Mathematical simulation of the layer growth kinetics during post-discharge nitriding: From early stage to quasi-steady stage

Castillo, Francisco; Oseguera, J.; Gómez, Adriana Gómez; Fraguela, A.

doi:10.1016/j.surfcoat.2008.08.016

Cited by 6 publications

(6 citation statements)

References 17 publications

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“…The following mathematical model, which describes the layer formation and the layer growth kinetics through a moving boundary problem, was presented in [13] and has been used in [12]. In building the mathematical model for the layer growth, the following assumptions are made: -Once the threshold concentration value on the surface is reached, the layer formation of phases in plane fronts parallel to the surface begins.…”

Section: Mathematical Modelmentioning

confidence: 99%

Post-Discharge Nitriding: Mathematical Modeling and Numerical Simulation of the Layer Growth

Castillo

Oseguera

Fraguela

et al. 2009

DDF

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Nitriding by microwave post-discharge process involves molecular nitrogen dissociation. It has been observed that nitrogen flux from surface to solid during the early stage does not follow a parabolic regime and that the growth rate of concomitant nitride layers is sensitive to atomic nitrogen concentration on the surface. In this work a mathematical model has been developed in order to describe the kinetics of the compound layer formation during a post-discharge nitriding process. The model is related to a moving boundary value problem and considers different stages: diffusion process, formation of the layers, layer growth and quasi-stabilization of the layer growth. Natural conditions on the nitrogen concentration consistent with the mass transfer mechanism are assumed. An analytical approximate solution of Goodman’s type is sought and numerical simulation is conducted to study the nitride layer growth.

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Section: Mathematical Modelmentioning

confidence: 99%

Post-Discharge Nitriding: Mathematical Modeling and Numerical Simulation of the Layer Growth

Castillo

Oseguera

Fraguela

et al. 2009

DDF

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“…In this study, a new kinetic approach based on the integral method was successfully applied to the boriding kinetics of AISI D2 steel. The similar approach was already applied by Leon Cazares et al [32,33] to simulate the growth kinetics of plasma nitrided pure iron. Based on this integral method, an original model was then suggested to model the growth kinetics of the bilayer (FeB + Fe 2 B) as a function of boriding parameters, taking into account certain assumptions.…”

Section: Introductionmentioning

confidence: 99%

“…It is possible to obtain the expressions of boronconcentration profiles through the FeB and Fe 2 B layers using the Goodman's method, also called the heat balance integral method (HBIM) [32,33]. According to it, we have (11) (12) The time-dependent unknown parameters a 1 (t), b 1 (t), a 2 (t), b 2 (t), u(t), and v(t) must satisfy the boundary conditions given by Equations (2)- (5).…”

mentioning

confidence: 99%

Simulation of the Growth Kinetics of FeB and Fe2B Layers on AISI D2 Steel by the Integral Method

Кеддам¹,

Kulka

2018

Phys. Metals Metallogr.

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In the present study, a new diffusion model based on the integral method was suggested to investigate the boriding kinetics of pack-borided AISI D2 steel. This diffusion model considered the effect of boride incubation time of the total boride layer (FeB + Fe 2 B). Firstly, the diffusion coefficients of boron in the FeB and Fe 2 B layers were estimated using a simple approach derived from the integral method. Secondly, the values of boron activation energies for the FeB and Fe 2 B layers were determined and compared with the literature data. The formulated diffusion model has been validated by using additional boriding conditions. The total boride layer thicknesses, obtained experimentally at 1243 K for 2, 4 and 6 h, were compared to the predicted thicknesses. Finally, a good agreement was observed between the experimental and the predicted results.

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“…The discharge dissociation and excitation of precursor molecules conducted by means of emission spectrum of pulsed direct current (DC) discharge is used to produce gas-phase free radicals and ions. It is a commonly used method requiring simple equipments compared with photolysis, pyrolysis, electron collision and other discharge methods [1][2][3][4][5]. The method has already been widely used to investigate near-infrared, far-infrared, microwave spectra and other optical spectra of free radicals and positive ions in flow systems [6,7].…”

Section: Introductionmentioning

confidence: 99%

Development and application of network virtual instrument for emission spectrum of pulsed high-voltage direct current discharge

Gong

2017

J. Inst.

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Network virtual instrument (VI) is a new development direction in current automated test. Based on LabVIEW, the software and hardware system of VI used for emission spectrum of pulsed high-voltage direct current (DC) discharge is developed and applied to investigate pulsed high-voltage DC discharge of nitrogen. By doing so, various functions are realized including real time collection of emission spectrum of nitrogen, monitoring operation state of instruments and real time analysis and processing of data. By using shared variables and DataSocket technology in LabVIEW, the network VI system based on field VI is established. The system can acquire the emission spectrum of nitrogen in the test site, monitor operation states of field instruments, realize real time face-to-face interchange of two sites, and analyze data in the far-end from the network terminal. By employing the network VI system, the staff in the two sites acquired the same emission spectrum of nitrogen and conducted the real time communication. By comparing with the previous results, it can be seen that the experimental data obtained by using the system are highly precise. This implies that the system shows reliable network stability and safety and satisfies the requirements for studying the emission spectrum of pulsed high-voltage discharge in high-precision fields or network terminals. The proposed architecture system is described and the target group gets the useful enlightenment in many fields including engineering remote users, specifically in controland automation-related tasks. K: Control systems; Hardware and accelerator control systems; Software architectures (event data models, frameworks and databases); Ion identification systems 1Corresponding author.

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Mathematical simulation of the layer growth kinetics during post-discharge nitriding: From early stage to quasi-steady stage

Cited by 6 publications

References 17 publications

Post-Discharge Nitriding: Mathematical Modeling and Numerical Simulation of the Layer Growth

Post-Discharge Nitriding: Mathematical Modeling and Numerical Simulation of the Layer Growth

Simulation of the Growth Kinetics of FeB and Fe2B Layers on AISI D2 Steel by the Integral Method

Development and application of network virtual instrument for emission spectrum of pulsed high-voltage direct current discharge

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