2-DIMENSIONAL NORMAL GRAIN-GROWTH - TOPOLOGICAL ASPECTS

Normal grain growth in polycrystals is an important example of a capil larity driven coarsening phenomenon where topological structure of the system plays a major role. The process is practically important and a ttracts much interest, in particular in two-dimensional (2D) polycryst als because of the growing technological importance of thin polycrysta lline films. In the present paper we discuss various approaches to nor mal grain growth in 2D polycrystals. We stay mostly within the framewo rk of the uniform boundary model. This model provides a reasonable sim plification leading to the Von Neumann-Mullins relation that relates t he rate of growth of an individual grain to its local topology. Compar ing different approaches-relatively simple mean-field theories, more s ophisticated models incorporating real topology, and computer simulati ons adequately reproducing local equations of motion-we identify the p rincipal factors responsible for different features of the phenomenon.