[3H01-06] Irradiation Behavior

[3H05] Responses of binary tungsten alloys to heavy ion irradiation

*Yuji Hatano¹, Jing Wang^1,4, Takeshi Toyama², Tatsuya Hinoki³, Kiyohiro Yabuuchi³ (1. Univ. of Toyama, 2. Tohoku Univ., 3. Kyoto Univ., 4. Hefei Inst. Technol.)

Keywords:Divertor, Tungsten, Radiation effects, Alloying

W and W-based binary alloys (W-0.3Cr, W-2.5Mo, W-5Ta and W-5Re) were irradiated with 6.4 MeV Fe ions at 800 C to 0.26 dpa using DuET at Kyoto University. Then, vacancy concentration, hardness and microstructure were examined using positron annihilation, nano-indentation and atom probe tomography, respectively. Significant increase in positron lifetime due to vacancy formation was observed for W, W-2.5Mo and W-5Ta, while precipitation occurred in W-0.3Cr and W-5Re. The extent of radiation hardening was W-5Ta > W > W-2.5 Mo > W-0.3Cr > W-5Re. It was concluded that the suppression of vacancy formation by addition of Re and Cr can improve mechanical properties after irradiation under certain conditions, but precipitation hardening is more serious for Cr than Re.