Lecture No.128

Title: Line Tension of Grain Boundary Triple Junction in Copper


Speaker: B. Zhao, L. S. Shvindlerman, G. Gottstein

         Institute of Physical Metallurgy and Metal Physics

         RWTH Aachen University, Aachen, Germany


Date/Time: 2013-12-24,10:00


Venue: Room.308, Material Building A


Inviter: Prof Lanting ZHANG



   Recent studies have demonstrated that grain boundary triple junctions are crystal defects on their own with specific thermodynamic and kinetic properties which can strongly impact microstructural development. A thermodynamically correct approach is put forward in the current study, which allows a direct and precise measurement of the triple line tension. The investigation is achieved by the measurement of the force equilibrium at a triple junction as established by the curvature of the adjourning grain boundary grooves at the root of the triple junction. The experimental technique utilizes the measurement of the surface topography of a crystal in the vicinity of a triple junction by atomic force microscopy (AFM). The corresponding measurements based on copper bicrystal and tricrystal show that the line tension of grain boundaryfree surface is in the order of J/m, while the line tension of grain boundary triple junction is positive and in the order of 10-9 J/m.


Location:Room .308 Material Building A