STRUCTURE, PHASE COMPOSITION AND PROPERTIES OF HIGH-ENTROPY AlCrFeCoNi ALLOY IRRADIATED WITH A PULSED ELECTRON BEAM

Volumetric samples of a high-entropy alloy of nonstoichiometric composition were produced by the method of wire-arc additive manufacturing (WAAM). In this work, the methods of modern physical materials science have been used to analyze the elemental and phase compositions, defective substructure and tribological properties of the HEA surface layer formed as a result of irradiation with a pulsed electron beam with different electron beam energy densities (10 – 30 J/cm²) in an argon medium. It is shown that irradiation does not depend on the energy density of the electron beam and leads to fragmentation of the surface by a network of microcracks, which indicates an increased fragility of the alloy under study. The homogenization of the alloy and the formation of a submicro- and nanocrystalline structure are noted. The thickness of the modified layer increases from 0.8 to 20 µm with an increase in the energy density of the electron beam from 10 to 30 J/cm². The correlation of changes in nanohardness and modulus of elasticity with the results of measuring microhardness has been established. The correlated decrease in micro- and nanohardness and Young’s modulus indicates relaxation of the internal stress fields formed during the manufacture of the alloy. Electron beam treatment has little effect on tribological properties, but significantly increases the strength and ductility of the material. The highest value of the compressive strength of 2179 MPa was obtained in an alloy treated with an electron beam with an energy density of 30 J/cm². The conditional yield strength for compression was 522 MPa, and the Young’s modulus was 257 GPa.

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