Orientation Relationships between Grains during Dynamic Recrystallization of Polycrystalline Nickel

Abstract

Microscopic observation on dynamic recrystallization in polycrystalline nickel and the orientation analysis of individual grains have been conducted by using electron channeling patterns.
Originally existing grain boundaries began to bulge out at a strain of 0.5ε_p and new grains began to come out along grain boundaries at a strain of 0.75 ε_p, where ε_p is the peak strain corresponding to a maximum flow stress. It was found that only a few grains were produced by a bulging or a multiple twinning process. This is at variance with the observations on single crystals or a coarse-grained austenitic steel.
The growth rate of new grains was seemingly independent of the orientation relationships in their growth fronts. This trend is in contrast to the static recrystallization. The reason for this difference is discussed in special reference to the concurrent straining during the recrystallization.