| dc.description.abstract | The phenomenon of recrystallization and corresponding texture evolution in metallic systems has been studied for several decades yet not understood completely. The complexity of the problem arises due to its dependence on several factors such as crystal structure, the composition of material, stacking fault energy, deformation texture, pre-deformation parameters, annealing parameters, etc. Hence, a systematic study on the evolution of recrystallization texture considering the effect of all these factors is highly desirable. In the present study, a close examination reveals that most of these factors are interrelated. Moreover, microstructural features and texture prior to recrystallization play a significant role in deciding the evolution of recrystallization microstructure and texture. These two factors are directly related to the stacking fault energy of the material. Hence a study elucidating the role of stacking fault energy on the development of texture would encompass the mechanisms of evolution of recrystallization texture.
In the present investigation, two types of alloy systems have been investigated: the Ni-Fe alloy system, where alloying addition does not affect stacking fault energy, and the Ni-Co alloy system, where alloying addition leads to systematic variation in stacking fault energy. After recrystallization, the Ni-Fe alloys show non-uniform α-fiber recrystallization texture. In the case of Ni-Fe, the addition of alloying leads to some fine differences in the recrystallization texture, which has been attributed to the highly heterogeneous deformed microstructure resulting after alloying. The Ni-Co alloys also show non-uniform α-fiber recrystallization texture with the exception of Ni-20Co, and Ni-60Co alloys, where a relatively uniform α-fiber recrystallization texture evolves. It is attributed to the inherent heterogeneity of the as-deformed microstructures. In all the cases, the entire recrystallization stage is dominated by the formation of the annealing twin (Σ3) boundary. The mechanism of evolution of recrystallization texture in each case and the role of different deformation feature during recrystallization has been investigated in detail. The cellular automata simulation technique has been used to simulate the different phenomena during the recrystallization process. The evolution of recrystallization microstructure, texture, kinetics, and grain size distribution has been simulated. | en_US |
