Simulation of γ-hydride precipitation in bi-crystalline zirconium under uniformly applied load

The morphology evolution of γ-hydride precipitation and growth in a zirconium bi-crystal was simulated using a phase field kinetic model. The effects of grain boundary and uniformly applied load were studied. The temporal evolution of the spatially dependent field variables is determined by numerically solving the time-dependent Ginzburg–Landau equations for the structural variables and the Cahn–Hilliard diffusion equation for the concentration variable. It is demonstrated that nucleation density of the hydride at the grain boundary increases as compared to the bulk and favorable hydride precipitation at the grain boundary become weaker when an external load is applied. The result also showed that hydrides will grow in those habit planes that are near the perpendicular direction of the applied tensile load.