SURFACE EFFECTS ON RECRYSTALLIZATION AT D EFORMATION BANDS IN ALUMINUM SINGLE-CRYSTALS DEFORMED IN TENSION

Effects of free surface on the formation of recrystallized grains were discussed in terms of the differences in the deformation structure, r ecovery process, and total energy of grain boundaries around a recryst allization nucleus between the surface and inner layers in an aluminum single crystal with a Schmid factor of 0.5. For this purpose, the spe cimens were deformed in tension to the strain of 0.5 and subsequently annealed. During the annealing, the existence of the free surface prom otes the formation of recrystallized grains in the surface layer. It i s concluded that the recovery of deformed structures with a high densi ty of dislocations is easier and the total energy of grain boundaries around a nucleus of recrystallization is smaller in the surface layer than in the inner layer.