Papers by Author: Lasar S. Shvindlerman

Abstract: The motion and geometry of connected grain boundary systems with triple junctions in aluminium -10 ppm magnesium was investigated in-situ with a special designed SEM heating stage. The results show that triple junctions can have a marked influence on grain boundary motion. The grain area change with annealing time was from a hot stage 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.

Abstract: The motion of a curved grain boundary with a “surface triple junction” (“free surface – boundary - free surface”) in aluminum bicrystals is studied. The effect of the “surface triple junction” on grain boundary motion is discussed in the terms of the equilibrium of boundary and junction velocity. Boundary motion in samples with different boundary curvature revealed a strict proportionality of boundary velocity and driving force. This result corroborates the fact that in the entire investigated temperature range the “surface” triple junction does not affect the boundary motion.

Abstract: The motion of <111> tilt and mixed tilt-twist grain boundaries with misorientation angles in the range between 34° and 42° in pure Al bicrystals was measured over the temperature range between 310 and 610°C. The experiments revealed that the change of the set of boundary planes in the curved moving tilt boundary does not affect its motion. The shape of the curved moving part of the mixed tilt-twist boundary was measured and compared with analytically calculated boundary shape. The results have shown that an increase of the twist component along the curved mixed boundary in studied geometrical configuration does not affect its steady-state motion. Similar to the behaviour of <111> pure tilt boundaries, the mobility of <111> mixed tilt-twist grain boundaries in the vicinity of special misorientation å7 depends on the misorientation angle in a non-monotonic fashion.