摘要
为了研究形核机制对多晶金属材料热加工过程的影响,通过建立动态再结晶的二维元胞自动机模型,模拟了3种形核机制下动态再结晶组织的演化过程,得到了热加工过程中再结晶平均晶粒尺寸的变化规律及生长动力学特征.模拟结果表明,再结晶平均晶粒尺寸的变化规律由形核机制和生长方式共同决定,但稳态时的平均晶粒尺寸只与总的形核数目有关;生长动力学曲线均呈S形,其变化规律符合JMAK理论;Avrami指数的大小取决于晶核的空间分布.
In order to study the effect of nucleation mechanism on the hot working process of polycrystalline metals, the evolvement of dynamic recrystallization microstructure under three nucleation mechanisms was simulated by developing a two-dimension cellular automaton model. The variation of the mean size of recrystallization grains（R-grains） and the characteristics of growth kinetics during the hot working process were obtained. The simulated results of the three models were discussed and compared together. It is found that the variation of the mean size of recrystallization grains is decided by the nucleation mechanism and the growth mode. However, the steady mean size only depends on the total number of nuclei. The curve of the growth kinetics looks like the shape of ＂S＂ and its variation follows the JMAK theory. The Avrami exponent is decided by the spatial distribution of nuclei.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2008年第3期351-355,共5页
Journal of Dalian University of Technology
