Erosion study of Fe-W binary mixed layer prepared as model system for RAFM steel

Fe-W binary mixed layers were prepared as a model system for reduced-activation ferritic-martensitic (RAFM) steel for studying their dynamic erosion behavior resulting from energetic deuterium (D) irradiation. This investigation aims toward an assessment of RAFM steels as plasma-facing material. The surface composition of the model layers is modified by D irradiation. W is enriched at the surface with D irradiation fluence due to the preferential sputtering of Fe. It depends on the D impinging energy as well as the initial W fraction of the Fe-W layer. No significant development of surface topography was observed within the examined conditions. The erosion yield of a Fe-W layer is comparable to that of pure Fe in the low-fluence range and decreases with increasing D fluence. These results indicate that the dynamic change of erosion yield is significantly correlated with the surface W enrichment.