Influence of Annealing Time on Microstructure and Mechanical Properties of Al-14.5Si Alloy Prepared by Super-Gravity Solidification and Cold-Rolling

In this paper, super-gravity solidification and cold-rolling were utilized to obtain Al-14.5Si alloys. The influence of annealing time on microstructure and mechanical properties of Al-14.5Si alloys was investigated. Our results indicated that high elongation was achieved by super-gravity solidification due to the submicron eutectic Si, making it possible to undertake the conventional cold-rolling. The yield strength (similar to 214 +/- 11 MPa) was significantly enhanced (similar to 68.5%) after cold-rolling mainly due to high dislocation density. The coarsening of eutectic Si could be observed during annealing, which resulted in a decrease in yield strength. The elimination of internal stress and lattice distortion during annealing led to a decrease in micro-cracks/voids beneath the fracture surface during tensile testing, which in turn enhanced the elongation.

Automated summary

In this study, Al-14.5Si alloys were obtained through super-gravity solidification and cold-rolling, and the influence of annealing time on the microstructure and mechanical properties of the alloys was investigated. The results showed that the presence of submicron eutectic Si in the alloys obtained by super-gravity solidification enabled the conventional cold-rolling, resulting in high elongation. After cold-rolling, the yield strength of the alloys was significantly enhanced due to the high dislocation density. The coarsening of eutectic Si during annealing decreased the yield strength, while the elimination of internal stress and lattice distortion during annealing enhanced the elongation.