Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics

Nanoscale Research Letters, Jan 2018

Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics simulation software Lammps was used to simulate the cutting of single crystal copper with SiC abrasive grains at different cutting angles (0o–45o). At a constant friction coefficient, we found a direct relation between cutting angle and cutting force, which ultimately increases the number of dislocation during abrasive flow machining. Our theoretical study reveal that a small cutting angle is beneficial for improving surface quality and reducing internal defects in the workpiece. However, there is no obvious relationship between cutting angle and friction coefficient.

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://link.springer.com/content/pdf/10.1186%2Fs11671-017-2412-2.pdf

Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics

Li et al. Nanoscale Research Letters Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics Junye Li 0 Wenqing Meng 0 Kun Dong 0 Xinming Zhang 0 Weihong Zhao 0 0 College of Mechanical and Electric Engineering, Changchun University of Science and Technology , Changchun 130022 , China Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics simulation software Lammps was used to simulate the cutting of single crystal copper with SiC abrasive grains at different cutting angles (0o-45o). At a constant friction coefficient, we found a direct relation between cutting angle and cutting force, which ultimately increases the number of dislocation during abrasive flow machining. Our theoretical study reveal that a small cutting angle is beneficial for improving surface quality and reducing internal defects in the workpiece. However, there is no obvious relationship between cutting angle and friction coefficient. Molecular dynamics; Nanometric cutting; Impacting direction; Monocrystalline copper Background In modern ultra-precision machining, material removal technologies play an important role in microelectronics, micromechanical, and optical element manufacturing. The demand of miniaturized devices with high dimensional accuracy and quality surface, making ultraprecision processes the major choice in the mentioned field [ 1 ]. Moreover, the changes of surface components and sub-surface structure are at the nanometer length scale. Abrasive particle flow polishing technology plays an important role in many fields of precision machining and is just like other non-traditional finishing technologies which improve surface quality. This technology has attracted lots of researchers due to its significant role. E. Uhlmann and other researchers have reported the computer simulation of abrasive grain polishing ceramic surface for the designed experiments to verify the grinding fluid flow of various processing factors on the effect of cutting materials [ 2 ]. Sehijpal Singh and other researchers use the abrasive flow polishing technology for cutting copper and aluminum materials. From scanning electron microscopic analysis, they found a deep groove surface of their workpiece [ 3 ]. G. Venkatesh and other researchers have reported ultrasonic assisted abrasive grain polishing technology for the conical gear on the complex surface of finishing process. In this technique, the abrasive grain velocity is higher than the conventional abrasive grain flow to collide with the surface of workpiece, which can improve the processing efficiency. From their experimental and theoretical methods, they found that this technology is one of the best choices for gear blade finishing [ 4, 5 ]. K. Kamal et al. studied the rheological properties of the abrasive liquid in the fluid abrasive viscosity, shear rate, and creep time [6]. However, most of the abrasive flow polishing studies are based on macro level and very rare attention has been paid to micro level. In the abrasive flow polishing process, the suspended particles in the medium will flow along the media, at a certain speed with the impact of micro cutting workpiece surface (Fig. 1). As the shape of the abrasive grains is not regular, having certain edges and corners which act on the surface of the workpiece, similar to the tool. But the cutting process is on the atomic scale which is obviously different from the material removal process. A nanoscale cutting involves few nanometers or less of the material surface, but it is very difficult to observe this process by experiments. Therefore, MD simulation as a theoretical investigation method is very useful in studying the nanometric cutting process. Molecular dynamics as a computer simulation technique, which uses a time-based statistical mechanics method to study the interrelation of atoms for conditions prediction and analysis. This is also a powerful tool for simulating and understanding materials removal processes. In the literature, there exist numerous studies regarding MD as a tool to investigate precision machining. Oluwajobi and Chen have done extensive work on MD simulation of nanoscale machining of copper [ 7 ]. In their studies, they investigated various parameters for nanomachining such as minimum cut depth, geometry, and interatomic potential [ 8 ]. In addition, MD simulations results have also been successful in the past to address number of problems concerning the nanometric cutting process of brittle materials such as silicon [ 9 ]. Komanduri et al. conducted an MD simulation for nanometric cutting of single-crystal of pure silic (...truncated)


This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1186%2Fs11671-017-2412-2.pdf

Junye Li, Wenqing Meng, Kun Dong, Xinming Zhang, Weihong Zhao. Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics, Nanoscale Research Letters, 2018, pp. 11, Volume 13, Issue 1, DOI: 10.1186/s11671-017-2412-2