Dynamic shear fracture toughness and failure characteristics of Ti–6Al–4V alloy under high loading rates

A novel 2-bar/double-shear impact (2B/2SI) loading technique is used to study the dynamic mode II (shear) fracture characteristics of Ti–6Al–4V. The new specimen design, be in combination with a standard split Hopkinson pressure bar, circumvent classical limitations associated conventional one-point methods. This paper presents combined experimental-numerical approach determining toughness Ti–6Al–4V for broad range rates between 1.10 × 10−2- 4.98 107 (MPa, m1/2s−1). Results showed only slight initial increase toughness, which increases abruptly beyond 106 Fractographic examination distinctively different mechanisms operation at microscale, depending on rate loading. Failure through brittle-ductile, mixed-mode under quasi-static conditions; by contrast, surface exhibited fractographic features adiabatic shear bands (ASB) and material melting/re-solidification conditions. High-speed photography that both (DSF) ASB occurred during same process. Interactions DSF were observed influence dominant failure mechanism high rates.