Precision optical components are now manufactured by CNC (computer numerica
lly controlled) grinding technology using diamond composite tools. Tooling
performance, and in particular consistency of performance, is an important
issue in this automation. A key measure of performance is the power/forces
required for material removal, often summarized in terms of the specific gr
inding energy or 'Preston's coefficient'. In this study measurements of gri
nding energy were used, along with optical profilometry measurements of too
l surface features, to quantitatively characterize the performance and deve
lopment of a bronze-bond composite diamond tool during grinding of three op
tical glasses with distinctly different grinding behavior. Evolution of gri
nding performance is strongly related to both the process conditions and th
e glass type. These effects can be understood in terms of changes in the re
lative rates of bond and abrasive wear and the consequent evolution of the
tool surface. In particular in certain cases the evolution of tool surfaces
can be adjusted toward a state of dynamic equilibrium ('selfsharpening') b
y adjusting process conditions. (C) 2000 Elsevier Science S.A. All rights r
eserved.