PSI - Issue 53

Bruno Sousa et al. / Procedia Structural Integrity 53 (2024) 291–298

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Author name / Structural Integrity Procedia 00 (2023) 000–000

Fig. 4. Surface roughness measurements (after machining) of the various test samples and correspondent milling time: (a) perpendicular to feed direction; (b) parallel to feed direction).

Fig. 5. Signal-to-noise (SN) ratio plots obtained from Taguchi method for Ra (a), Rz (b) and milling time (s).

3.2. Polishing

Due to portraying the worst and best conditions in terms of time and surface quality, A1 and A3 machined samples were selected to be polished according to the sequential methodology explained in section 2.2. It can be observed that the Sa values tend to be somewhat the same for the polishing step, particularly for those that use the diamond pastes. However, in the case of the grinding steps (B1 and B2) it seems that the initial machined surface quality has some influence on the obtained surface roughness values. The surface roughness of the sample milled with the A3 parameters did not significantly change from B1 to B2, meaning this step could be skipped, which in turn may result