Mixed-mode fracture characteristics of a laminated metal matrix composite

In this study, the fracture behavior of a laminated composite, composed of layers of metal matrix composite having 20 vol% particulate SiC and 2014-aluminum matrix and 6061-aluminum as the ductile layers, was investigated under mixed-mode (mode-I and mode-II) loading. The results indicate that the increase in the fracture toughness of the metal matrix composite due to lamination with more ductile 6061-aluminum under pure mode-I loading condition diminishes significantly with increasing load-mixity. The interfacial behavior of the layers is shown to be the reason for this reduction in the fracture toughness values. The predicted growth directions of the cracks during the fast fracture agree reasonable well with experimental observations, in spite of the laminated microstructure of the composite.