Fatigue behaviour of notched PVD-coated titanium components

In this paper the fatigue behaviour of Ti-6A1-4V alloy coated with a TiN arc-deposited PVD film was studied. Rotating bending tests (R = -1) were carried out on standard "hourglass" specimens to evaluate the fatigue limit at 200000 load cycles. Conventional and notched (120° V-notch transversal to the rotating axis at the minimum cross section area) specimens were tested, both coated and uncoated, to investigate the effect of the coating on the fatigue limit of the titanium alloy, with and without the surface notch. Fracture surfaces were observed by SEM. The coating did not improve the titanium alloy fatigue life