Microstructural Characteristics of Accumulative Roll Bonded Ni-Al Based Metal Intermetallic Laminate Composite

Abstract

The present investigation is an attempt to develop metal-intermetallic laminate composites based on Ni-Al system. In this study, Ni and Al foils (460 and 90 μm respectively) have been used for the development of Ni-Al laminate using accumulative roll bonding technique at 773 K. The laminate composites were then subjected to controlled annealing at 773 K, 823 K and 873 K for 1, 2 and 4 h to affect reaction at the Ni/Al interface leading to intermetallic compound formation. The accumulative roll bonded laminates showed good bonding of layers. Annealing treatment at 773 K led to slow formation of reaction product but maintained the interface integrity. Annealing at 873 K led to de-lamination of individual layers prior to the completion of reaction. A qualitative compositional analysis at the interfaces reflected the formation of Al-Ni copmpounds, and also a gradual compositional gradient across the interface. This process seems to be of promise so far as the continuous production of large scale metal-intermetallic laminate composites are concerned. A further study is underway to circumvent the delamination problems and property evaluation.