Effect of pulsed DC current on atomic diffusion of Nb–C diffusion couple

Kondo, Takayuki; Yasuhara, Masahide; Kuramoto, Taku; Kodera, Yasuhiro; Ohyanagi, Manshi; Munir, Zuhair A.

doi:10.1007/s10853-008-2758-z

Cited by 46 publications

(14 citation statements)

References 22 publications

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“…The effect of current on reactivity in the PECS has been investigated 56,87–89 . The reaction between Mo foils and Si wafers was investigated under PECS conditions with and without a current passing through the multilayer ensemble 56 .…”

Section: Pecs Parameters and Their Effect On Processingmentioning

confidence: 99%

Electric Current Activation of Sintering: A Review of the Pulsed Electric Current Sintering Process

Munir

Quach

Ohyanagi

2010

Journal of the American Ceramic Society

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567

229

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The phenomenal increase during the past decade in research utilizing pulsed electric current to activate sintering is attributed generally to the intrinsic advantages of the method relative to conventional sintering methods and to the observations of the enhanced properties of materials consolidated by this method. This review focuses on the fundamental aspects of the process, discussing the reported observations and simulation studies in terms of the basic aspects of the process and identifying the intrinsic benefits of the use of the parameters of current (and pulsing), pressure, and heating rate. Feature D. J. Green-contributing editor

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Section: Pecs Parameters and Their Effect On Processingmentioning

confidence: 99%

Electric Current Activation of Sintering: A Review of the Pulsed Electric Current Sintering Process

Munir

Quach

Ohyanagi

2010

Journal of the American Ceramic Society

Self Cite

567

229

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“…The analysis of the few previously reported experimental results on this matter is not conclusive. In fact, an intrinsic effect of the application of a pulsed electric current have been experimentally observed only on the solid-state diffusion during steel plates boriding [21] and on reactivity during diffusion couples experiments [22][23][24]. On the other hand, by imposing the same temperature and mechanical pressure, similar densities and microstructures were observed in electrically conductive ceramic samples heated by either restricting the current to flow only through the powder or with current allowed to pass through both the graphite die and the powder [20].…”

Section: Resultsmentioning

confidence: 99%

A methodology to investigate the intrinsic effect of the pulsed electric current during the spark plasma sintering of electrically conductive powders

Locci

Cincotti

Todde

et al. 2010

Science and Technology of Advanced Materials

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Cao (2010) A methodology to investigate the intrinsic effect of the pulsed electric current during the spark plasma sintering of electrically conductive powders, Science Abstract A novel methodology is proposed for investigating the effect of the pulsed electric current during the spark plasma sintering (SPS) of electrically conductive powders without potential misinterpretation of experimental results. First, ensemble configurations (geometry, size and material of the powder sample, die, plunger and spacers) are identified where the electric current is forced to flow only through either the sample or the die, so that the sample is heated either through the Joule effect or by thermal conduction, respectively. These ensemble configurations are selected using a recently proposed mathematical model of an SPS apparatus, which, once suitably modified, makes it possible to carry out detailed electrical and thermal analysis. Next, SPS experiments are conducted using the ensemble configurations theoretically identified. Using aluminum powders as a case study, we find that the temporal profiles of sample shrinkage, which indicate densification behavior, as well as the final density of the sample are clearly different when the electric current flows only through the sample or through the die containing it, whereas the temperature cycle and mechanical load are the same in both cases.Keywords:electriccurrent,Jouleeffect,modeling,sparkplasmasintering

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“…It was reported that vacancy concentrations and their mobility in some metallic materials had been increased by a direct current flowing through them. 18,19 Similarly, higher current at the surface induced by the ACF would lead to highest vacancy concentration in the surface region. Therefore, the inward diffusion of boron is intensified, and the high concentration of boron in the surface layer at the beginning of the boriding is decreased with prolonged soaking time.…”

Section: Discussionmentioning

confidence: 99%

Study on effects of alternating current field to pack boriding of medium carbon steel

Xie

Cheng

2014

International Heat Treatment and Surface Engineering

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A plain medium carbon steel was borided by alternating current field enhanced pack boriding (ACFEPB). Diffusion kinetics and case characteristics of the borided steel were investigated to understand effects of an alternating current field (ACF) on pack boriding. Conventional pack boriding (CPB) was also employed for comparison. A series of boriding were conducted at temperatures of 873, 973, 1073 and 1173 K for 1, 2, 4 and 6 h, respectively, with a fixed current of 4 A. The morphology and types of borides formed in the steel were investigated by optical microscopy and X-ray diffraction, respectively. Boride growth kinetics was analysed by measuring the average thickness of the boriding case as a function of time and temperature. The growth rate of the ACFEPB case versus time showed the same parabolic character as CPB. The parameters of the boron diffusion kinetics, D5D 0 exp(2QR 21 T 21 ), have been determined. The results showed that the ACF enhanced inter-diffusion of boron in the substrate. The value of D, diffusion coefficient, in ACFEPB was more than 4 times of that in the CPB. The activation energy Q (44?45 kJ mol 21 ) of the borided steel in the ACFEPB was less than 1/4 of that (180?6 kJ mol 21 ) in the CPB.

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Effect of pulsed DC current on atomic diffusion of Nb–C diffusion couple

Cited by 46 publications

References 22 publications

Electric Current Activation of Sintering: A Review of the Pulsed Electric Current Sintering Process

Electric Current Activation of Sintering: A Review of the Pulsed Electric Current Sintering Process

A methodology to investigate the intrinsic effect of the pulsed electric current during the spark plasma sintering of electrically conductive powders

Study on effects of alternating current field to pack boriding of medium carbon steel

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