Fretting Behavior of Additively Manufactured Ti-6Al-4V: A Fretting Map Based Framework

Additively manufactured Ti-6Al-4V, fabricated by selective laser melting (SLM), was experimentally investigated under fretting conditions. Fretting tests were conducted by using a bridge-type configuration in accordance with ASTM E2789 on two specimens subjected to different normal loads. Damaged surfaces were examined by optical microscopy and scanning electron microscopy (SEM) and the observations were synthesized in the load-slip amplitude space to develop the fretting maps. Boundaries on these maps delineate contact regimes (stick/partial slip and gross slip) and identify crack prone regions. The results show that increasing slip amplitude shifted the response from fatigue prone regime to wear dominated behavior, consistent with oxide debris interlayer formation and surface smoothing that suppress crack nucleation. The resulting fretting maps provide a systematic basis for distinguishing fretting regimes and support the design and selection of surface engineering strategies appropriate to each regime.