Hydrogen Reduction of MoF6 and Molybdenum Carbide Formation in RF Inductively Coupled Low-Pressure Discharge: Experiment and Equilibrium Thermodynamics Consideration

RF inductor power losses of ferrite-free electrode-less low pressure mercury inductively-coupled discharges excited in closed-loop dielectric tube were studied. The modelling was made within the framework of low pressure inductive discharge transformer model for discharge lamps with tubes of 16, 25 and 38 mm inner diam. filled with the mixture of mercury vapour (7.5×10–3 mm Hg) and argon (0.1, 0.3 and 1.0 mm Hg) at RF frequencies of 1, 7; 3.4 and 5.1 MHz and plasma power of (25–500) W. Discharges were excited with the help of the induction coil of 3, 4 and 6 turns placed along the inner perimeter of the closed-loop tube. It was found that the dependence of coil power losses, Pcoil, on the discharge plasma power, Ppl, had the minimum while Pcoil decreased with RF frequency, tube diameter and coil number of turns. The modelling results were found in good qualitative agreement with the experimental data; quantitative discrepancies are believed to be due skin-effect and RF electric field radial inhomogeneity that were not included in discharge modelling.

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The Characteristics of a Ferrite-free Closed-loop Inductively-coupled Low-pressure Mercury Discharge Lamp

Vestnik MEI ◽

10.24160/1993-6982-2018-4-89-96 ◽

2018 ◽

Vol 4 (4) ◽

pp. 89-96 ◽

Cited By ~ 2

Author(s):

Oleg A. Popov ◽

◽

Pavel V. Starshinov ◽

Viktoriya N. Vasina ◽

◽

...

Keyword(s):

Closed Loop ◽

Low Pressure ◽

Inductively Coupled ◽

Discharge Lamp

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Specification for plastics hoses for suction and low-pressure discharge of petroleum liquids

10.3403/00418397 ◽

1987 ◽

Keyword(s):

Low Pressure ◽

Pressure Discharge

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Plastics hoses and hose assemblies for suction and low-pressure discharge of petroleum liquids. Specification

10.3403/30212875 ◽

2014 ◽

Keyword(s):

Low Pressure ◽

Pressure Discharge

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In-Situ Synchrotron X-ray Diffraction Investigation of Microstructural Evolutions During Low-Pressure Carburizing

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06171-2 ◽

2021 ◽

Author(s):

Ogün Baris Tapar ◽

Jérémy Epp ◽

Matthias Steinbacher ◽

Jens Gibmeier

Keyword(s):

Carbon Content ◽

Carbon Diffusion ◽

Low Pressure ◽

Carbon Accumulation ◽

Experimental Chamber ◽

Carbide Formation ◽

X Ray Diffraction ◽

X Ray ◽

Carbon Supply

AbstractAn experimental heat treatment chamber and control system were developed to perform in-situ X-ray diffraction experiments during low-pressure carburizing (LPC) processes. Results from the experimental chamber and industrial furnace were compared, and it was proven that the built system is reliable for LPC experiments. In-situ X-ray diffraction investigations during LPC treatment were conducted at the German Electron Synchrotron Facility in Hamburg Germany. During the boost steps, carbon accumulation and carbide formation was observed at the surface. These accumulation and carbide formation decelerated the further carbon diffusion from atmosphere to the sample. In the early minutes of the diffusion steps, it is observed that cementite content continue to increase although there is no presence of gas. This effect is attributed to the high carbon accumulation at the surface during boost steps which acts as a carbon supply. During quenching, martensite at higher temperature had a lower c/a ratio than later formed ones. This difference is credited to the early transformation of austenite regions having lower carbon content. Also, it was noticed that the final carbon content dissolved in martensite reduced compared to carbon in austenite before quenching. This reduction was attributed to the auto-tempering effect.

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