Plasma Spray-PVD: Plasma Characteristics and Impact on Coating Properties

Mauer, Georg; Vaßen, Robert

doi:10.1088/1742-6596/406/1/012005

Cited by 39 publications

(17 citation statements)

References 31 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Based on the measured emission spectra, the excitation temperatures in the plasma can be determined by the Boltzmann plot method [14]. However, as the plasma jet is optically thin, the lateral setup of OES allows collecting only the integral intensities of the spectral lines along the line of measurement.…”

Section: Experimental Methods and Evaluation Principlesmentioning

confidence: 99%

“…Plasma radiation was collected through a borosilicate glass window and an achromatic lens, transferred by an optical fiber to the 50 µm entrance slit of the spectrometer and detected by a 1024x1024 pixels CCD array. The system is equipped with an Echelle grating, and the spectral resolution obtained is 15.9-31.8 pm [14]. The scanning wavelength range is 381-786 nm, which was calibrated by a standard Hg lamp.…”

Section: Methodsmentioning

confidence: 99%

“…Seven He I lines were chosen as in ref. [14] to calculate the excitation temperature. As shown in Fig.…”

Section: Intensity and Emissivity Profilesmentioning

confidence: 99%

“…The composition of the plasma gas has a significant influence on the microstructures of the PS-PVD coatings [11][12][13][14][15]. A standard plasma gas mixture of argon and helium is normally used to manufacture columnar structured ceramic coatings which have shown excellent performance in cyclic lifetime tests [16].…”

Section: Introductionmentioning

confidence: 99%

“…A standard plasma gas mixture of argon and helium is normally used to manufacture columnar structured ceramic coatings which have shown excellent performance in cyclic lifetime tests [16]. In earlier studies, the typical plasma characteristics of the PS-PVD process and the impact on the coating properties were investigated by OES [14,17].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Excitation Temperature and Constituent Concentration Profiles of the Plasma Jet Under Plasma Spray-PVD Conditions

Mauer

Vaßen

2017

Plasma Chem Plasma Process

View full text Add to dashboard Cite

Plasma spray-physical vapor deposition (PS-PVD) is a promising technology to produce columnar structured thermal barrier coatings with excellent cyclic lifetime. The characteristics of plasma jets generated by standard plasma gases in the PS-PVD process, argon and helium, have been studied by optical emission spectroscopy. Abel inversion was introduced to reconstruct the spatial characteristics. In the central area of the plasma jet, the ionization of argon was found to be one of the reasons for low emission of atomic argon. Another reason could be the demixing so that helium prevails around the central axis of the plasma jet. The excitation temperature of argon was calculated by the Boltzmann plot method. Its values decreased from the center to the edge of the plasma jet. Applying the same method, a spurious high excitation temperature of helium was obtained, which could be caused by the strong deviation from local thermal equilibrium of helium. The addition of hydrogen into plasma gases leads to a lower excitation temperature, however a higher substrate temperature due to the high thermal conductivity induced by the dissociation of hydrogen. A loading effect is exerted by the feedstock powder on the plasma jet, which was found to reduce the average excitation temperature considerably by more than 700 K in the Ar/He jet.

show abstract

Section: Experimental Methods and Evaluation Principlesmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Seven He I lines were chosen as in ref. [14] to calculate the excitation temperature. As shown in Fig.…”

Section: Intensity and Emissivity Profilesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Excitation Temperature and Constituent Concentration Profiles of the Plasma Jet Under Plasma Spray-PVD Conditions

Mauer

Vaßen

2017

Plasma Chem Plasma Process

View full text Add to dashboard Cite

show abstract

Application of Calibration-Free Boltzmann Plot Method for Composition and Pressure Measurement in Argon Free-Burning Arcs

Zhang

Sun

et al. 2019

Plasma Chem Plasma Process

View full text Add to dashboard Cite

How Hydrogen Admixture Changes Plasma Jet Characteristics in Spray Processes at Low Pressure

Mauer

2020

Plasma Chem Plasma Process

View full text Add to dashboard Cite

In plasma spraying, hydrogen is widely used as a secondary working gas besides argon. In particular under low pressure, there are strong effects on the plasma jet characteristics even by small hydrogen percentages. Under such conditions, fundamental mechanisms like diffusion and recombination are affected while this is less relevant under atmospheric conditions. This was investigated for argon–hydrogen mixtures by optical emission spectroscopy (OES). The small electron densities under the investigated low pressure conditions implied specific difficulties in the application of several OES-based methods which are discussed in detail. Adding hydrogen to the plasma gas effected an increased plasma enthalpy. Moreover, the jet expanded radially as the reactive part of the thermal conductivity was enhanced by recombination of atomic hydrogen so that the shock waves were less reflected at the cold jet rims. In the jet cores, the lowest temperatures were found for the highest hydrogen admixture because the energy consumption due to the dissociation of molecular hydrogen outbalanced the increase of the plasma enthalpy. Variations in the radial temperature profiles were related to the jet structure and radial thermal conductivity. The local hydrogen–argon concentration ratios revealed an accumulation of hydrogen atoms at the jet rims. Clear indications were found, that higher hydrogen contents promoted the fast recombination of electrons and ions. However, it is assumed that the transport properties of the plasma were hardly affected by this, since the electron densities and thus the ionization degrees were generally small due to the low pressure conditions.

show abstract

Plasma Spray-PVD: Plasma Characteristics and Impact on Coating Properties

Cited by 39 publications

References 31 publications

Excitation Temperature and Constituent Concentration Profiles of the Plasma Jet Under Plasma Spray-PVD Conditions

Excitation Temperature and Constituent Concentration Profiles of the Plasma Jet Under Plasma Spray-PVD Conditions

Application of Calibration-Free Boltzmann Plot Method for Composition and Pressure Measurement in Argon Free-Burning Arcs

How Hydrogen Admixture Changes Plasma Jet Characteristics in Spray Processes at Low Pressure

Contact Info

Product

Resources

About