Enhanced adiabatic shear band susceptibility in Ti composites reinforced with quasi-continuous network of graphene nanosheets

Graphene nanosheets (GNSs) can remarkably advance the mechanical properties of titanium metal matrix composites (TiMCs) by forming a quasi-continuous network architecture. However, the failure mechanism of the network architecture, especially under impact loading, has never been truly understood. In this work, a Ti–6Al–4V based composite reinforced with GNSs was adopted to study the failure behavior of the quasi-continuous network architecture of GNSs under impact loading, as well as its influence on macroscopic behavior of TiMCs. Experimental results revealed that, the quasi-continuous networked TiMCs exhibited a propensity of failure by adiabatic shearing, where the shear band seemed to propagate (and probably also initiate) along the network architecture. Microstructural observation suggested that, instead of grain size or texture, the enhanced ASB susceptibility of the composite is attributed to the high defect density induced by networked reinforcement. Then, a comprehensive discussion relates the enhanced ASB susceptibility quantitatively with adiabatic shear dissipation energy.