3550 Relationship between Fatigue Properties and Microstructures in Ti-xMo-3Al Alloys
Details
Rotating bending fatigue tests of three kinds of Ti alloy which have different crystal structure were carried out. The results obtained are as follows. (1) Fatigue limit of the Ti alloys decreased with an increase in Mo content. As a result, the fatigue limit of β Ti alloy(non-ageing) was the lowest. This originates from the difference of the critical stress of crack initiation. (2) It became clear that a crack initiate at the boundary of the lath martensite and the boundary of the β grain. In the case of α' and α" Ti alloy, the cracks extend perpendicular to the axis of stress. on the other hand the crack of the β Ti alloy propagated in the grain boundary.
