Effect of Mg on nucleation process of recrystallization in Al-Mg-Si/SiCp composite
(1. School of Materials science and Engineering, Central South University, Changsha 410083, China;
2. Advanced Research Centre, Central South University, Changsha 410083, China)
2. Advanced Research Centre, Central South University, Changsha 410083, China)
Abstract: The recrystallization nucleation processes of two cold-rolled Al-Mg-Si/SiCp composites with different contents of Mg are investigated mainly by dynamic mechanical analyzer (DMA) and electron microscopy including high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and high-resolution transmission electron microscopy (HRTEM). Internal friction and electron microscopy results show that solute atom clusters are present in association with dislocations in supersaturated cold-rolled composites. During recrystallization process, the internal friction peak position of Al-Mg-Si/3SiCp/2Mg (volume fraction, %) is higher than that of Al-Mg-Si/3SiCp (volume fraction, %) due to more solute atom clusters formed in association with the dislocations in the cold-rolled composite with a much higher Mg content, indicating a stronger resistance for the recrystallization nucleation.
Key words: aluminum matrix composites; recrystallization; internal friction; dislocation; microstructures；transmission electron microscopy;