Zhang Junjie, Zheng Haibing, Shuai Maobing, Li Yao, Yang Yang, Sun Tao
Center for Precision Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang, 621908, China.
Nanoscale Res Lett. 2017 Dec;12(1):464. doi: 10.1186/s11671-017-2235-1. Epub 2017 Jul 25.
The coupling between structural phase transformations and dislocations induces challenges in understanding the deformation behavior of metallic cerium at the nanoscale. In the present work, we elucidate the underlying mechanism of cerium under ultra-precision diamond cutting by means of molecular dynamics modeling and simulations. The molecular dynamics model of diamond cutting of cerium is established by assigning empirical potentials to describe atomic interactions and evaluating properties of two face-centered cubic cerium phases. Subsequent molecular dynamics simulations reveal that dislocation slip dominates the plastic deformation of cerium under the cutting process. In addition, the analysis based on atomic radial distribution functions demonstrates that there are trivial phase transformations from the γ-Ce to the δ-Ce occurred in both machined surface and formed chip. Following investigations on machining parameter dependence reveal the optimal machining conditions for achieving high quality of machined surface of cerium.
结构相变与位错之间的耦合给理解金属铈在纳米尺度下的变形行为带来了挑战。在本工作中,我们通过分子动力学建模与模拟阐明了铈在超精密金刚石切削过程中的潜在机制。通过赋予经验势来描述原子间相互作用并评估两个面心立方铈相的性质,建立了铈的金刚石切削分子动力学模型。随后的分子动力学模拟表明,在切削过程中位错滑移主导了铈的塑性变形。此外,基于原子径向分布函数的分析表明,在加工表面和切屑中均发生了从γ-Ce到δ-Ce的微量相变。对加工参数依赖性的后续研究揭示了实现高质量铈加工表面的最佳加工条件。