摘要
将多态相场(MSPF)模型与品格畸变模型结合,根据合金的储存能分布,应用于亚晶组织的演化研究.通过构造变形晶粒的初始亚晶组织,计算模拟再结晶过程中亚晶通过合并与吞噬机制进行长大的微观演化过程,系统研究了变形量对亚晶尺寸分布和亚晶长大速率的影响.结果表明,在储存能较高的区域(如晶界附近处),亚晶较细小,分布较密集;再结晶过程中,亚晶密度高的区域最先出现亚晶合并和吞噬现象,并通过该机制使再结晶晶粒形核和长大;而在变形晶粒内部,亚晶分布较均匀且数量密度低,尺寸较大,亚晶合并长大的速率较慢.再结晶晶粒尺寸权重概率分布表明,变形量大的合金,晶粒尺寸较快地变大,完成再结晶的时间较短,而变形量较小的合金,晶粒尺寸变化较慢,再结晶完成的时间较长.亚晶组织演化的模拟结果与实验结果相符.
It is well know that static recrystallization （SRX）, which occurs during post- deformation annealing, is greatly affected by the deformation formed during cold working. Therefore, to investigate and predict the SRX microstructure and SRX texture numerically with high accuracy, it is necessary to simulate the SRX process taking the deformation mierostructnre into consideration. A model that couples the crystal plasticity finite element method and microstructure evolution model is believed to be the most promising approach for SRX microstructure design. In this paper, the subgrain structure evolution is firstly studied by using the multi-state phase field （MSPF） model coupling with the lattice deformation model including the stored energy distribution of deformed alloy. The ini- tial subgrain growth through the mechanism of mergence and swallow during recrystallization process are simulated by MSPF. The different amount of deformation effecting on subgrain distribution and subgrain growth rate are studied systematically. The calculated results show that in the region with higher stored energy, for example, around grain boundaries, there are very dense finer subgrains which recrystallize earliestly in the higher stored energy region during recrystallization process, and grow up by mergencing and swallowing, while the distribution of subgrains inside the deformation grain is relative uniform and with relative large subgrains which grow up slowly. The distribution of grainsobtained by the weighted frequency shows that the grain distribution changes from small to large grain is fast for the larger deformed alloy, while the change is slow for the less deformed alloy. All the results are agreement with experimental ones.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第10期1215-1222,共8页
Acta Metallurgica Sinica
基金
国家自然科学基金项目51161003和50661001
广西自然科学基金重点项目2012GXNSFDA053001
广西研究生创新计划项目105931001015资助~~
关键词
相场模型
亚晶
塑性变形
镁合金
phase field model, subgrain, plastic deformation, Mg-based alloy
