抄録
The analysis of factors controlling fretting fatigue life has been tried using a Ti-6Al-4V alloy under a number of environments. The failure mechanism of fretting fatigue was related to friction force and the environments.
At a contact pressure of 50 MPa in air and argon, "elastic slip" arose between the pad and the contacting surface and the main crack was initiated at the outer area of the contacting surface.
At a contact pressure of 50 MPa under liquid environments such as pure water, synthetic sea water, CH3OH, and LiCl-CH3OH, and at a contact pressure of 20 MPa in air, "macro slip" arose and the main crack was initiated at the middle area of the contacting surface. The fretting fatigue life in synthetic sea water or CH3OH from which the effect of friction force was eliminated was the same as that in air. The life in pure water, however, was longer and the life in LiCl-CH3OH was shorter, compared with the life in air. It seemed that the former was caused by the removal of micro carcks due to wear particles in fretting and the latter was caused by the stress concentration due to the adhesion of wear debris to the contacting surface.
