Abstract Scope |
Fusion structural materials often transmute under 14.1 MeV fast neutrons, producing helium which embrittles the grain boundary network. Here, it is shown that neutron-friendly and mechanically strong nano-phases with atomic-scale free volume can have low He-embedding energy and >10at% He-absorbing capacity, and can be especially advantageous for soaking up He on top of resisting radiation damage and creep, provided they have thermodynamic compatibility with the matrix phase. Experimental demonstration proves that Eemb is a good ab initio predictor of He shielding potency in nano-heterophase materials. A list of compounds expected to be good He-absorbing nano-phases is presented, taking into account Eemb, the neutron absorption and activation cross-sections, the elastic moduli, melting temperature, the thermodynamic compatibility, and the equilibrium wetting angle of the nano-phases with the Fe matrix. [Adv. Sci. 9 (2022) 2203555; "Machine learning in nuclear materials research," Current Opinion in Solid State and Materials Science 26 (2022) 100975] |