FORMATION OF NI5AL3 IN NI-AL LAMINATED STRUCTURES AND POWDER BLENDS

In this work, reactive formation of Ni5Al3 phase at 650 and 675 degree s C in Ni-Al laminated foil structures and consolidated powder blends is reported. The growth of Ni5Al3 has never been previously observed i n diffusion experiments; moreover. its formation was believed impossib le due to the very high nucleation barrier. Here, the absence of Ni5Al 3 in the earlier studied Ni-Al diffusion couples is discussed in terms of kinetic instability. (C) 1998 Elsevier Science B.V.