Atomistic and Experimental Investigation of the Effect of Depth of Cut on Diamond Cutting of Cerium.

Junjie Zhang,Tao Sun,Maobing Shuai,Ming Jin,Yao Li,Haibing Zheng

doi:10.3390/mi9010026

Abstract

The ultra-precision diamond cutting process exhibits strong size effects due to the ultra-small depth of cut that is comparable with the cutting edge radius. In the present work, we elucidate the underlying machining mechanisms of single crystal cerium under diamond cutting by means of molecular dynamics simulations, with an emphasis on the evaluation of the effect of depth of cut on the cutting process by using different depths of cut. Diamond cutting experiments of cerium with different depths of cut are also conducted. In particular for the smallest depth of cut of 0.2 nm, shallow cutting simulations varying the sharpness of the cutting edge demonstrate that an atomically sharp cutting edge leads to a smaller machining force and better machined surface quality than a blunt one. Simulation results indicate that dislocation slip is the dominant deformation mechanism of cerium under diamond cutting with each depth of cut. Furthermore, the analysis of the defect zone based on atomic radial distribution functions demonstrates that there are trivial phase transformations from γ-Ce to δ-Ce occurred in both the machined surface and the formed chip. It is found that there is a transition of material removal mode from plowing to cutting with the increase of the depth of cut, which is also consistent with the diamond cutting experiments of cerium with different depths of cut.

Highlights

IntroductionAn ultra-smooth surface is of significant importance for achieving high performance of parts and components that are used in fields such as precision instruments, aerospace and nuclear energy, etc
An ultra-smooth surface is of significant importance for achieving high performance of parts and components that are used in fields such as precision instruments, aerospace and nuclear energy, etc.For instance, surface roughness has a significant impact on both the corrosion and oxidation resistances of metallic surfaces, which subsequently influence functionalities and life cycles of metal parts and components [1,2,3]
We explore the dependence of machining mechanisms on depth of cut (DOC) by performing both molecular dynamics (MD) simulations and experiments of diamond cutting of cerium with different DOCs

Summary

Introduction

An ultra-smooth surface is of significant importance for achieving high performance of parts and components that are used in fields such as precision instruments, aerospace and nuclear energy, etc. Surface roughness has a significant impact on both the corrosion and oxidation resistances of metallic surfaces, which subsequently influence functionalities and life cycles of metal parts and components [1,2,3]. In particular for cerium, which is one of the most active lanthanide elements with high chemical activity, an ultra-smooth surface with nanometer surface roughness is greatly desired to improve its oxidation resistance. To facilitate the improvement of machined surface quality, a thorough understanding of machining mechanisms involved in the diamond cutting process is critical. In line with experimental study, theoretical investigation based on the molecular dynamics (MD) simulation has been widely conducted to explore the ongoing diamond cutting process

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Conclusion