FORMATION OF AN INTERMETALLIC PHASE BY HIGH-ENERGY IMPLANTATION - THECASE OF NICKEL IN ALUMINUM

Phase transformations induced by Ni implantation in Al at energies of 22, 27.7 and 40 MeV has been studied by transmission electron microsco py (TEM) and secondary ion mass spectroscopy. Various Ni doses corresp onding with peak concentration of 0.03, 3.5, 6.7 and 12.0 at % were im planted into polycrystalline Al at room temperature, and the specimens were annealed with different heat treatments. Amorphization and Al3Ni precipitates were observed. In this paper the process of amorphizatio n is discussed using both the thermal spike mechanism and the point de fects accumulation mechanism. It is concluded that the accumulation of defects is needed for amorphization to occur.