34.10 Basic Features of The Plastic Deformation of Polycrystals Basic distinction between single crystal and polycrystals (1 A great deal of grains with different orientation ② Grain boundary G B is a thin layer of material between neighboring grain where atoms arranged in transitional position§4.10 Basic Features of The Plastic Deformation of Polycrystals Basic distinction between single crystal and polycrystals ① A great deal of grains with different orientation ② Grain boundary G.B. is a thin layer of material between neighboring grain where atoms arranged in transitional position