CC BY
29iSHS 2019
Moscow, Russia
REACTIVE PHASE FORMATION BY ELECTROSPARK DEPOSITION
M. I. Petrzhik*", A. E. Kudryashov", and E. I. Zamulaeva"
aNational University of Science and Technology MISiS, Moscow, 119049 Russia
*e-mail: petrzhik@shs.misis.ru
DOI: 10.24411/9999-0014A-2019-10124
The traditional task of ESD is to strengthen the surface layers of metal conductive substrates by transferring the refractory and high-strength phases contained in the precursor electrode. An example of such electrodes produced by SHS technology can be unique refractory carbides or laminate MAX phases [1]. With such solid-phase mass transfer, an important parameter of the process is the erosion ability of the electrode, and the formed coatings usually have an increased roughness.
On the contrary, the reactive phase formation takes place if the conditions for local melting are created during the electrospark deposition, in which the electrode and substrate components are actively mixed, culminating in the synthesis of new phases that were not in the system. This is possible with a strong chemical interaction of low-melting (near-eutectic) electrodes with the substrate components. Reasonably selected pairs of "glass-forming precursor-crystalline substrate" were successfully used to obtain coatings contained metallic mixed (metallic glass and nanocrystals) structure with superior properties [2, 3].
Due to the characteristic of eutectics ability to spread (fluidity) electrical discharge machining improves the quality and reduces the surface roughness. This was used to improve the surface quality of additive manufacturing products [4]. This was achieved with the help of ESD, as in the process of reactive electrospark deposition, three fast-flowing phenomena are observed: (1) plasma smoothing of protrusions, (2) filling in cavities and microcracks with a low-melting near-eutectic melt, which is formed during the rapid local melting of the precursor electrode under the conditions of a pulsed electric spark discharge, followed by (3) local reaction synthesis of wear-resistant intermetallic compounds during the chemical interaction of the melt with the substrate.
The reported study was partially funded by Russian Foundation for Basic Research (RFBR) and Bulgarian National Science Fund (BNSF) according to the research project no. 19-58-18022.
1. E.I. Zamulaeva, E.A. Levashov, T.A. Sviridova, N.V. Shvyndina, M.I. Petrzhik, Pulsed electrospark deposition of MAX phase Cr2AlC based coatings on titanium alloy, Surf. Coat. Technol, 2013, vol. 235, pp. 454-460.
2. M.I. Petrzhik, P.V. Vakaev, T.R. Chueva, T.A. Sviridova, V.V. Molokanov, Yu.K. Kovneristy, E.A. Levashov, From bulk metallic glasses to amorphous metallic coatings, J. Metastable Nanocryst. Mater., 2005, vol. 24-25, pp. 101-104.
3. M. Petrzhik, V. Molokanov, E. Levashov, On conditions of bulk and surface glass formation of metallic alloys, J. Alloys Compd., 2017, vol. 707, pp. 68-72.
4. S.K. Mukanov, M.I. Petrzhik, A.E. Kudryashov, E.A. Levashov, Elimination of surface defects of SLM products due to a synthesis of NiAl intermetallic at electro-spark deposition of Al-containing precursor, Presented at this Symposium.
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