Phase-field modelling of stress driven precipitation
The increasing usage of hydrogen as fuel for vehicles and as a mean to store energy requires secure vessels for transport and storage of liquid hydrogen.Metals like aluminium, iron, magnesium, titanium and zirconium become brittle in hydrogen environments. This is a serious problem when it affects structural components. In many applications, hydride embrittlement is foreseen as a life limiting factor. It is proposed to extend the understanding of the texture evolution both without and under applied stress in single phase or alloys. The suggested method is phase field calculations of accumulation of hydrogen and the phase transformation from metal to hydride. The driving forces that will be accounted for is strain energy, gradient energy and the Landau chemical potential. Focus will be on hydride formation at crack tips. Stress distribution, shielding effects and the observed fragmentation into hydride platelets will be analysed.