Thermal shock characterization of tungsten deformed in two orthogonal directions

The increasing importance of tungsten and tungsten alloys for future nuclear fusion facilities and reactors requires an increasing understanding of the materials behavior under operational loading conditions. Among others this comprises the thermal shock and thermal fatigue resistance of the material before and after recrystallization. This study in particular aims for the qualification of deformed tungsten forged in two orthogonal directions intending to obtain a dense and nearly isotropic grain structure. The material is investigated in its stress relieved and recrystallized state and acts as a reference material for a better understanding of the cracking process when exposed to transient thermal loads, e.g. Edge Localized Modes (ELMs: fP1 Hz, t = hundreds of ls). This is addressed by multiple thermal shock loadings in the electron beam facility JUDITH at different base temperatures. Hereby the influence of the DBTT on the onset of crack formation is verified and the latter qualified and quantified by metallographic means.