An optimal fuzzy decision-making approach for laser powder bed fusion of AlSi10Mg alloy

Abstract

Abstract The present work proposes a fuzzy decision-making approach for the optimisation of the Laser Powder Bed Fusion (L-PBF) processing of AlSi10Mg alloy. First, a systematic approach based on Design of Experiment was adopted in order to identify and explain the effect of each operational parameter, i.e. volumetric energy density and building orientation, on the response variables, i.e. ultimate tensile strength, hardness and roughness. Then, a combined fuzzy-multi-objective genetic algorithm model was developed and tested in order to find the best input parameters’ combination able to satisfy the requirement of the highest mechanical performances. The use of a multi-objective optimisation based on genetic algorithm concerned the computation of optimal fuzzy numbers in order to take into account a precise percentage of experimental data for a given degree of membership, in combination with the smallest uncertainty level. Moreover, from the technological point of view, the proposed experimental results showed a similar and even improved mechanical properties of the alloy, if compared with the die casted one, except for the roughness. Finally, the fuzzy process maps generated allow to select the operational parameters in order to obtain the desired process output, in combination with the lowest uncertainty level, providing, as additional information, how much the accuracy of the model and the process varies by changing those operational parameters.