Phase transformation and subsurface damage formation in the ultrafine machining process of a diamond substrate through atomistic simulation

Abstract

This report explores the effects of machining depth, velocity, temperature, multi-machining, and grain size on the tribological properties of a diamond substrate. The results show that the appearance of graphite atoms can assist the machining process as it reduces the force. Moreover, the number of graphite atoms relies on the machining speed and substrate temperature improvement caused by the friction force. Besides, machining in a machined surface for multi-time is affected by its rough, amorphous, and deformed surface. Therefore, machining in the vertical direction for multi-time leads to a higher rate of deformation but a reduction in the rate of graphite atoms generation. Increasing the grain size could produce a larger graphite cluster, a higher elastic recovery rate, and a higher temperature but a lower force and pile-up height. Because the existence of the grain boundaries hinders the force transformation process, and the reduction in the grain size can soften the diamond substrate material.

Exploring the evolution mechanisms of indentation and scratching on diamond structural transformation based on molecular dynamics

“…It can be seen that when the depth changes from 7 Å to 10 Å, the increase in detached atoms is much greater than the previous three lower depths. These microscopic wear amounts can realize the transition from macro to micro in friction and wear experiments and can more intuitively investigate the micro-structure evolution of friction and wear [70].…”

“…The shear strain increases with the increase in temperature and has a cumulative effect, and the strain accumulation will accelerate diamond wear. According to relevant literature research [73,74], the increase of shear strain is attributed to the increase of friction heat during the friction process, which makes the temperature of the friction surface higher than the set temperature, and the carbon atoms and SiC ball at the friction interface will continue to react.…”

Machining mechanism of polycrystalline nickel-based alloy under ultrasonic elliptical vibration-assisted cutting

“…Recently, the molecular dynamics (MD) simulation has been employed to investigate the machining and deformation mechanism of nano cutting process [33][34][35]. It provides a good insight into material behavior during the nanoscale cutting process, which is difficult to be observed experimentally.…”

The Dislocation- and Cracking-Mediated Deformation of Single Asperity GaAs during Plowing Using Molecular Dynamics Simulation

“…At the same time, the microscopic mechanisms of crack emergence and propagation in GaAs are not entirely understood and the contribution of the crack to deformation behavior is not yet clear. Additionally, studies of GaAs in plowing simulations have shown that the deformation process is always accompanied by the formation of dislocations, stacking faults and phase transformation [21,22]. The mechanical deformation response of GaAs to contact damage has attracted extensive attention [23].…”