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

Effect of Pulsed Ion-Plasma Impact and Electron Irradiation on Mechanical Properties of Precipitation-Hardened Inconel 718 Alloy

“…Thus, in general, from the results of our investigation, we can come to the conclusion that pulsed ionplasma irradiation with a maximum fluence of ~3 × Here, we should take into account the fact that 20-MeV electrons lead to radiation damage over the entire volume of the irradiated samples, while ionplasma treatment affects only a very thin (50-100 nm) surface layer of the sample in which some redistribution of alloying elements, increase in the size of micropores, and formation of precipitates of complex carbides and intermetallic compounds occur [6]. The absence of an effect of electron irradiation on the mechanical properties of the Inconel 718 alloy seems to be quite justified, taking into account a small irradiation dose.…”

“…The Inconel 718 alloy is obtained by selective laser fusion of 45-μm powder according to the technology described in [6]. After fusion, the thermal treatment standard for precipitation hardening of the Inconeltype alloys (hardening + aging) was carried out.…”

“…Irradiation of the samples at the PF setup was carried out according to the procedure described in [6] in a hydrogen atmosphere under the conditions excluding the surface melting. The total number of irradiation pulses with a duration τ = 100 ns was N = 15 and 30; the distance from the PF anode to the sample-target was 7.5 cm; the radiation power density in each pulse reached q = 10 7 W/cm 2 ; the fluence for one pulse was Φ > 10 17 cm -2 .…”

“…During the pulsed discharge, the sample was subjected to the impact of high-temperature plasma (T pl ≈ 0.3-1.0 keV) with a density n pl ≈ 10 19 cm -3 and to the hydrogen-ion flow with a peak energy E i ≈ 0.1 MeV. According to estimates [6], for one pulse, the sample surface was heated up to ~1000-1200°C, which was lower than the melting point of the alloy (1260-1340°C).…”

“…In [6], the structure of the Inconel 718 alloy after irradiation with pulsed helium-ion fluxes and helium plasma was studied at the Vikhr Plasma Focus (PF); however, no investigations of the influence of irradiation on the mechanical properties of the alloy, except for measuring its microhardness, were carried out.…”