Microstructural evolution during directional annealing

Experiments and simulations of directionally annealed ODS MA 754

“…It is worth noting that large equi-axed grains were observed experimentally during directional recrystallization of copper at very low hot-zone velocities [36], whereas the front-tracking model did not reproduce this behavior [29]. This is due to the infinite temperature gradient used in the simulation, which is not present in the experiments.…”

“…Details of the simulation technique using the front-tracking model, where a narrow infinite hot-zone travels along the specimen from one end to the other end have been given elsewhere [29]. Briefly, if the grain boundary velocity, v, is defined as:…”

“…(2) somewhat elongated grains (intermediate hot-zone velocities); or columnar grains (low hot-zone velocities) [29]. It is worth noting that large equi-axed grains were observed experimentally during directional recrystallization of copper at very low hot-zone velocities [36], whereas the front-tracking model did not reproduce this behavior [29].…”

“…The second technique is the front-tracking, curvature-driven model, which was initially programmed by Frost et al [1]. This model has been successfully used to simulate both normal and abnormal grain growth in thin films [24,25], directional recrystallization without particles [ [26][27][28][29][30], and the effects of variable grain boundary energy and mobility, and, thus, to some extent, textures. In addition, secondphase particles have been introduced into this model to simulate their effects on isothermal grain growth [31,32].…”

Processing and High Temperature Properties of Nb/Nb5Si3 Laminates

“…Baker et al [8] have shown that discontinuous grain growth occurs during the recrystallization of Cu under a large thermal gradient. We investigated whether the crystallization of the NbsSis would exhibit a similar response to large thermal gradients.…”