Molecular Dynamics Simulation of Nanometric Machining Under Realistic Cutting Conditions

Abstract

Molecular Dynamics (MD) simulations of nanometric machining of single-crystal copper were conducted at a conventional cutting speed (5m/s) and different depths of cut (0.724 – 2.172 nm). The simulations were carried out to predict cutting forces and investigate the mechanism of chip formation at the nano level. The effect of tool rake angles and depths of cut on the mechanism of chip formation were also investigated. Tools with different rake angles, namely 0°, 5°, 10°, 15°, 30°, and 45°, were used. It was found that the cutting force, thrust force, and the ratio of the thrust force to cutting force decrease with increasing rake angle. However, the ratio of the thrust force to the cutting force is found to be independent of the depth of cut.

The effect of interatomic potentials on the molecular dynamics simulation of nanometric machining

“…The ratio between the tangential, lateral and the normal components of the cutting forces is similar to that found in conventional machining for the Morse and the EAM potentials. The results of the EAM model are comparable with those in [25,26], where the EAM potential best describes the metallic bonding in the copper atoms. In contrast, the pair potentials (both LJ and Morse potentials), do not incorporate the many-body effects; they have no environmental dependence and they do not account for the directional nature of bonding in metals [29] .…”

“…They modelled two abrasives that cut through a workpiece of 100 000 atoms over its whole length at 100 m/s. Pei et al [25] and Promyoo et al [26] carried out MD simulations of the nanometric cutting of copper with diamond tool. They both studied the effects of the tool rake angle and the interatomic potentials (Morse and EAM) on the process.…”

Molecular Dynamics Simulation of Nanoscale Machining

“…(Oluwajobi & Chen, 2011a) From Figures 11 -13, it can be observed that the cutting forces variation is lowest for the EAM potential. The results of the EAM model are comparable with those of (Pei et al, 2006, Promyoo et al, 2008, and the EAM potential best describes the metallic bonding in the copper atoms. In contrast, the pair potentials (both LJ and Morse potentials), do not incorporate the many-body effects; they have no environmental dependence and they do not account for the directional nature of bonding in metals (Li et al, 2008).…”

“…2. Atomistic Interaction in Nanometric Machining (Ikawa et al, 1991, Promyoo et al, 2008 www.intechopen.com Figure 2 shows the time increment (Δt), in which every atom changes its position and interacts with its surrounding neighbour atoms in a manner that is determined from the interatomic potential function.…”

Molecular Dynamics Simulation of Nanometric Cutting

“…Figures 8 and 9 show the variations in cutting and thrust forces per unit width, respectively, at a cutting speed of 5 m/s. The results obtained at a cutting speed of 500 m/s (Promyoo, 2008) and from the study of Komanduri et al (1999) are also given.…”