scholarly journals Recent Developments in the Research of Splat Formation Process in Thermal Spraying

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Kun Yang ◽  
Min Liu ◽  
Kesong Zhou ◽  
Changguang Deng
Keyword(s):  
Formation Process ◽  
Thermal Spraying ◽  
Industrial Applications ◽  
Splat Formation ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Recent Developments ◽  
The Individual ◽  
Free Falling ◽  
Future Work

Thermal spraying is a well-established surface modification technology which has been widely used in industrial applications. As the coating properties were mainly determined by the flattening nature of each splat, much attention has been increasingly paid to the study on the splat formation process of thermal sprayed particles. This paper is concerned with the development in the research of the splat formation process of the individual splat deposited by thermal spraying during the past few decades, including the experimental and numerical simulations up to today; some classical splashing models were also reviewed. As a simulation of the actual thermal spray process, the development of the flattening behavior of free falling droplet has been mentioned as well. On the basis of the current investigation, some recommendations for the future work have been advised.

Grey modeling for thermal spray processing parameter analysis

2020 ◽  
Vol 10 (3) ◽  
pp. 265-279 ◽  
Author(s):  
Meimei Liu ◽  
Yicha Zhang ◽  
Wenjie Dong ◽  
Zexin Yu ◽  
Sifeng Liu ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Processing Parameters ◽  
Industrial Applications ◽  
Parameter Analysis ◽  
Processing Parameter ◽  
Content Type ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Non Linear ◽  
Spray Processing

PurposeThis paper presents the application of grey modeling for thermal spray processing parameter analysis in less data environment.Design/methodology/approachBased on processing knowledge, key processing parameters of thermal spray process are analyzed and preselected. Then, linear and non-linear grey modeling models are integrated to mine the relationships between different processing parameters.FindingsModel A reveals the linear correlation between the HVOF process parameters and the characterization of particle in-flight with average relative errors of 9.230 percent and 5.483 percent for velocity and temperature.Research limitations/implicationsThe prediction accuracies of coatings properties vary, which means that there exists more complex non-linear relationship between the identified input parameters and coating results, or more unexpected factors (e.g. factors from material side) should be further investigated.Practical implicationsAccording to the modeling case in this paper, method has potential to deal with other diverse modeling problems in different industrial applications where challenge to collecting large quantity of data sets exists.Originality/valueIt is the first time to apply grey modeling for thermal spray processing where complicated relationships among processing parameters exist. The modeling results show reasonable results to experiment and existing processing knowledge.

Laser-Induced Surface Texturing of Metal or Organic Substrates for Structural Adhesive Bonding

2016 ◽  
Vol 879 ◽  
pp. 390-395
Author(s):  
Sophie Costil ◽  
Robin Kromer ◽  
Sébastien Gojon ◽  
Emilie Aubignat ◽  
Christophe Verdy ◽  
...  
Keyword(s):  
Laser Beam ◽  
Thermal Spray ◽  
Adhesive Bonding ◽  
Surface Texturing ◽  
Thermal Spraying ◽  
Cold Spraying ◽  
Adhesive Bond ◽  
Organic Substrates ◽  
Thermal Spray Process ◽  
Spray Process

Laser-matter interaction is commonly described regarding three main factors: laser beam, materials and environment. Conversion of absorbed energy via collision process into heat is the most important effect that occurs during laser interaction. Short-pulsed laser beam induces fast transition from the overheated liquid to a mixture of vapor and drops which allows the ablation of micrometric layers. Specific patterns can then be achieved using scanning and automation technology also called laser texturing. New materials with specific properties such as endurance life and/or lower environmental impact attract emerging technologies such as thermal spraying. However, adhesive bond strengths have to be high enough to play a key role in surface properties. A clean surface to enhance mechanical interlocking is a key element. Mechanical and physico-chemical bond strength for thick coatings elaborated by thermal spray process can then be developed using laser. The aim of the present paper is to show the potential of such emerging treatments through new results using various thermal spray processes (thermal spraying as well as cold spraying). Metal or organic materials were investigated implementing various powders.

Performance of HVOF-Sprayed Carbide Coatings in Aqueous Corrosive Environments

2000 ◽  
Author(s):  
S. Simard ◽  
B. Arsenault ◽  
K. Laul ◽  
M.R. Dorfman
Keyword(s):  
Thermal Spray ◽  
Material Selection ◽  
Corrosive Wear ◽  
Industrial Applications ◽  
Process Technology ◽  
Aqueous Corrosion ◽  
Coating Materials ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Corrosive Environments

Abstract The HVOF technology is well known to provide a wide variety of coating materials having excellent performance characteristics under different aggressive conditions such as wear, erosion by impact of particle and corrosion. Carbides, as a family, constitute a big segment of materials used by the thermal spray industry. Although their material properties may be well known since they are often used in wear or corrosive-wear industrial applications, aqueous corrosion of such coatings are not well characterized. Moreover, thermal spray process technology being in constant evolution, past literature on these coatings may not be directly applicable as newer produced coatings have higher adhesive and cohesive strength. Recent technology allows a better control on density and oxides content that are important parameters to consider for corrosion applications. The success of a coating is related to judicious material selection for various applications. However, the choice of the starting materials for producing a coating is often difficult since there is a lack of data on the corrosion performance of thermal spray coatings. The present paper addresses the performance of various carbide HVOF coatings in terms of corrosion rate and degradation mode in two corrosive environments — HCl and HNO3. Behavior of the coatings is compared using bulk SS316 and SS316 HVOF coating as a benchmark.

scholarly journals Suspension Plasma-Sprayed Thermal Barrier Coatings for Light-Duty Diesel Engines

2019 ◽  
Vol 28 (7) ◽  
pp. 1674-1687 ◽  
Author(s):  
Wellington Uczak de Goes ◽  
Joop Somhorst ◽  
Nicolaie Markocsan ◽  
Mohit Gupta ◽  
Kseniya Illkova
Keyword(s):  
Combustion Chamber ◽  
Functional Properties ◽  
Diesel Engines ◽  
Fuel Efficiency ◽  
Thermal Spraying ◽  
Ceramic Coatings ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Piston Head ◽  
Light Duty

Abstract Demands for improved fuel efficiency and reduced CO2 emissions of diesel engines have been the driving force for car industry in the past decades. One way to achieve this would be by using thermal spraying to apply a thermal insulation layer on parts of the engine’s combustion chamber. A candidate thermal spray process to give coatings with appropriate properties is suspension plasma spray (SPS). SPS, which uses a liquid feedstock for the deposition of finely structured columnar ceramic coatings, was investigated in this work for application in light-duty diesel engines. In this work, different spray processes and materials were explored to achieve coatings with optimized microstructure on the head of aluminum pistons used in diesel engine cars. The functional properties of the coatings were evaluated in single-cylinder engine experiments. The influence of thermo-physical properties of the coatings on their functional properties has been discussed. The influence of different spray processes on coating formation on the complex piston head profiles has been also discussed. The results show that SPS can be a promising technique for producing coatings on parts of the combustion chamber, which can possibly lead to higher engine efficiency in light-duty diesel engines.

Coatings characterization of Ni-based alloy applied by HVOF

2018 ◽  
Vol 90 (2) ◽  
pp. 336-343 ◽  
Author(s):  
José Cabral Miramontes ◽  
Gabriela Karina Pedraza Basulto ◽  
Citlalli Gaona Tiburcio ◽  
Patricia Del Carmen Zambrano Robledo ◽  
Carlos Agustín Poblano Salas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
High Performance ◽  
Thermal Spraying ◽  
Advanced Materials ◽  
Oxide Content ◽  
Coating Materials ◽  
Content Type ◽  
Thermal Spray Process ◽  
Spray Process

Purpose The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304. The aim of this study was to determine the mechanical properties such as hardness and bond strength that these coatings have when the spray distance is varied, as well as the microstructure and phases formed during the thermal spray process. Design/methodology/approach The coatings were applied by HVOF and characterized by scanning electron microscopy, image analysis, X-ray diffraction, microhardness and bond strength to analyze the mechanical properties. Findings The microstructure of the coatings showed low porosity, oxide content and interface contamination in the substrate–coating interface, without the presence of unmolten particles. The microhardness values reached 600 HV for the three spray distances used and the bond strength values reached over 55 MPa. Practical implications The use of coatings on aircraft components is growing dramatically owing to the high costs of advanced materials and the growing lifecycle requirements for high-performance systems, which are taken into account because of the variety of coatings and complexity of environmental factors. Originality/value The originality of this study lies in the development of new coating materials for the manufacture and protection of various turbine components. The value is based on the development of materials and processes to be used to manufacture them.

Theory of Particle Composition Analysis During Thermal Spraying

2000 ◽  
Author(s):  
J. Wilden ◽  
H. Frank
Keyword(s):  
Chemical Composition ◽  
Boundary Conditions ◽  
Particle Temperature ◽  
Thermal Spraying ◽  
Plasma Temperature ◽  
Composition Analysis ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Characteristic Lines ◽  
On Line

Abstract The properties of thermally sprayed coatings significantly depend on the alloy composition and the adjusted process parameters. In addition to the powder certificate it may be useful to analyse the chemical composition of the sprayed powder during the spraying process itself. The principle of composition analysis is similar to the chemical analysis in an ICP plasma but the boundary conditions are more complex because the sprayed powder should not be completely evaporated in a thermal spray process. Nevertheless all thermal spraying processes lead to a certain evaporation of the species and to excitation of atomic states. The transition into the ground state occurs under emission of characteristic lines. The intensity of these lines is influenced by the plasma temperature, the particle temperature, the temperature dependent evaporation rate of the alloying elements and the powder feed rate. In consideration of the boundary conditions and the information from a detailed analysis of the emitted spectra the lines can be used to quantify the chemical composition of the sprayed alloys online. The theory of the principle for on-line analysing the chemical composition will be deduced and the first experimental validation will be presented.

Thermal Spraying of Aluminium Cylinder Bores by the Ford PTWA Spray Process

2006 ◽  
Author(s):  
C. Verpoort ◽  
W. Blume ◽  
R. Ehrenpreis ◽  
M. Silk ◽  
W. Polich ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Nano Material ◽  
Future Demands ◽  
Engine Blocks ◽  
Cylinder Bore

One of the main drivers in the automotive industry is the reduction in fuel consumptions and emissions. In order to achieve these goals, the weight of the engine block as well as the friction in the cylinder bore has to be optimized. This paper describes the FORD PTWA (Plasma Transferred Wire Arc) thermal spray process that protects the aluminum cylinder bore surface against wear by a thermal spray coating. The PTWA technology was originally developed for the application in gasoline V8 engines and it will be shown in this paper how this process can be modified to apply nano-material to produce high-wear resistant, low-friction coatings for highly loaded engine blocks for future demands. A large German BMBF “Nanomobile” Research Program was started in 2005 with 13 partners (DaimlerChrysler, Opel, Porsche, Ford, Gehring, Federal Mogul, GTV Thermal Spray Systems, DURUM, RWTH University and other institutes) in order to develop next generation nano-material coatings for cylinder bores.

Properties of WC-Co Components Produced Using the HVOF Thermal Spray Process

2000 ◽  
Author(s):  
J. Stokes ◽  
L. Looney
Keyword(s):  
Residual Stress ◽  
Thermal Spraying ◽  
Shape Distortion ◽  
Powder Feed Rate ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Hvof Thermal Spray ◽  
Hvof Thermal Spraying ◽  
Hvof Thermal Spray Process ◽  
Spraying Process

Abstract This paper presents a study of the residual stress and microstructural properties of thick, spray-formed components, produced using the High Velocity Oxy-Fuel (HVOF) thermal spraying process. The forming material used is Tungsten carbide cobalt (WC-Co), a material which is more usually processed using expensive press and sinter technology. The aim of this study is to examine the effect of production parameters on the formation of thick components. In order to fabricate thick specimens, certain problems have to be overcome. More specifically these problems include the minimizing residual stresses, which cause shape distortion in the components and maining the integrity of the coating on a microstructural scale. The dependence of residual stress, and sprayed material characteristics on spraying distance, and powder feed rate conditions is presented. Results show that cylindrical WC-Co components up to a thickness of 9mm can successfully be produced, by careful control of these parameters. This represents a significant improvement on maximum thickness values previously reported for WC-Co [1,2].

scholarly journals Hard Alloys with High Content of WC and TiC—Deposited by Arc Spraying Process

2020 ◽  
Author(s):  
Stefan Lucian Toma ◽  
Radu Armand Haraga ◽  
Daniela Lucia Chicet ◽  
Viorel Paleu ◽  
Costica Bejinariu
Keyword(s):  
High Hardness ◽  
Industrial Applications ◽  
Atmospheric Plasma ◽  
Arc Spraying ◽  
Hard Alloys ◽  
X Ray Diffraction ◽  
Additional Material ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Spraying Process

Obtained by different spraying technologies: in atmospheric plasma spray, High Velocity Oxygen Fuel (HVOF) or laser cladding, the layers of hard alloys with a high content of WC and TiC find their industrial applications due to their high hardness and resistance to wear. Recognized as being a process associated with welding, the arc spraying process is a method applied industrially both in obtaining new surfaces and for reconditioning worn ones. This chapter presents the technology for obtaining ultra-hard layers based on WC and TiC - by the arc spraying process, using a classic spray device equipped with a conical nozzle system and tubular wire additional material containing ultra-hard compounds (WC, TiC). To study both the quality of deposits and the influence of thermal spray process parameters on the properties of deposits with WC and TiC content, we approached various investigative techniques, such as optical scanning microscopy (SEM), X-ray diffraction, and determination of adhesion, porosity, Vickers micro-hardness and wear resistance.

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