Drag effect of triple junctions on grain boundary and grain growth kinetics in aluminium

The motion and geometry of connected 2D grain boundary systems with triple junctions in aluminium was investigated in situ in an SEM with a specially designed heating stage. The results show that triple junctions can have a marked influence on grain boundary motion and grain growth kinetics. The grain area change with annealing time was recorded in situ in the SEM. An analysis of the experimental data reveals that there is no unique relationship between growth rate and the number n of grain sides (von Neumann-Mullins relation). This is attributed to the effect of triple junction drag on grain growth.