Measurement of optical surfaces generated by diamond turning

Abstract

For the manufacture of ultraprecision parts an entirely controlled machining technology is required as well as the capability of a complete evaluation regarding microgeometry and integrity of the generated surfaces. Optical and stylus profilometry are the commonly used technologies for determining surface roughness. Furthermore, atomic force microscopy AFM is frequently applied for 3D characterization of the microtopography. In this paper the application of atomic force microscopy in the field of diamond turning is presented by means of measuring and manufacturing examples. Typical applications are the manufacture of metal mirrors from aluminum, copper and electroless nickel substrates by diamond turning and fly-cutting operations using monocrystalline diamond tools. The atomic force microscope is used for the evaluation of the microtopography of these mirrors, which is decisive for their optical properties and quality. Additionally, the atomic force microscope can be used for measurements of microstructured components and the diamond tools itself. In this case, AFM is not only used for roughness measurement, but also for inspection and verification of the actual, respectively, the produced geometry of the components and the tools. The examples given in this paper illustrate the great potentials of atomic force microscopy in the field of ultraprecision machining.