Siberian State Industrial University (Novokuznetsk, Russia)

S. V. Konovalov, Dr. Eng., Vice-Rector for Research and Innovation, Head of the Department of Mechanics and Engineering, konovalov@sibsiu.ru
V. K. Drobyshev, Researcher, Laboratory of Electron Microscopy and Image Processing, Postgraduate Student, Dept. of Metal Forming and Materials Science, EVRAZ ZSMK, drobyshev_v.k@mail.ru
I. A. Panchenko, Cand. Eng., Head of Laboratory of Electron Microscopy and Image Processing, panchenko_ia@sibsiu.ru
E. M. Zapolskaya, Cand. Eng., Senior Researcher, Laboratory of Electron Microscopy and Image Processing, vestnicsibgiu@sibsiu.ru
A. R. Mikhno, Director of the Scientific and Production Center “Welding Processes and Technologies”, welding@sibsiu.ru
V. M. Alzhev, Laboratory Assistant, Electron Microscopy and Image Processing Laboratory, alzhev_vm@sibsiu.ru

This paper presents a comparative study of two manufacturing methods for Co–Cr–Fe–Mn–Ni high-entropy alloys: vacuum induction casting and wire-arc cladding. The microstructure of the as-cast alloy specimens is entirely face-centered cubic (FCC), exhibiting dendritic segregation with the enrichment of interdendritic regions with nickel and manganese. The maximum microhardness reaches 155 HV at a content of 30 at.% Mn and 10 at.% Fe; however, the wear rate under these conditions is 8.81×10^-5 mm³/(N·m). Compositional optimization to Co₂₀Cr₂₀Fe₃₀Mn₁₀Ni₂₀ allows for reducing the wear rate to 2.09×10^-5 mm³/(N·m), which is 4.2 times less than that of the manganese-enriched counterpart. The microstructure of the alloy produced by wire-arc cladding is characterized by a pronounced structural heterogeneity resulting from rapid crystallization and the diffusion of iron from the substrate. Despite a microhardness variation ranging from 151 to 181 HV, the clad specimens exhibit an ultimate tensile strength of 943 MPa and an elongation of 36.8%, which surpass the performance of their as-cast counterparts. Conversely, in the as-cast state, the microstructure forms under slower cooling conditions, which promotes dendritic segregation and a relatively coarse dispersion of structural constituents, thereby limiting ductility and wear resistance. The obtained results demonstrate that wire-arc cladding is a promising method for the localized formation of wear-resistant functional layers with high strength and toughness, whereas the casting method is suitable for producing bulk blanks with predictable but lower wear resistance. The following optimization strategies are proposed: adjusting the manganese-to-iron ratio and applying heat treatment for the as-cast alloys, and controlling the heat input and core powder composition for the wire-arc coatings to minimize iron dilution.
The study was conducted under the State Assignment of the Ministry of Science and Higher Education of the Russian Federation No. 075-00087-2401.

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