Fatigue crack nucleation and growth mechanisms for Ti6Al4V in different environments

In this work fracture surfaces of Ti-6Al-4V flat samples subjected to fatigue tests were examined by means of a scanning electron microscope. SEM analyses allowed to observe in detail the morphology of the fracture surfaces, in order to identify the crack nucleation zones and the crack growth mechanisms accurately. The surface morphologies were examined in order to compare the alloy behavior, considering different test environments and stress concentration factor values (Kt). The analyses resulted in the observation of different corrosion fatigue micro-mechanisms related to the stress concentration factor and to the test environment.