Study on dynamic fracture behavior of TA15ELI alloy under mode-II loading by caustics method.

The dynamic fracture behavior of TA15ELI alloy with lath-like microstructure was studied by caustics method. Specimens with double-side pre-notch were tested under the plane-stress condition at mode-II loading with a drop hammer system. Caustics information recorded in films illustrated the histories of both crack length and stress intensity factor. The dynamic fracture toughness and crack growth velocity of TA15ELI with lath-like microstructure were determined to be 279 MPa·m^1/2 and 32.6 m/s, respectively. SEM fractograph analysis showed a mixed feature of mainly plastic mode for TA15ELI alloy in dynamic mode-II fracture. Shear localization was observed in the vicinity of the crack initiation area. [ABSTRACT FROM AUTHOR]