Potential Energy/Volume Evolution and Atomic Trajectories Analysis of Amorphous Alloys in Nanometric Cutting Process: A Molecular Dynamic Simulation Approach

Amorphous alloys are subjected to extreme deformation conditions during machining operation. Currently their deformation mechanism at micro-scale during cutting process is still unclear. Based on the changes of potential energy and volume for the cutting layer and the workpiece layer, the deformation behavior of amorphous in the nanometric cutting process was investigated using molecular dynamics simulation. In the cutting layer, various stages of the cutting were analyzed, and it is found that the potential energy of yielding is approximately equal to the value near the glass transition temperature in the cooling process, which supports the view that the yielding is a stress-induced glass transition phenomenon. Further, the free volume at yielding was also calculated (about 3.9%). In the workpiece layer, the potential energy slope of elastic recovery is larger than the system relaxation, which indicates that the effect of stress to amorphous is faster than the temperature. It is also observed that the slopes of potential energy and volume have a strong correlation with stress or strain rate. Finally, the deformation process was further investigated by studying single-atom trajectory.