SIMULATION OF RECRYSTALLIZATION MICROSTRUCTURES AND TEXTURES - EFFECTS OF PREFERENTIAL GROWTH

Three-dimensional (3-D) simulations of recrystallization were carried out using an approach where grains of different orientations are chara cterized by different nucleation and growth parameters. The aim was, b y simulation, to study the effects of preferential growth on recrystal lization under various nucleation assumptions. The simulations were ba sed on the assumptions that (1) a material can be represented by two t ypes of grains, one that grows 1.5 to 2.5 times faster than the other type; (2) the nucleation takes place either instantaneously when annea ling is started or continuously during the annealing period; and (3) t he nucleation sites are distributed either randomly or in clusters (ar ound points, along lines, or on planes). These assumptions relate to c ommon experimental observations. It was found that the nucleation and growth assumptions have very significant influences on the recrystalli zation characteristics. The preferential growth of one type of grain i n particular affects the width of the recrystallized grain size distri bution and the texture development. Furthermore, it was found that man y different nucleation and growth assumptions can result in identical recrystallization microstructures and textures. The results of the sim ulations are discussed with reference to typical experimental findings .