[1L06-09] Engineering for Divertor 2

11:05 AM - 11:20 AM JST(2:05 AM - 2:20 AM UTC)

[1L07] Fracture toughness evaluation of Zr added W-Y₂O₃ alloy

*Taiki Shimoda¹, Kazutoshi Tokunaga¹, Satoru Matsuo², Hiroaki Kurishita³, Takeshi Toyama⁴, Laima Luo⁵, Qiu Xu⁶ (1. Kyushu Univ., 2. Tohoku Univ., 3. KEK, 4. JAEA, 5. Hefei Univ., 6. Kyoto Univ.)

Keywords:

Tungsten alloy,Fracture toughness,Fatigue pre-crack introduction

Tungsten (W) is a candidate material for the surface of fusion reactor divertors. However, it suffers problems of embrittlement caused by lowered temperature, recrystallization and exposure to irradiation. To mitigate these problems, additions of transition metal carbides such as TiC and oxides such as Y₂O₃ have been employed. Furthermore, improvements in mechanical properties have been reported with the addition of elements like Mo or Zr. This study deals with the fracture toughness of a W-0.1Zr-0.25 Y₂O₃ alloy, which was fabricated by spark plasma sintering of precursory powder processed via the wet-chemical method. Notched W-0.1Zr-0.25Y₂O₃ alloy specimens were subjected to pre-cracking by compression fatigue and subsequent three point-bend fatigue prior to fracture testing. The results were compared with those of ITER-grade rolled tungsten.