Effet de la pr'esence d'entailles sur la vie en fatigue de l'alliage de titane titane - 4-aluminium - 4-vanadium.

摘要

Ti-6Al-4V is the titanium alloy the most used in the industry, occupying more than half of the titanium market. Its mechanical properties and low density make this alloy particularly attractive for use in the aeronautical field. Even though it can be found in many rotating components of gas turbines, its fatigue properties are still relatively scarce in the open literature, and information on the notch effect on the fatigue life seems to be lacking.;This work has been carried out in collaboration with a major gas turbines manufacturer. The main objective is to get a better understanding of the notch effect on the fatigue life of the Ti-6Al-4V alloy. Ten different types of notched specimens, having a stress concentration factor K;For the types of specimens studied, the results have shown that the stress amplitude and the stress gradient at the root of the notch control the fatigue life. The portion of the total life required to initiate a 0.5 mm crack was found to vary between 75% and 95% depending on the type of specimen monitored. The notch sensibility ratio q, relating K