An investigation of fracture behavior in layered NiAl/V composites

The possible use of vanadium microlaminates in the toughening of NiAl composites is examined in this paper. Ductile layer reinforcement has been shown to offer higher toughening of brittle intermetallics than ductile particles and fibers. Vanadium layers with thickness of 100, 200 and 400 {micro}m are shown to significantly improve the fracture toughness of NiAl. The extent of toughening, which increases with increasing layer thickness, is attributed to crack bridging and the interactions of propagating cracks with vanadium layers. Finite element models are used to explain the re-initiation of cracks in adjacent NiAl layers after retardation by the vanadium layers in the crack arrestor orientation.