HARDENING OF STEEL COMPONENTS BY MICROARC OXIDATION USING AN ALUMINUM SUBLAYER OBTAINED BY COLD GAS-DYNAMIC SPRAYING

KOMAROV Alexander I., Ph. D. in Eng., Head of the Laboratory of Modification Technologies of Engineering Materials, Joint Institute of Mechanical Engineering of the NAS of Belarus, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

GORANSKIY Georgiy G., Ph. D. in Eng., Leading Researcher of the Department of Multi-Functional Coatings, Science and Technology Park of BNTU “Polytechnic”, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

The efficiency of creating oxide-ceramic coatings on the surface of steel products is demonstrated by the combination of preliminary cold gas-dynamic spraying of an aluminum sublayer and its subsequent microarc oxidation. The resulting gas-dynamic coatings are a composite material consisting of an aluminum matrix and inclusions of corundum particles (~15  %), assimilated from the powder sprayed. Homogeneous with a low (1–6  %) porosity base structure and evenly distributed corundum particles provide a high level of adhesion (up to 122 MPa), hardness (up  to 1140 MPa) and viscosity (up to 46  %) of coating. The ceramic coatings formed on an aluminum sublayer with a thickness of up to 180 μm are characterized by a homogeneous structure of the base layer. The phase composition of the surface layers of coatings is represented by γ-Al₂O₃, high-strength α-Al₂O₃ oxides and mullite, the content of which is 45  %, 40  %, 15  %, respectively. With the deepening into the coating, a significant (up to 80  %) increase in the content of Al₂O₃ is noted with a simultaneous decrease in the volume fraction of γ-Al₂O₃ and the absence of mullite. A consequence of this is a sufficiently high (up to 19 GPa) level of maximum hardness values in these coating layers, a reduction in the coefficient of friction to a value of 0.048 at the stage of steady wear with limited oil supply, and no wear of the ceramic coating under these test conditions.

cold gas-dynamic spraying, microarc oxidation, ceramic coating, adhesion, microhardness, corundum

• Vityaz P.A., Zhornik V.I., Ilyushchenko A.F., Senyut V.T., Komarov A.I. Nanoalmazy detonatsionnogo sinteza: poluchenie i primenenie [Nanodiamonds of detonation synthesis: preparation and application]. Minsk, Belaruskaya navuka Publ., 2013. 380 p.
• Vityaz P.A., Komarov A.I., Komarova V.I. Sozdanie iznosostoykikh uprochnyayushchikh pokrytiy mikrodugovym oksidirovaniem neposredstvennoy i posleduyushchey modifikatsiey uglerodnymi nanomaterialami [Creation of wear-resistant hardening coatings by microarc oxidation by direct and subsequent modification with carbon nanomaterials]. Perspektivnye tekhnologii [Advanced technologies], 2011, ch. 6, pp. 114–148.
• Vityaz P.A. Komarov A.I., Komarova V.I., Kuznetsova  T.A. Osobennosti formirovaniya iznosostoykikh sloev na poverkhnosti modifitsirovannogo fullerenami MDO-pokrytiya pri trenii [Features of the formation of wear-resistant layers on the surface of a modified by fullerenes of MDO coatings during friction]. Trenie i iznos [Friction and wear], 2011, vol. 32, no. 4, pp. 313–325.
• Kulakov K.V. Tekhnologiya vosstanovleniya detaley iz alyuminievykh splavov gazodinamicheskim napyleniem s uprochneniem mikrodugovym oksidirovaniem. Diss. kand. tekhn. nauk [Technology of restoration of details from aluminum alloys by gas-dynamic spraying with strengthening by microarc oxidation. Ph.D. Thesis]. Orel, 2006. 142 p.
• Ryabov V.R. Primenenie bimetallicheskikh i armirovannykh stalealyuminievykh soedineniy [Application of bimetallic and reinforced steel-aluminum compounds]. Moscow, Mashinostroenie Publ., 1975. 288 p.
• Vityaz P.A, Ivashko V.C., Ilyushchenko A.F., Shevtsov A.I., Manoylo E.D. Teoriya i praktika naneseniya pokrytiy [Theory and practice of coatings]. Minsk, Belaruskaya navuka Publ., 1998. 583 p.
• Kosarev V.F. Fizicheskie osnovy holodnogo gazodinamicheskogo napyleniya. Diss. dokt. fiz-mat. nauk [Physical basis of cold gas-dynamic spraying. D.Sc. Thesis]. Novosibirsk, 2003. 292 p.
• Tushinskiy L.I., Alkhimov A.P., Kosarev V.F., Plokhov A.V., Mochalina N.S. Struktura i svoystva alyuminievykh pokrytiy, nanesennykh metodom holodnogo gazodinamicheskogo napyleniya [Structure and properties of aluminum coatings deposited by the method of cold gas-dynamic spraying]. Teplofizika i aeromekhanika [Thermophysics and Aeromechanics], 2006, vol. 13, no. 1, pp. 141–145.
• Komarov A.I. Osobennosti formirovaniya pokrytiy na alyuminievykh splavakh s geterogennoy strukturoy metodom mikrodugovogo oksidirovaniya [Features of the formation of coatings on aluminum alloys with a heterogeneous structure by the method of microarc oxidation]. Materialy, tekhnologii, instrumenty [Materials, technologies, tools], 2003, vol. 8, no. 1, pp. 97–101.
• Komarov A.I. Obemno modifitsirovannoe karbidom titana oksidnoe keramicheskoe pokrytie na evtekticheskom silumine: poluchenie, strukturno-fazovoe sostoyanie, svoystva [Oxide ceramic coating volume-modified with titanium carbide on eutectic silumine: production, structural-phase state, properties]. Mekhanika mashin, mekhanizmov i materialov [Mechanics of machines, mechanisms and materials], 2016, no. 1(34), pp. 68–74.