Effect of Sc Addition and Heat Treatment on the Fracture Behavior of Al-20%Mg2Si Composites: Experiments and Finite Element Simulations

• Published in: International journal of metalcasting Vol. 19; no. 4; pp. 2180 - 2198
• Main Authors: Xue, Zou, Shuyuan, Song, Tongyu, Liu, Dongyu, Bai
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.07.2025
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Metallic Materials; Structural Materials; Technical Paper; Sc; Al-Mg; finite element simulation; heat treatment; Si composites; modification
• ISSN: 1939-5981; 2163-3193
• DOI: 10.1007/s40962-024-01459-6

In this study, Al-20 wt% Mg 2 Si composites were prepared using an in situ endogenous process method. Various amounts of Sc were added to the composites, and a heat treatment process was employed to optimize the microstructures of the materials and enhance the overall properties of the composites. The study results indicate that the addition of Sc has a significant positive effect on both the microstructure and mechanical properties of Al-20 wt% Mg 2 Si composites. The inclusion of Sc leads to a more regular and uniformly distributed morphology of the primary Mg 2 Si phase, accompanied by a significant reduction in grain size. Particularly, when the Sc content is 0.3 wt%, the composite exhibits the most notable grain refinement effect, resulting in the best mechanical performance. The tensile strength reaches 152.7 MPa, the hardness measures 92.9 HV and the elongation is 2.82%. Through the heat treatment process, the morphology and distribution of the initial Mg 2 Si phase in the composites were optimized, resulting in significant improvements in both the morphology and distribution of the initial Mg 2 Si phase and the eutectic structure. Consequently, the tensile strength increased to 204.3 MPa, the hardness reached 117.8 HV, and the elongation improved to 3.72%. Finite element simulation was employed to model the tensile behavior of real microstructures of Al-20 wt% Mg 2 Si-0.3 wt% Sc composite in both as-cast and heat-treated conditions. The simulation results demonstrate good agreement with experiment. The fracture modes observed in both cases involve interfacial debonding and intergranular fracture. The simulation effectively showed the deformation process and stress distribution during tensile fracture. Moreover, the heat-treated model exhibits a higher load on the particles compared to the as-cast state. This finding provides evidence that the overall properties of Al-Mg 2 Si composites are enhanced following the heat treatment process.