Grain boundary and particle interaction: Enveloping and pass-through mechanisms studied by 3D phase field crystal simulations

Grain boundary interaction with second-phase particles having different degrees of coherency is investigated using the phase field crystal (PFC) method. Both the enveloping and pass-through mechanisms are studied with regards to grain boundary pressure, passage time and interface evolution. It is found that coherent particles exert a stronger retardation effect on grain boundaries compared to incoherent particles, with regards to both pressure and time, but also that this benefit is limited to a small range of misfit values. The simulations also show that the mobility is not a constant during particle passage, as commonly assumed, which means that grain boundary pressure cannot easily be extracted from the grain boundary velocity. Furthermore, the complex evolution of the pass-through mechanism and the transient behavior for intermediate coherencies is also investigated. The highest drag force is found to occur at the switching point between enveloping and pass-through. As part of the study, the advantages of using PFC for this type of analyses are also highlighted.