Effects of water molecules on material removal behavior in Vibration Assisted Nano Impact-machining by Loose Abrasives - A molecular dynamics simulation study

Vibration Assisted Nano Impact-machining by Loose Abrasives (VANILA) is a novel nanomachining process that performs target specific nano abrasive machining of hard and brittle materials. An atomic force microscope (AFM) is used as a platform in this process wherein, nano abrasives, injected in slurry between the workpiece and the vibrating AFM probe, impact the workpiece and cause nanoscale material removal. Liquid medium is required in this process to confine the abrasives within the machining zone. However, the presence of liquid medium could significantly influence the abrasive dynamics as well as the substrate deformation behavior during the VANILA process. This study focuses on understanding the effect of liquid medium on the material removal behavior during the VANILA process. A Molecular Dynamics Simulation (MDS) based study is conducted under different initial conditions with and without the presence of liquid medium (water). The results obtained from the study showed that while the water absorbs some energy from the abrasive grain, it also provides a lubricating layer to the grain preventing adhesion on the workpiece surface. Visualizations of the atomic configurations of the workpiece showed that the presence of water molecules could significantly affect the material dislocations during the impact process.