Effects of micro-alloying with Sc and Mn on microstructure and mechanical properties of Al-Mg based alloys

1INTRODUCTIONAluminum alloys containing scandium havemany excellent properties,such as high strengthtogether with high ductility,good neutron-irradia-tion and corrosion-resistance,and superior weld-ability[14],thus can serve as high-performancestructural materials.They are mainly used formanufacturing aerospace,defense and militaryfacilities.However,a critical Sc content must bereachedin the alloys in order to obtain a good per-formance[57],suggesting that a relatively largequantity of Sc…

Effects of micro-alloying with Sc and Mn on microstructure and mechanical properties of Al-Mg based alloys

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.