3-D Surface roughness profile of 316-stainless steel using vertical scanning interferometry with a superluminescent diode

Abstract

Surface roughness is one of many parameters that influences on mass stability of standard weight, commonly used as a transfer standard of mass SI unit. One of the most famous non-invasive methods for determining surface roughness from a surface profile of material is a vertical scanning interferometry (VSI) with a white light source. In this research, 3-D surface profiles of 316-stainless steel, usually used as a material for standard weights, are constructed by using VSI, based on Michelson interferometer (MI). Because of its low-coherent properties, low cost, and compact light source, a superluminescent diode (SLD) is chosen as a low-coherence light source in our interferometry system. Since a continuous wavelet transform (CWT) algorithm provides accuracy results, it is also used as a numerical analyzing method for the interferogram signals, taking from our VSI. The surface roughness and measurement uncertainty, calculated from the constructed 3-D surface roughness profiles of 316-stainless steel samples, are discussed.