Molecular dynamics characterization of diamond tool probe and workpiece contact for FS-FTS based on-machine surface form measurement

Abstract

A force sensor integrated fast tool servo (FS-FTS) has been developed by the authors for precision fabrication and on-machine surface form measurement of micro-structured surfaces, in which the on-machine surface form measurement is realized by using the diamond tool tip as a force controlled probe tip. In this paper, molecular dynamics (MD) simulations are carried out for characterizing the contact between the diamond tool tip and the workpiece surface with a contact depth at the subnanometric range. The subnanometric elastic-plastic transition contact depth, at which the plastic deformation in the workpiece is initiated, is identified based on the MD simulation. It is found that the tool edge geometry is an important factor to influence the elastic-plastic transition contact depth. The simulation results provide benefits for optimizing the design of the next generation FS-FTS, in which the tool-workpiece contact is desired to be controlled at the elastic deformation range so that there would be no damage to the workpiece during the FS-FTS based on-machine surface form measurement process.