Monte-carlo modeling of grain growth in Zr equal channel angular pressed and recrystallized

Abstract

Grain boundary character distribution in equal-channel-angular pressed Zr was studied. Using a die design of 90 o /20 o and an operation temperature of 350 o C. The initial grain size of 20 μm was reduced to about 270 nm with 4 passes via route B C . The grain growth kinetics of the recrystallized state was obtained by experiment and Monte-Carlo computer simulation, respectively, which showed good agreement. Based on kinetics and morphological characteristics, it was concluded that the grain coarsening mechanism was governed by normal grain growth. No sign of abnormal grain growth was detected either in the experiment or in simulation despite taking into consideration anisotropy in grain boundary energy as well as its mobility. This indicates that grain boundaries produced by severely deformed Zr are stable against explosive coarsening. The evolution characteristics of the microstructure in the present ECA pressed and recrystallized Zr differed from those of cold rolled Ti in that the grain boundary misorientation distribution and texture were rather stable during grain growth.