Micro-Cutting Mechanisms in Silicon Nitride Ceramics Silinit R Grinding

Abstract

The paper contains an experimental study of micro-cutting intended to help the optimization of the grinding process of the silicon nitride ceramic Silinit R (Si3N4 - Al2O3 - AIN - TiN). The investigations were carried out to determine the normal and tangential cutting forces, the critical penetration depth and the specific grinding energy as a function of the grain penetration speed and depth. The micro-cutting process was performed with a single diamond cone-shaped grain (tip angle 120 [degrees] and tip radius 0.2 [min]) at varying depths of cut. The critical grain penetration depth separating ductile flow from brittle fracturing falls within the 6-8 [mu m] range. The specific grinding energy ranges from 135 - 180 [J/mm(3)] in ductile flow and from 60 80 [J/mm(3)] in brittle fracturing.