Surface Texture Characterization by means of db4 wavelets

The objective of the paper is to show that wavelets may be used to analyse surfaces for determining the contributions of (1) roughness, (2) waviness and (3) form to the surface texture. The ability to separate the different contributions could be useful, for instance, when geometrical characteristics of waviness are to be analysed for evaluat-ing manufacturing performances. In those cases, roughness contribution to surface texture is a sort of noise. Matlab has been chosen as a suitable framework for developing this work, because (1) it has a specific toolbox for studies requiring use of wavelets, (2) a programming language is available for developing specific applications, and (3) it has facilities for developing user-tailored outputs. 11 components have been analysed, with materials ranging from Aluminium alloys to Fe 360, to PVC, brass, grey iron and high-alloyed steel. The relevant manufacturing processes are (i) sand casting, (ii) die casting, (iii) wire edm, (iv) forging, (v) milling, (vi) turning, and (vii) injection moulding.