Comparison of different optical measurement methods in the evaluation of the wear of SLS-fabricated tool used for free abrasive machining
摘要
In precision machining, maintaining dimensional accuracy and consistent surface finish in the workpiece can be achieved with regular measurements of the tool’s flat surface. However, the methods used to measure and assess the condition of the tool’s flat surface have a significant impact on the quality of the machined output. This research paper demonstrates the measurement results of the wear of an additively fabricated abrasive tool after 840 min of one-sided lapping of the ceramic material Al2O3. The surface microscopic observation using a 3D optical profilometer revealed that the surface characteristics of the polyamide lapping tool were mainly influenced by the three-body abrasion. By employing a confocal measuring technique and minimum zone (MZ) method, 3D optical profilometer measurement results determined the contact, non-contact, and highest contact locations on the lapping segments radial axis. On the contrary, based on global surface observation using a 3D laser scanner, the profiles of the lapping segments were obtained by extracting cross-sectional entities along the segments radial axis. The two measuring techniques determined the same location of highest contact in the tool radial length. When comparing the waviness parameter of maximum height (Wt), measurement techniques resulted in a comparable topographic profile with a difference of less than 0.05 mm. However, the 3D optical profilometer is observed with great potential, as it offers more ways to evaluate the flat surface of lapping segments, whilst the 3D laser scanner is useful for quick measurements.