Dislocation dynamics and fracture processes in two-phase titanium aluminide alloys

The fracture behaviour of two-phase titanium aluminides was characterized by fracture toughness tests performed on chevron-notched three point bending bars. The alloys investigated had compositions and microstructures which are currently being considered for engineering applications. The paper considers the effects of microstructure and crack tip plasticity on the crack growth resistance. The reliability of the materials was assessed by ranking toughness data in Weibull plots and considering the anisotropy of the crack resistance.