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.

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.

The Ultimate Spray Booth

1997 ◽  
Author(s):  
L. Pejryd ◽  
J. Wigren ◽  
N. Hanner
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Design Element ◽  
Production Flow ◽  
Statistical Process ◽  
Spray Coatings ◽  
Spray Process ◽  
Spray Booth ◽  
On Line

Abstract Reproducibility is a current challenge for the thermal spray industry. Reproducibility associated problems represent a large cost every year not only in terms of rejections and rework, but also in costs for destructive testing and decreased production flow. Thermal spray coatings are moving in the direction of being considered only as a "band aid" to becoming a design element. One of the prerequisites for such a development is an increase in reproducibility for thermal spray coatings. The purpose of this paper is to outline a vision aiming in the direction of a future "ultimate spray booth", where thermal spraying is as reproducible and reliable as machining, grinding or other production processes. A way to increase reproducibility and reliability in the future spray shop involves utilising major parts of IT - technology. This also includes active co-operation design-production in the pre-spray process. This paper will deal with areas such as: operation drawings and lists through multimedia techniques, education programs for operators and designers through multimedia techniques, CAD/CAM, Off-line programming and simulation, On-line diagnostics of flame (particle diagnostics) and coating (temperature & Acoustic emission measurements), on-line Statistical Process Control and Knowledge Based System techniques.

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.

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.

Characterization of Microstructure and Properties of Plasma Sprayed Ceramic Coatings on AZ91 Magnesium Alloy

2011 ◽  
Vol 312-315 ◽  
pp. 571-576
Author(s):  
Grzegorz Moskal ◽  
Aleksander Iwaniak ◽  
Bartosz Witala
Keyword(s):  
Chemical Composition ◽  
Magnesium Alloy ◽  
Bond Coat ◽  
Thermal Spraying ◽  
Ceramic Coatings ◽  
Sem Analysis ◽  
Composition Analysis ◽  
Az91 Magnesium Alloy ◽  
Substrate Quality ◽  
Spraying Process

The paper presents the microstructure test results of carbide layers with bond coat obtained on the magnesium alloy with WC/Co – NiCr – AZ91D type thermal spraying method. Layers were sprayed with the APS method on the sandblasted surfaces of approx. 5 mm thick elements manufactured with high pressure die casting (HPDC). The standard process parameters were used for the powders sprayed. The scope of the tests included characteristics of the AZ91D alloy top surface after HPDC process and after sandblasting. The stereometric analysis of surface was performed by using the laser profilometer. The top surface geometric parameters were determined and presented in the form of numbers and topographic maps. Both surfaces were subject to SEM analysis by using the Hitachi S3400N microscope and chemical composition analysis in micro areas (EDX analysis by using the Noran System Six software) to determine presence of impurities and other type of artefacts on the alloy surface before plasma spraying. The alloy surfaces were also subject to detailed tests after spraying process (on lateral micro-sections) to determine the influence of the spraying process on the substrate quality and consequently layer adhesion. Phase composition assessment of the NiCr 80/20 type bond coat and carbide layers WC/10Co and WC/8Co was also performed. Further tests referred to top surface morphology of both carbide layers and chemical composition assessment in micro areas.

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].

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