Irradiation induced creep in nanocrystalline high entropy alloys

Irradiation induced creep (IIC) compliance in NiCoFeCrMn high entropy alloys is measured as a function of grain size (30 < x < 80 nm) and temperature (23–500 °C). For 2.6 MeV Ag3+ irradiation at a dose rate of 1.5×10–3 dpa−1s−1 the transition from the recombination to sink limited regimes occurs at ∼ 100 °C. In the sink-limited regime, the IIC compliance scales inversely with grain size, consistent with a recently proposed model for grain boundary IIC. The thermal creep rate is also measured; it does not become comparable to the IIC rate, however, until ∼ 650 °C. The results are discussed in context of defect kinetics in irradiated HEA systems.