Effect of Ce addition on microstructure of Al20Cu2Mn3 twin phase in an Al–Cu–Mn casting alloy

Effects of Ce addition on microstructure of Al20Cu2Mn3 twin phase and mechanical properties of an Al–Cu–Mn casting alloy were investigated by transmission electron microscopy, selected area electron diffraction, high resolution transmission electron microscopy and tensile test. The results show that rare earth element Ce can retard the formation of the Al20Cu2Mn3 phase in the Al–Cu–Mn alloy. Compared with the Ce containing alloy, patterns of particles of the Al20Cu2Mn3 phase in the Al–Cu–Mn free Ce alloy are more diverse. The symmetry of neighboring components of twins is characterized by glide reflection and reflection. In addition, twins of the Al20Cu2Mn3 phase can enhance the mechanical properties of the Al–Cu–Mn alloy.