Three wagons method to analyze ductile mode grinding processes

Abstract

Ductile mode machining is usually applied for the optical finishing operation of e.g. tungsten carbide molds to be used for precision glass molding. In this paper, we report on a process analysis of ductile mode machining analyzing the influences of critical process parameters on the level of surface roughness being generated for tungsten carbide. To that aim, a recently developed method for process optimization in optics fabrication, the three wagons method, was applied identifying critical process parameters determining the eventual level of surface roughness within the ductile process window of UPM machining. Based on the experimental data collected, a new formula was developed enabling the prediction of the level of surface roughness being generated by ductile machining. Applying this formula, an optimized set of critical process parameter values has been determined predicting a minimum level of surface roughness on tungsten carbide (CTN01L) by ductile mode material removal of about 1 nm rms which has been proven in experiment. The developed formula enables a better predictability of level of surface roughness within the process window of ductile mode machining.