Surface Roughness and Edge Roundness in Robotic-Assisted Abrasive Finishing of Metal Additive Manufactured Al-Si10-Mg Alloy

Abstract

Metal Additive Manufacturing (AM) components often exhibit poor as-built surface integrity, characterized by high roughness, surface defects, and tensile residual stresses, which can significantly affect their functional performance and lifespan. This study investigates the influence of a Robot-Assisted Abrasive Finishing (RAF) system on the surface roughness and edge roundness of Al-10Si-Mg parts fabricated by Laser Powder Bed Fusion (LPBF). The RAF system is based on the tribofinishing and enables the adaptive control of key process parameters, including abrasive media material and geometry, relative motion between the part and the media, and metalworking fluid. Surface roughness parameters (Sa, Sz, Sq) were measured using 3D Coherent Scanning Interferometry, which also allowed monitoring of edge radius evolution during polishing to assess the system’s capability to preserve geometrical features. Although parts finished using the hybrid mode that combines drag and vibratory finishing kinematics exhibit surface asperities and processing times comparable to those obtained with drag finishing alone, this approach produces sharper workpiece edges than drag finishing by itself. In contrast, vibratory finishing requires a longer processing time than both drag finishing and the hybrid process, but it is more effective in preserving edge roundness.