Wave mode high voltage consolidation of powder materials

Grigoryev, E. G.; Olevsky, Eugene A.; Yudin, A. V.; Yurlova, M. S.

doi:10.1016/j.commatsci.2014.10.067

Cited by 7 publications

(12 citation statements)

References 10 publications

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“…This effect could be caused by non-uniform consolidation of the powder. During electric discharge the powder areas located closer to the punches can densify more intensively due to higher values of plastic deformation in comparison with the central part [ 20 ]. Another reason for this effect may be associated with high heating and cooling rates of these areas.…”

Section: Resultsmentioning

confidence: 99%

Microstructure Investigation of 13Cr-2Mo ODS Steel Components Obtained by High Voltage Electric Discharge Compaction Technique

Bogachev¹,

Yudin²,

Grigoryev³

et al. 2015

Materials

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Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10–15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining the initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. The choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality.

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Section: Resultsmentioning

confidence: 99%

Microstructure Investigation of 13Cr-2Mo ODS Steel Components Obtained by High Voltage Electric Discharge Compaction Technique

Bogachev¹,

Yudin²,

Grigoryev³

et al. 2015

Materials

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“…As mathematically and experimentally studied, there is also an upper critical value of the current amplitude, which depends on the external mechanical pressure, beyond which the interparticle contacts in powder particles disintegrate via an electrothermal explosion. This makes disintegrating the column centre like an exploding wire, even making the consolidated material be thrown out from the die [27][28][29]. The combined control of the applied pressure and current amplitude is therefore mandatory in this technique.…”

Section: General Overviewmentioning

confidence: 99%

“…Moreover, pressure is critical under certain processing conditions; low pressures could just create local conductive channels or paths in the powder column, which absorb the whole energy creating inhomogeneous structures. On the other hand, high pressures could make interparticle contacts to reach a low temperature, insufficient to destroy the particle surface oxide films, affecting the consolidation of the sample [27,28]. Pressure is therefore a key parameter to be tested and controlled to attain the desired results.…”

Section: General Overviewmentioning

confidence: 99%

“…More complex models, allowing the prediction of several parameters in the process, have been developed. In particular, regarding temperature, more elaborated models can be found in [28,49,50]. The simulation of the EDC coupled process, including the electric, thermal, mechanical, and microstructural problems, has been carried out using the finite elements method (FEM) implemented in Comsol Multiphysics.…”

Section: General Overviewmentioning

confidence: 99%

“…For instance, discharge times of 86, 124 and 153 μs were estimated for Ti powders and capacitances of 150, 300 and 450 μF [37]. In addition, the cooling time of the consolidated material depends on processing parameters, as well as on the thermal conductivity of the materials and the size of the compacted sample, being in the order of 2.5 s [27,28]. Some other effects, such as recrystallization, have also been considered to explain the EDC process.…”

Section: Stages Of the Edc Processmentioning

confidence: 99%

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Capacitor Electrical Discharge Consolidation of Metallic Powders—A Review

Aranda

Fernández

Lozano-Pérez

et al. 2021

Metals

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Manufacturing metallic materials from elemental or alloyed powders is an option in many industrial processes. Nevertheless, the traditional powder metallurgy processing including furnace sintering is at times detrimental for the microstructure attained in the powders. Alternative sintering processes based on the use of electricity and the energy obtained by the Joule effect in powder particles can be quick enough to avoid microstructural changes. In particular, when the energy is stored in a capacitor and then discharged, the heating process is extremely quick, lasting milliseconds or even microseconds. This process, generally known as electrical discharge consolidation, has been applied to a wide variety of metallic materials, easily preserving the original microstructure of the powders. Both porous or homogeneous and highly densified material can be obtained, and without losing the desired properties of the consolidated material. A general overview of the process and applications, as well as the results obtained by different research groups around the world, have been reviewed in this manuscript.

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