Effet de la température de frittage et du vieillissement artificiel sur la microstructure et les propriétés mécaniques de l’alliage AlSi10Mg

Abstract

This project was initiated within the framework of the METALTec industrial research and development consortium, associated with the National Research Council Canada (NRC), in collaboration with the industrial partners AP&C and Dana Incorporated, with the objective of investigating the sinterability of aluminum alloys from an industrial application perspective. This thesis analyzes the evolution of phases as a function of sintering temperature, as well as the mechanical behavior of the AlSi10Mg alloy before and after artificial aging. Compacted AlSi10Mg powders were sintered under a nitrogen atmosphere at 571, 575, and 579 °C, using heating rates of 0.5 and 3 °C/min, with a 2 h holding time at the sintering temperature, followed by cooling at 5 °C/min. These conditions correspond to the thermal window ensuring maximum densification. At 571 °C, the microstructure is characterized by fine α-Al grains and uniformly distributed globular Si particles. At 575 °C, grain growth and Si coarsening are observed. At 579 °C, the excess liquid phase promotes significant α-Al grain coarsening, the formation of partially interconnected Si networks, and the elongation and coarsening of β-Al₅FeSi intermetallics. In the as-sintered condition, hardness shows an inverse correlation with α-Al grain size as well as with the size and distribution of Si particles. After artificial aging, hardness and ultimate tensile strength nearly doubled, while elongation at fracture decreased slightly, despite the absence of significant changes in α Al grain size and Si morphology. A partial transformation of Fe-rich phases toward the more thermodynamically stable γ-Al₃FeSi₂ phase was also observed.

Date	15 May 2026
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Vincent Demers (Supervisor) & Alena Kreitcberg (Co-supervisor)