INFLUENCE OF NICKEL ON REACTIVE SINTERING OF IRON-ALUMINUM INTERMETALLICS

Reactive sintering of rolled compacts consisting of elemental iron and aluminium powders has been studies. The results demonstrate that the addition of nickel can inhibit the swelling of sintered iron and alumi nium powder compacts and promote densification of the sintered samples . Reactive sintering of rolled compacts of the powder mixture is an ef ficient method of obtaining high final densities (>99% theoretical). R eactive sintering produces a two phase structure. It was found that wh ere pores exist, they are formed in the intermetallic Fe3Al compound p hase and that these pores largely disappear when nickel is added. Roll ing increases the contact surface area between the iron and aluminium powder particles, resulting in a reduction in pore size. The effect of nickel additions and rolling on the reactive sintering densification of the iron and aluminium powder mixture is discussed.