Fine-tuning of mechanical properties of additively manufactured AlSi10Mg alloys by controlling the microstructural heterogeneity

Cell structures decorated with Si precipitates are key microstructures that endow AlSi10Mg alloys produced by laser powder bed fusion (LPBF) with excellent mechanical properties. This study investigated the effect of heat treatment on the cell structure and properties of LPBFed AlSi10Mg alloys. Heat-treatment was performed within the temperature range of 270-320 degrees C, which did not alter the crystallographic texture and grain structure of the alloys. When the heat-treatment temperature increased, the strain-hardening ability of the alloys decreased through a weakening of the cell structure, leading to a decrease in the strength and uniform elongation of the alloy. Contrarily, when the annealing temperature exceeded 300 degrees C, the spatial heterogeneity of the cell structure decreased, significantly improving post-elongation by delaying the melt pool boundary decohesion of the alloys. This demonstrated that the positive and negative effects of the cell characteristics competitively affect the mechanical properties of the alloys, and the strength and ductility of the alloys are governed by the spatial heterogeneity of the cell structure. This study offers guidelines for fine-tuning the performance by optimizing cell characteristics of LPBFed AlSi10Mg parts. (c) 2023 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).