Metallographic and Mechanical Research of the O-Ti2AlNb Alloy.

This paper provides the test results of the fatigue crack growth in notched specimens under tension. The tests were performed on plane specimens with external blunt two-sided notches at room temperature. The tested material was O-Ti2AlNb titanium alloy. The tests were carried out at constant load value and constant stress ratio R = 0. The tests were done at the fatigue stand Instron under the loading change frequency of 25 Hz. The results of mechanical and structural tests of the examined alloy were presented. Scanning electron microscopy (SEM) was used in metallography, which allowed for the initial identification of intermetallic phases. The development of fatigue cracks in the tested alloy indicates that there is a tendency for brittle fracturing, which ran along the grain boundary.