Experimental study on aspheric surface machining using elastic deformation moulding method

Abstract

A novel aspheric surface machining, elastic deformation moulding method is proposed. Based on the linear elasticity of brittle optical materials, the elastic deformation moulding method can convert complicate aspheric surface machining to simply flat surface machining. The basic principle of the new method is described, a concave parabolic mould made of micro-porous ceramic is designed and machined, and an elastic deformation moulding machining system based on vacuum absorption is built. A machining experiment is then carried out. After 45 min lapping and 90 min polishing, a parabolic surface with form accuracy less than P-V 1.8 μm (within the radius of 9 mm) and a smooth surface with roughness Ra 7 nm is obtained, and the reasons of the machining form error generation are analysed. Experimental results show that the proposed aspheric surface machining method can achieve high machining quality with high efficiency.