Multivariable model of the surface roughness of LPBF-manufactured AlSi10Mg alloy based on response surface methodology

This study presents an experimental and mathematical investigations of the effects of Laser Powder Bed Fusion (LPBF) process parameters on the surface roughness of AlSi10Mg alloy parts. A full-factorial experiment comprising 60 combinations of the main process parameters – laser power, scanning speed, and hatch spacing – was conducted. A third-order multivariable response surface model was developed from the measured roughness data to describe nonlinear relationships and interactions among the process parameters. The model accounted for approximately 86 % of the total variance in the experimental data and yielded mean prediction errors of approximately 0.9 µm for S_a and ± 0.2 µm for R_a. The minimum roughness values, S_a ≈ 5 µm  and R_a ≈ 2 µm, were obtained at a laser power of 400 W, a scanning speed of 938 mm/s, and a hatch spacing of 80 µm. Laser power, hatch spacing, and their interaction had the greatest effect on the resulting surface roughness. The developed model can be used to predict surface quality and select optimal process parameters for the LPBF manufacturing of aluminum alloy components.

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