Study on material damage in the high energy quantum beam fields and development of high performance materials, 9; Effect of multi layered surface treatment on pitting damage

Naoe, Takashi   ; Futakawa, Masatoshi  ; Kawai, Masayoshi*; Yamamura, Tsutomu*; Igarashi, Tadashi*

Mitigation of the pitting damage formation induced by the pressure wave in mercury is the most important issue to realize the MW-class spallation neutron source in J-PARC. From the viewpoint of the material approach, to mitigate the localized impact by cavitation and fatigue strength degradation due to the cavitation induced microcrack propagation, we focused on a multilayered surface treatment. Optimized multilayered surface which effectively reduced damage formation was designed by numerical calculation. Furthermore, the effects of multilayered surface treatments were experimentally evaluated by the pitting damage tests in mercury with the diffusion bonded specimen.