal spraying is one of the most variable and diverse surface coating techniques concerning materials to be processed as well as possible geometries to be coated. The group of thermal spray processes covers a large parameter field to combine nearly each coating with each base material. Thermally sprayed coatings can be applied very evenly and therefore allow to be applied on final-shaped components. Otherwise, if further treatment or finishing is necessary, thermal spray coatings can be processed by grinding or even milling. Masking during the coating process permits the selective coating of specific surface parts or the application of required geometrically structures, e. q. conductor structures. The main application field of thermal spray coatings is the (combined) wear and corrosion protection of selected component parts.

Particle-in-flight monitoring in thermal spray processes

2010 ◽  
Vol 205 (4) ◽  
pp. 1092-1095 ◽  
Author(s):  
M. Doubenskaia ◽  
D. Novichenko ◽  
A. Sova ◽  
D. Pervoushin
Keyword(s):  
Thermal Spray ◽  
Thermal Spray Processes

Simulation of Thermal Spray Process Based on Particle Tracing Method

2000 ◽  
Author(s):  
K. Wada ◽  
M. Ito ◽  
M. Takahashi ◽  
K. Takaishi
Keyword(s):  
Thermal Spray ◽  
Coating Thickness ◽  
Computer Aided Design ◽  
Simulation Method ◽  
Work Piece ◽  
Stainless Steel 316L ◽  
Particle Tracing ◽  
Computer Aided ◽  
Thermal Spray Processes ◽  
Tracing Method

Abstract As applications of thermal spray processes are expanding, the importance of computer-aided design systems and computer-aided engineering systems for these processes has been growing. The principal objective of this study is to propose a new analytic method for the prediction of coating thickness and deposition efficiency. This method is called the particle tracing method and is based on the Monte Carlo simulation method. In order to evaluate the validity of this model, several tests were carried out. The same stainless steel 316L layers coated by the HP/HVOF process (TAFA JP-5000) were used throughout each test. First, spray patterns were observed which had formed on flat-plate specimens from various spray gun angles. Coating thickness distributions on several curved planes were consequently investigated. Finally, the coating process for a blade of a compressor in a gas turbine was simulated. In the right of the results of these experiments, it is summarized that the calculated values of the coating thickness obtained by our method are in good agreement with experimental values. The accuracy is within 10% of the maximum thickness value in each specimen, except for at the edge of the work-piece. In conclusion, the particle-tracing method can be applied to the fundamental analytic model in the CAD or CAE system for thermal spray processes.

Comprehensive Methods for Studying Microinhomogeneity in Thermal Spray Coatings with Amorphous-Crystalline Structure

1998 ◽  
Author(s):  
G. Grigorenko ◽  
A. Borisova
Keyword(s):  
Thermal Spray ◽  
Crystalline Structure ◽  
Structural Phase ◽  
Thermal Spraying ◽  
Integrated Approach ◽  
Thermal Spray Coatings ◽  
Chemical Heterogeneity ◽  
New Approach ◽  
X Ray ◽  
Spray Coatings

Abstract An integrated approach was developed for investigation of thermal spray coatings with the amorphous-crystalline structure. The new approach combines methods of metallography, differential thermal and X-ray phase analysis, scanning electron microscopy and X-ray microanalysis. This makes it possible to reveal structural, phase and chemical heterogeneity, determine the degree of amorphization of coatings, temperature and heat of crystallization of the amorphous phase during heating. The new integrated approach was used to study amorphous-crystalline coatings of the Ni-P, Fe-Ni-B and Fe-B systems produced by thermal spraying.

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