Effect of abrasive flow machining (AFM) process parameters on surface roughness of AlSi10Mg parts produced with direct metal laser sintering (DMLS)

This study investigates the surface improvement of Direct Metal Laser Sintering (DMLS) produced AlSi10Mg alloy using Abrasive Flow Machining (AFM). Due to the layer by layer manufacturing mechanism, DMLS components typically exhibit high surface roughness, partially fused particles, and irregular surface features that may adversely affect service performance. A full factorial experimental design was conducted by varying abrasive grain size (240 and 400 mesh), abrasive concentration (40% and 60%), and cycle number. Surface roughness, material removal rate (MRR), macro scale morphology, and scanning electron microscopy (SEM) analyses were used to evaluate the effectiveness of the AFM process. The results showed that AFM significantly improved the surface quality under all investigated conditions, achieving roughness reductions exceeding 90% under optimum processing parameters. Cycle number was identified as the dominant factor governing both roughness evolution and material removal behavior. SEM observations revealed the progressive removal of melt pool related asperities, adhered particles, and manufacturing induced surface irregularities, resulting in a more homogeneous surface morphology. The optimum experimental condition was obtained at 400 mesh abrasive size, 60% abrasive concentration, and approximately 20 cycles. Statistical analyses confirmed the significance of the observed trends, while numerical optimization predicted an optimum condition close to the experimentally determined processing window. The findings demonstrate that AFM is an effective post processing technique for improving the surface quality of DMLS produced AlSi10Mg components and provide practical guidance for finishing additively manufactured metallic parts with complex geometries.