METHOD FOR FORMING OF OPTICAL GLASS ELEMENT

摘要

A high quality optical glass elements is formed by hot pressing in mould coated with thin film of noble metal alloy. The press shaping mould comprises a cermet composed of tin, and a precious metal layer formed on it. The precious metal layer is made of alloy comprising 60-99 wt.% Pt and the remainder of at least one of elements selected form the group of Ir, Os, Pd, Rh and Ru. The cermet can be formed into a mould having almost the same accuracy as that of super hard alloy composed mainly of WC, and accuracy of the surface of the mould is finished easily up to the max. surface coarseness of 0.02 micron or less.