Investigation of microstructures in aluminium implanted with molybdenum ions

High-purity aluminum (99.999%) specimens were implanted with molybdenum ions. The resulting microstructures for both as-implanted and post-implantation-annealed specimens were analyzed. A supersaturated solid solution was retained in aluminum implanted with a maximum molybdenum concentration of 4.4 at. %. Annealing of the as-implanted solid solution initially produced Al12Mo with a predominantly lamellar morphology in the surface-modified region which, with further annealing at the same temperatures, transformed into a primarily interlocking lamellar morphology. The Al12Mo was identified using x-ray energy dispersive microanalysis (EDS) and convergent beam electron diffraction (CBED) techniques. A continuous Al12Mo film was isolated as the only second phase structure in the surface-modified region of aluminum annealed after implantation with molybdenum to a peak concentration of 11.4 at. %. The precipitate film was identified as Al12Mo using EDS and CBED. After annealing at 4000 C, the film in bulk specimens had a mottled appearance, while annealing at 5500 C resulted in a film with a granular structure