Electron-ion-plasma surface modification of hypereutectic silumin

Abstract

In this study, an integrated treatment approach was employed to modify hypereutectic silumin. This method involved electroexplosive alloying of the surface layer with yttrium oxide powder, followed by irradiation with a pulsed electron beam. The experimental data obtained demonstrate that this integrated treatment results in the formation of a submicron-nanocrystalline structure characterized by high-speed cellular crystallization of aluminum within the surface layer. This structure is composed of crystallization cells enriched with aluminum atoms, indicating the creation of a solid solution based on aluminum. The nanocrystalline layers, formed by silicon particles and yttrium oxide, are positioned at the cell boundaries. The study reveals that, as a consequence of integrated treatment with an electron beam energy density of 25 J/cm2 , the wear parameter of the modified samples increases by 7.9±0.6-fold, and the friction coefficient decreases by 1.7±0.15-fold compared to the initial state. Additionally, the microhardness of the modified silumin surface layer increases by 1.5±0.12-fold compared to the initial state. When the electron beam energy density is elevated to 35 J/cm2, the wear parameter of silumin is enhanced by 2.1±0.21-fold, while the friction coefficient increases by 1.13±0.1-fold. However, the microhardness decreases by 1.3±0.13-fold, while still surpassing the specified characteristics of untreated silumin. This investigation postulates that the substantial increase in the wear parameter during integrated treatment may be attributed to the presence of silicon inclusions in the surface layer that did not dissolve during the modification process. These inclusions are surrounded by the high-speed cellular crystallization structure mentioned earlier.