Abstract
The relevance of three different techniques (Stylus Profiler (SP), Scanning White-Light Interferometry (SWLI) and Atomic Force Microscopy (AFM)) to characterise the topography of aluminium and hard steel surfaces, was investigated. Evolution of roughness parameters (Ra and Rt) was analysed according to the evaluation length. Asymptotic Ra values showed good agreement between data measured by SP and by AFM. SWLI data show important discrepancies with the other instruments due to their sensitivity to surface morphologies. AFM is the best instrument to detect micro-roughness but is limited by its maximum evaluation length. SP (2D measures) is, therefore, a good compromise to characterise surface morphologies over a wide spatial range.