Optimization of Machining Parameters in Ultra-precision Diamond Turning of Zinc Selenide

Infrared lenses are becoming a vital part of medical and defense applications. Zinc Selenide material is preferable for such applications because of its low absorption of infrared wavelength and high transmissibility of visible light. However, zinc selenide is a brittle material, and therefore polishing and grinding processes are traditionally used to achieve high tolerances in zinc selenide material surface. In this research, a diamond turning machine is used for spherical machining of the Zinc Selenide material. Diamond tool having a negative rake angle and 1.5 mm nose radius are used. The machining parameters have been optimized for achieving a Nano-level surface roughness without grinding and polishing, for optical applications. The effect of the machining parameters on the surface quality of zinc selenide has also been studied.