Effect of Pulsed Helium Ion Fluxes and Helium Plasma on the Inconel 718 Alloy

Abstract

The results of the irradiation of the Inconel 718 alloy with pulsed helium ion and helium plasma fluxes at a power density q = 10⁷ W/cm² and a pulse duration τ ≈ 100 ns in the Vikhr Plasma Focus setup are presented. The surface layer is not melted under the irradiation conditions. However, a slight increase in q causes melting of local regions in the surface and the formation of a wavy relief. Beam–plasma irradiation results in structural and phase changes in the irradiated surface layer, namely, the precipitation of microinclusions (complex niobium carbides), a redistribution of alloy elements, a slight decrease in the microhardness, and, accordingly, slight softening. These changes in the microstructure and the properties are determined by the melting of the irradiated surface in local regions, partial sputtering of solid-phase regions, and recrystallization in the near-surface layer during pulsed heating for each beam–plasma action.