Formation of intermetallic compounds with a high flux pulse molybdenum ion beam in steel and aluminium

Intermetallic compounds of molybdenum and tungsten implanted into H13 steel and aluminium were measured by transmission electron microscopy (TEM) and X-ray diffraction. Ions extracted from a metal vapour vacuum arc source with around 25-100 keV energy and a dose range (1-5)x1017 cm-2 were used for implantation. The ion fluxes were 25, 47, 68 and 320 μA cm-2. It was found from the results that the target temperature increases with increasing ion flux from 310degC (25μA cm-2) to 580degC (68 μA cm-2). Intermetallic compounds such as FeMo, Al2Mo, Al12Mo, Fe7W, Fe2W and Al5W were easily observed by TEM and X-ray diffraction when the flux was greater than 47 μA cm-2. In situ observation in a high voltage transmission electron microscope (HVEM) was used to investigate the structure and formation of intermetallic compounds of molybdenum-implanted H13 steel. The electron diffraction pattern of FeMo precipitates appeared at 500degC. Recrystallization and grain growth occurred at 650degC. (orig.)