Turning of optical glasses at room temperature

The feasibility of high speed diamond turning of optical glasses at room temperature without production of brittle chips has been studied for a wide variety of inorganic glasses. Transparent and nearly stress free new surfaces are propduced by microshearing of the glass in a viscoplastic manner due to adiabatic melting and instantly annealing at higher cutting speeds. It is shown that both plastic cutting speed and maximum usable feed rate are strongly dependent on glass type.