An investigation was made of the steady-state motion of grain boundaries, especially <111> and <110> tilt boundaries, in high-purity samples. The results demonstrated that the motion of grain boundary systems with triple junctions could be controlled by slowly-moving triple junctions. The effect of the triple junctions depended upon temperature, and was particularly marked at low temperatures. At high temperatures, the motion of a connected grain boundary system was less affected by the triple junctions and was therefore effectively controlled by the grain-boundary mobility. The results revealed a marked difference between the activation enthalpies of grain-boundary and triple-junction motion. There was therefore a temperature below which triple junctions governed the motion of the connected boundary system. This temperature depended upon the grain boundary and triple junction geometry.

Triple Junction Motion in Aluminium Tricrystals. S.G.Protasova, G.Gottstein, D.A.Molodov, V.G.Sursaeva, L.S.Shvindlerman: Acta Materialia, 2001, 49[13], 2519-25