A new type of plasma irradiation-resistant amorphous TiZrHfTaW refractory multi-component alloy

Developing high performance plasma facing materials (PFMs) is one of the greatest challenges for fusion reactors because PFMs face unprecedented harsh environments. In this work, the radiation resistance of tungsten-containing amorphous refractory multi-component alloy film was studied by He plasma irradiation. The amorphous TiZrHfTaW film was evaluated by 50 eV helium plasma irradiation at 1275 K. The invaded helium atoms quickly diffuse inside the film delaying the formation of large He bubbles near surface and its break to form fuzz. Instead, He migrates and merges to form large number of relatively small helium bubbles, leading to the formation of nanoporous structures, which blocks the diffusion of He. This new "migration-blocking" strategy in the amorphous TiZrHfTaW film greatly slowing down the growth of fuzz. The threshold fluence for forming fuzz structure in TiZrHfTaW film is increased greatly to 20 times higher and the length of fuzz irradiated to the fluence of 3 × 10²⁶ ions/m² is 28 times shorter than those of bulk W. The presented results provide an idea for development of amorphous refractory multi-component alloys as a new kind of radiation resistant PFMs and trigger further study on it.