Arc voltage fluctuations: Comparison between two plasma torch types

Noguès, E.; Vardelle, Michel; Fauchais, Pierre; Granger, Pierre‐Yves

doi:10.1016/j.surfcoat.2008.04.014

Cited by 41 publications

(21 citation statements)

References 3 publications

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“…Effect of jet instabilities on results of plasma processing technologies has primary importance. Effect of arc fluctuations on properties of plasma sprayed coatings was studied in [15,16]. Different types of arc fluctuations were detected and characterized during the process of nanosynthesis in [17], where it has been shown that size of nanoparticles is strongly related to the characteristics of arc voltage fluctuations.…”

Section: Introductionmentioning

confidence: 99%

Resonant Excitation of Boundary Layer Instability of DC Arc Plasma Jet by Current Modulation

Kopecký

Hrabovský

2011

Plasma Chem Plasma Process

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Instabilities of thermal plasma jets were studied on the basis of analysis of plasma radiation fluctuations recorded by an array of high frequency photodiodes. Characteristic frequencies of jet oscillations were found and spatial distribution of amplitude of plasma fluctuations was determined. The influence of arc current ripple on plasma instabilities was investigated for two types of power supply-classical thyristor controlled unit with the frequency of the current ripple 300 Hz and the rectifier with the high frequency converter and frequency of the current modulation 30 kHz. Generation of boundary layer instability with the current modulation frequency and its harmonics was proved using fast Fourier transform, contour plots and phase portraits. It was found that the character of fluctuations of plasma jet was substantially influenced by current ripple with the frequency or its harmonics close to the frequency of oscillations generated by boundary layer instability.

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Section: Introductionmentioning

confidence: 99%

Resonant Excitation of Boundary Layer Instability of DC Arc Plasma Jet by Current Modulation

Kopecký

Hrabovský

2011

Plasma Chem Plasma Process

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“…Although a large number of experimental and modeling results concerning the plasma spraying process have been published [5][6][7], the complicated interactions of the plasma with electromagnetic, thermal, and acoustics phenomena are still not fully understood [8]. In plasma spraying, the anode nozzle is one of the key components of the plasma torch.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Anode Inner Contour on Atmospheric DC Plasma Spraying Process

Wen¹,

Liu²,

Zhou³

et al. 2017

Advances in Materials Science and Engineering

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In thermal plasma spraying process, anode nozzle is one of the most important components of plasma torch. Its inner contour controls the characteristics of plasma arc/jet, determining the motion and heating behaviors of the in-flight particles and hence influencing the coating quality. In this study, the effects of anode inner contour, standard cylindrical nozzle, and cone-shaped Laval nozzle with conical shape diverging exit (CSL nozzle) on the arc voltage, net power, thermal efficiency, plasma jet characteristics, in-flight particle behaviors, and coating properties have been systematically investigated under atmospheric plasma spraying conditions. The results show that the cylindrical nozzle has a higher arc voltage, net power, and thermal efficiency, as well as the higher plasma temperature and velocity at the torch exit, while the CSL nozzle has a higher measured temperature of plasma jet. The variation trends of the plasma jet characteristics for the two nozzles are comparable under various spraying parameters. The in-flight particle with smaller velocity of CSL nozzle has a higher measured temperature and melting fraction. As a result, the coating density and adhesive strength of CSL nozzle are lower than those of cylindrical nozzle, but the deposition efficiency is greatly improved.

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“…The SPS process typically uses moderate uniaxial pressures below 100 MPa and commonly in vacuum. As indicated from the plasma spraying technique, gases like H 2 , Ar, O 2 , and so on can be used as plasma generating gases which can enhance the plasmas generation 11, 12. In this study, the diamond synthesis from CNTs through the generation of plasmas during the SPS was investigated by very low pressure and various atmosphere SPS experiments.…”

Section: Introductionmentioning

confidence: 99%

Diamond synthesis through the generation of plasma during spark plasma sintering

Zhang

Ahmed

Bednarčı́k³

et al. 2012

Physica Status Solidi (a)

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Spark plasma sintering (SPS) of carbon nanotubes based materials to diamond was conducted at a very low pressure in vacuum and argon atmospheres. The phases and microstructures of the sintered samples were analyzed by Synchrotron X‐ray, Raman spectroscopy, and scanning electron microscopy. Diamond phases are created from carbon nanotubes/FeNi mixtures at pressure of 9.55 MPa in vacuum and argon atmospheres during SPS. At this pressure, carbon flowers, and perfect diamond crystals are obtained at 1200 °C only in the argon atmosphere. The consequences provide an indirect evidence for the existence of plasma during SPS. The argon atmosphere promotes the plasma generation and thus enhances the diamond transition. Diamonds are obtained from carbon nanotubes/FeNi at 1200 °C and 9.55 MPa in argon atmosphere of SPS.

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Arc voltage fluctuations: Comparison between two plasma torch types

Cited by 41 publications

References 3 publications

Resonant Excitation of Boundary Layer Instability of DC Arc Plasma Jet by Current Modulation

Resonant Excitation of Boundary Layer Instability of DC Arc Plasma Jet by Current Modulation

The Influence of Anode Inner Contour on Atmospheric DC Plasma Spraying Process

Diamond synthesis through the generation of plasma during spark plasma sintering

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