The Influence of Electron-Beam Processing on the Formation of the Structure and Surface Properties of AK10M2N Alloy Destroyed under Tensile Conditions

Abstract

Transmission electron-microscopy methods were used to study structural-phase transformations occurring after electron-beam treatment of samples of AK10M2N alloy subjected to uniaxial tension, and the defective substructure of the samples was studied. The studies were carried out on samples of AK10M2N aluminum alloy manufactured by electrical discharge cutting that had been subjected to electron-beam processing of the surface layer and samples in the cast state to identify the dynamics of the structural-phase state and differences in destruction mechanisms. Previously, the most rational mode for irradiating samples was identified (electron beam energy density 50 J/cm², pulse duration 200 μs). A fractographic analysis of the fracture surface of samples in the cast state and subjected to electron-beam processing was performed. As a result of fractographic analysis, the mechanism of brittle fracture in cast samples of AK10M2N alloy was revealed. Foci of destruction in the structure of a brittle fracture in the form of intermetallic compounds of various shapes and structures have been identified. In the sample irradiated at an electron beam energy density of 50 J/cm² with a pulse duration of 200 μs, a fracture analysis was also carried out. The formation of an intercrystalline (intergranular) fracture after irradiation with an electron beam was revealed. A change was detected in the defective substructure of the AK10M2N alloy destroyed under tensile conditions (cast state and state formed after electron-beam processing). Electron-beam processing leads to the formation of a relatively thin surface layer represented by a submicronanocrystalline multiphase structure. Analysis of microelectron diffraction patterns made it possible to establish that the main phase located along the boundaries of crystallization cells is silicon. In addition, particles of complex composition Al₂₃CuFe₄ were discovered in the volume of crystallization cells. Based on the research that was carried out, an assumption was made about the mechanism for increasing the strength of irradiated silumin (relative to the cast state).