Ultra-Precision Diamond Machined Freeform Optical Parts and Structures

Ultra-precision diamond machining (UPDM) is a key technology in the manufacture of high-quality parts with a surface roughness of a few nanometers and form accuracy in the sub-micrometer range. These high-quality parts have been widely applied in aerospace, optics, energy, electronics, mechanics, etc. The UPDM process generally uses a single-crystal diamond cutting tool, which possesses nanometric edge sharpness, form reproducibility, and wear resistance. This article elucidates three main types of UPDM: single-point diamond turning, ultra-precision fly cutting, and fast/slow tool servo diamond machining. Considering the significance of the machining accuracy for UPDM, the influencing factors, on-machine measurement methods, and error compensation methods are illustrated. The practical applications of UPDM are also exemplified and discussed.