摘要
采用蒙特卡罗方法和分子动力学方法相结合,模拟单晶硅微纳构件加工表面的时效过程,研究其对加工表面质量和构件力学性能的影响.模拟结果表明:在时效过程中,单晶硅微纳构件加工变质层的有序度显著提高,残余应力大幅降低,表面粗糙度略有增加,此外还发现加工变质层中非晶硅原子在时效过程中大幅减少,部分非晶硅出现了再结晶现象,其中部分BCT5-Si以及金属相(Si-II)结构原子转化为金刚石结构(Si-I).时效作用对加工后单晶硅微纳构件表面性能具有重要的影响,同时可以提高微纳构件的拉伸力学性能.
The machined workpiece has high mechanical storage energy because of the defect structures formed in nanocutting and their evolution from high energy state to the low energy state by adjusting atom positions automatically is called surface-energy aging. The effect of surface-energy aging on the surface properties of monocrystalline silicon workpiece is analyzed by Monte Carlo simulations of machined surface. It is shown that the surface-energy aging effect can increase the surface roughness and the degree of order of damaged layer, however reduce the residual stress and the average potential energy of workpiece. Amorphous silicon structure in metamorphic layer decreases and recrystallization phenomenon occurs in the surface-energy aging process. It is found that someβ-Si phase structures and BCT5-si phase structures transform into the diamond cubic structure of Si in the surface-energy aging process. Surface-energy aging effect has a great influence on the surface properties of the machined surface of monocrystalline silicon workpiece, and can improve the mechanical properties of micro/nanostructures.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第22期96-103,共8页
Acta Physica Sinica
基金
国家杰出青年基金(批准号:50925521)
国家自然科学基金(批准号:51075092)资助的课题~~
关键词
蒙特卡罗方法
纳米加工
表面性能
时变性
Monte Carlo simulation, nanomachining, surface properties, performance evolution
