2018/09/20 by R.D. Smirnov, S.I. Krasheninnikov, S. I. Krasheninnikov · 2 citations
Materials Science · #Fusion materials and technologies #Nuclear Materials and Properties #Hydrogen embrittlement and corrosion behaviors in metals
paper · doi:10.1088/1741-4326/aae2c7
The molecular dynamics simulations of trapping of hydrogen atoms in tungsten are presented. The simulations reveal formation of platelet-like structures of self-trapped hydrogen induced by stresses in tungsten, in particular, those produced by dislocations, at the interstitial hydrogen concentrations ~0.3-1 at.%. The spontaneous hydrogen platelet formation in absence of dislocations and external stresses has been also observed at the higher hydrogen concentrations ~10 at.%. It is shown that the platelets can retain substantial quantities of hydrogen, exceeding trapping capacity of other non-cavity defects in tungsten. The properties of the hydrogen latelets formed in tungsten under various conditions are assessed and a formation mechanism is proposed. A model of hydrogen retention by the dislocation-induced structures is also presented, which describes retained quantities and outgassing dynamics of hydrogen in plasma exposed tungsten samples.