Abstract: Ni/Al composite was successfully prepared by ARB process in laboratory. Effects of accumulative rolling pass and heat treatment on the hardness of composite were studied. The results show that the hardness of Ni, Al component and composite increases with the increase of rolling passes. The deformation of Al is restrained by the integrity of the material due to the layered structure of Ni component when the rolling pass is less than 3, which leads to the abnormal increase of the overall hardness of the composite. When the rolling pass n>3, the inlay effect of Ni particles in the Al component weakens the inhibition of deformation of Al component, which slows down the increase of overall hardness of the composite. The relationship model of n with Ni, Al component and overall hardness of composite are established. After 250 ℃×50 min heat treatment, the recrystallization and decrease of additional stress result in the decrease of the hardness of Ni, Al and composite materials as a whole; the degree of recrystallization of Ni layer particles is uneven due to the uneven deformation, which makes the hardness of Ni component fluctuate greatly.

Key words: multilayered Ni/Al composites, accumulative roll bonding (ARB), hardness, cold work hardening, heat treatment softening