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

摘要

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·m1/2 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.