The effect of machine stiffness on grinding of silicon nitride

This study investigates the effect of machine stiffness on normal forces, a ctual depth of cut, and workpiece strength in grinding of silicon nitride. To obtain a grinding system with an adjustable stiffness, a compliant workh older is added to a precision grinder. Single-pass and multi-pass grinding experiments are conducted to evaluate the effect of machine stiffness. Cup- type diamond wheels of two different bond types and three grit sizes are us ed in the grinding experiments. Static and dynamic simulation is carried ou t to correlate grinding forces and actual depth of cut with machine stiffne ss. Since the simulation uses a time-domain model, it can accommodate non-l inearities caused by the effect of machine stiffness on grinding forces and actual wheel depth of cut, workpiece regeneration, wheel wear, as well as wheel bond type and grit size effects, etc. Particularly, the model allows simulating grinding instability and the interference phenomenon due to resi dual material removal in multi-pass grinding. The study concludes that both simulation and experimental results have a good agreement. (C) 1999 Elsevi er Science Ltd. All rights reserved.