(CrVW)x(TiTa)y as thermal barrier for nuclear fusion

11/26/2024

High entropy alloys have recently been studied for nuclear fusion applications, particularly inside the divertor in nuclear reactors, such as tokamak. Due to the mismatch of the operating temperatures between the plasma-facing wall made of W monoblocks and the heat sink made of CuCrZr inside the divertor, a compatible thermal barrier interlayer is required for the durability of the nuclear reactor. These alloys provide outstanding thermal and mechanical properties and high irradiation resistance - everything required for thermal barrier applications. In this work, the (CrVW)_x(TiTa)_y (x=90% and 80%, and y=10% and 20%, respectively) alloys were produced by mechanical alloying (MA), followed by spark plasma sintering (SPS), and arc melting (AM). Thermal analysis was performed in the samples consolidated by SPS, confirming their thermal stability up to 1250ºC. All samples were characterized by scanning electron microscopy and by X-ray diffraction. The (CrVW)_90(TiTa)_10 sample consolidated by SPS revealed a BCC solid solution, in line with the thermodynamic calculations, and with a peak intensity inversion after annealing treatment. The same composition by AM revealed a BCC structure. The (CrVW)_80(TiTa)_20 sample consolidated by SPS showed a dominant BCC solid solution, also in line with the thermodynamic calculations but with a minor FCC structure. After annealing, this sample demonstrated a dominant C14 Laves phase. In addition, the same composition by AM also revealed a BCC structure.

Authors in the community:

• 

  S

  Sofia Jardim Gonçalves Barreto de Lara

  ist192995

Supervisors of this institution:

• 

  N

  Norberto José Sobral Catarino

  ist25572

• 

  M

  Marta Sofia Rosado Silva Dias

  ist46980

mechanical-engineering - Mechanical engineering

por - Portuguese

Instituto Superior Técnico