Sustaining Cellular Structures in Additively Manufactured AlSi10Mg Alloy via Heat Treatments

The present study focuses on the development of heat treatments aimed at preserving the unique cellular structures obtained in selective laser melting (SLM) Al-10 wt.% Si-1 wt.% Mg (AlSi10Mg) alloy. Thermodynamic simulations, microstructural analyses, and mechanical property evaluations were conducted to elucidate the effects of traditional T6 heat treatment and low-temperature aging on the alloy's performance. The T6 heat treatment resulted in the decomposition of the fine cellular eutectic Si structure, leading to significant reduction in hardness, tensile strength and elongation. Thermodynamic simulations revealed the temperature-dependent phase evolutions in the alloy, guiding subsequent heat treatment strategies. Additionally, different low-temperature aging process was explored to preserve the cellular structure, promoting the precipitation of nanoscale needle- and rod-like precipitates in the alpha-Al base. This approach not only maintained tensile strength comparable to as-built specimens, but also increased hardness. The alloy exhibited combined maximum hardness and tensile properties by direct aging at 150 degrees C for 16 h. The study provides valuable insights into tailoring the mechanical properties of SLM-AlSi10Mg alloys through strategic heat treatment optimization by keeping nanosized cellular structures.Please confirm if the author names are presented accurately and in the correct sequence (given name, family name). Author 1 Given name: [Wondayehu Yeshewas] Family name [Alemu].Yes, the current name with Alemu as the family name is correct. Thanks for noting.