Novel Method for In-Flight Particle Temperature and Velocity Measurements in Plasma Spraying Using a Single CCD Camera

Vattulainen, J.; Hämäläinen, Esa; Hernberg, Rolf; Vuoristo, Petri; Mäntylä, T.

doi:10.1361/105996301770349556

Cited by 58 publications

(21 citation statements)

References 9 publications

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“…Suspension plasma sraying was studied through: -The drop injection by imaging the plasma jet and the drop trajectory with the CCD camera of the SprayWatch system [30]. It uses a fast shutter camera and a filtered laser flash illumination at 808 nm allowing checking the good penetration of the suspension drops inside the plasma and choosing the optimal pressure of injection for a given liquid or suspension.…”

Section: Measurement Devicesmentioning

confidence: 99%

Phenomena Involved in Suspension Plasma Spraying Part 1: Suspension Injection and Behavior

Fazilleau

Delbos

Rat

et al. 2006

Plasma Chem Plasma Process

156

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Suspension Plasma Spraying (SPS) is a relatively new deposition process which enables to spray micron and submicron particles. It offers the possibility to form finely structured coatings with intermediate thicknesses of a few tens of microns. In order to have a better understanding in SPS, the two parts of this paper are devoted to the description of the phenomena involved in this spray process. The first part focuses on the suspension injection within a d.c. plasma jet. Simplified models, backed by plasma and suspension diagnostics, allow describing the interaction plasma-suspension. It is shown that the suspension is atomized by the plasma jet before the starting of the droplets vaporization. The plasma jet recovers its flow symmetry about 15 mm downstream of the nozzle exit. The strong influence of plasma instabilities on suspension injection is also highlighted. The second part is devoted to solid particle treatments and the coating formation.

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Section: Measurement Devicesmentioning

confidence: 99%

Phenomena Involved in Suspension Plasma Spraying Part 1: Suspension Injection and Behavior

Fazilleau

Delbos

Rat

et al. 2006

Plasma Chem Plasma Process

156

View full text Add to dashboard Cite

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“…Detailed discussion of these sensors is available in literature -e.g. DPV 2000, (1,2) LDA, (3) PSI (4,5) for the single particle based techniques and SPT & IPP, (6−8) Spray Watch, (9) Accuraspray, (10) ensemble apparatus similar to DPV, (11) PFI (12) for ensemble based techniques.…”

Section: Introductionmentioning

confidence: 99%

A Critical Assessment of Particle Temperature Distributions During Plasma Spraying: Experimental Results for YSZ

Streibl

Vaidya

Friis

et al. 2006

Plasma Chem Plasma Process

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Plasma sprayed coatings of Yttria Stabilized Zirconia (YSZ) have been studied extensively through the years to understand variations in coating properties as well as to achieve control on microstructure of the coatings. The requirement for microstructural control and reliability have become all the more important as coatings have now become part of an integrated "prime reliant" design strategy aimed at increasing turbine inlet temperature and associated efficiencies. One of the important thrusts in monitoring and controlling the process has been the application of process sensors that measure spray stream characteristics, notably particle temperature and velocity. Although single particle-based measurements have been available for some time, in general control strategies based on particle state rely on average values of temperature and velocity. In this study, a detailed examination of particle temperature distributions is presented. When systematically examined over a wide range of operating conditions of the resulting range of particle temperatures, a significant structure in the statistical distribution has been observed. A close inspection of the data indicates that this distribution can be interpreted as melting state indicator for YSZ. A characteristic peak at the melting point of ZrO 2 (error in absolute T -measurement is ≈ ±10%) can be used as an indicator for re-solidified particles. In the past, control strategies based on process diagnostic sensors have been based on average particle temperatures and velocities. Although the average values seem to be promising as control parameters, it has been shown through our results that different melting states could be demonstrated for the same average T and V settings. The melting state in turn has an important bearing on the coating structure and properties. It therefore implies that a process control strategy (to maintain coating quality) based on in flight particle sensors will have to take these findings into account. As an example, one strategy of process control would not only define the process in terms of the average particle temperature and velocity but also include the effect that parameter changes have on distributions.

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“…Distance of the camera from the spray gun was kept between 150 and 200 mm. Particle temperature determination is based on the two-color pyrometry and in-flight particle velocities are measured from the length of particle traces during known exposure times using a single high-speed CCD camera [25]. The average particle temperature is 2650 ± 50°C -which is below the melting point of YSZ [17] -and velocity prior to impact is 200 ± 50 m/sec.…”

Section: Online Particle Diagnosticsmentioning

confidence: 99%

Influence of in-flight particle state diagnostics on properties of plasma sprayed YSZ-CeO₂nanocomposite coatings

Mantry

Jha

Mandal

et al. 2014

International Journal of Smart and Nano Materials

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This article describes the influence of controlling in-flight hot particle characteristics on properties of plasma sprayed nanostructured yttria stabilized zirconia (YSZ) coatings. This article depicts dependence of adhesion strength of as-sprayed nanostructured YSZ coatings on particle temperature, velocity and size of the splat prior to impact on the metallic substrate. Particle temperature measurement is based on two-color pyrometry and particle velocities are measured from the length of the particle traces during known exposure times. The microstructure and adhesion strength of as-sprayed nano-YSZ coatings were studied. Field emission scanning electron microscopy results revealed that morphology of coating exhibits bimodal microstructure consisting of nano-zones reinforced in the matrix of fully melted particles. The coating adhesion strength is noticed to be greatly affected by the melting state of agglomerates. Maximum adhesion strength of 42.39 MPa has been experimentally found out by selecting optimum levels of particle temperature and velocity. The enhanced bond strength of nano-YSZ coating may be attributed to higher interfacial toughness due to cracks being interrupted by adherent nano-zones.

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Novel Method for In-Flight Particle Temperature and Velocity Measurements in Plasma Spraying Using a Single CCD Camera

Cited by 58 publications

References 9 publications

Phenomena Involved in Suspension Plasma Spraying Part 1: Suspension Injection and Behavior

Phenomena Involved in Suspension Plasma Spraying Part 1: Suspension Injection and Behavior

A Critical Assessment of Particle Temperature Distributions During Plasma Spraying: Experimental Results for YSZ

Influence of in-flight particle state diagnostics on properties of plasma sprayed YSZ-CeO₂nanocomposite coatings

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Novel Method for In-Flight Particle Temperature and Velocity Measurements in Plasma Spraying Using a Single CCD Camera

Cited by 58 publications

References 9 publications

Phenomena Involved in Suspension Plasma Spraying Part 1: Suspension Injection and Behavior

Phenomena Involved in Suspension Plasma Spraying Part 1: Suspension Injection and Behavior

A Critical Assessment of Particle Temperature Distributions During Plasma Spraying: Experimental Results for YSZ

Influence of in-flight particle state diagnostics on properties of plasma sprayed YSZ-CeO2nanocomposite coatings

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Influence of in-flight particle state diagnostics on properties of plasma sprayed YSZ-CeO₂nanocomposite coatings