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The structural-phase state of the AlCoCrFeNi high-entropy alloy obtained by laser alloying of technically pure aluminium surface layers with a mixture of powders of pure elements Fe, Co, Ni, Cr in an equiatomic ratio is investigated by X-ray phase, X-ray spectral, and metallographic analyses. As shown, in the process of laser alloying the formation of a heterophase structure, which consists of an ordered multicomponent substitution solid solution based on b.c.c. lattice and Al 13 (Me) 4 monoclinic intermetallide, take place. As established, the formation of such a structure is a consequence of melt high cooling rates, high aluminium content and inhomogeneous distribution of chemical components in the surface and bottom layers of the laser alloying zone. The microhardness of the alloyed surface is 4.7 GPa, which is typical for high-entropy alloys of this system obtained by other methods. Additional reasons that may affect the high values of microhardness are analysed.

The structural-phase state of the CoCrFeNi high-entropy alloy obtained by laser alloying of technically pure iron surface layers with a mixture of powders of pure elements Co, Ni, Cr in an equiatomic ratio was investigated by XRD, EDX and metallographic analyses. As shown, the formation of multicomponent substitutional solid solution based on f.c.c. lattice, which is typical for high entropy alloys in the surface layers during laser alloying took place. The influence of the atmosphere, in which alloying is carried out, on the processes of structure formation and phase composition of alloyed surfaces are analyzed. As determined, during laser alloying in the air exothermic oxidation processes occurs, which, as a result, lead to the formation of oxygen-and chromium-enriched areas on the peripheral areas of laser spots. Laser alloying in argon atmosphere provides a uniform distribution of all elements on the surface of the laser alloying zone.

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