摘要
运用大规模的分子动力学模拟研究了厚度和晶粒取向对纳米晶Al薄膜Bauschinger效应的影响.模拟结果表明:晶粒取向的不均匀性对早期Bauschinger效应及相关塑性变形机制有显著的影响.相对于没有织构的薄膜试样而言,尽管晶粒尺寸、形状和厚度相同,具有(110)织构的薄膜表现出较轻微的Bauschinger效应.同时,分子动力学模拟也揭示早期Bauschinger效应起源于卸载过程中位错的反向运动和由于位错反应造成位错密度的降低.这些位错机制是由加载过程中产生的不均匀变形引起的内在残余应力所驱动的.
The early Bauschinger effect in nanocrystalline A1 thin films with different thicknesses and microstructural orientations was investigated using large-scale atomistic simulations. The simulation results indicate that the microstructural orientation heterogeneity has a significant influence on the early Bauschinger effect and the as- sociated plastic deformation mechanisms. The （110）-textured thin films show less Bauschinger effect compared to non-textured films despite having the same grain size, shape and thickness. The atomistic simulations reveal that the early Bauschinger effect originates from the reverse motion of dislocations and the reduction in dislocation den- sity due to dislocation reactions during unloading, which are driven by the internal residual stress caused by the in- homogeneous deformation during loading.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第2期219-225,共7页
Acta Metallurgica Sinica
基金
美国自然科学基金项目DMR-0520651,CMMI-0758535和MSS090046资助~~
