Effects of micro-alloying with Sc and Mn on microstructure and mechanical properties of Al-Mg based alloys
(1. College of Mechanical Engineering, South China University of Technology,
Guangzhou 510640, China;
2. School of Materials Science and Engineering, Central South University,
Changsha 410083, China)
Guangzhou 510640, China;
2. School of Materials Science and Engineering, Central South University,
Changsha 410083, China)
Abstract: An extensive investigation was made on the effects of micro-alloying with small amounts of Sc and Mn on the microstructure and mechanical properties of the Al-Mg based alloys. It is found that the micro-alloying can significantly enhance the tensile strength of the alloys, and eliminate the dendritic cast structure in it. Many fine, spherical and dispersive Al3Sc particles are found in the annealed Al-Mg-Mn-Sc alloys, which can strongly pin up dislocations and subgrain boundaries, thus strongly retarding the recrystallization of the alloys. The strengthening of the micro-alloyed Al-Mg alloys is attributed to the precipitation strengthening by the Al3Sc particles and to the substructure strengthening.
Key words: Al-Mg alloy; Al-Mg-Mn-Sc alloy; Al3Sc particle; microstructure; mechanical properties; micro-alloying