Fatigue Crack Propagation in Titanium Alloys.
Annual rept. 1 Jul 75-30 Jun 76,
CONNECTICUT UNIV STORRS DEPT OF METALLURGY
Pagination or Media Count:
This research has involved studies of fatigue crack initiation as well as fatigue crack propagation. Principal findings have been that subsurface fatigue cracks can be initiated in forgings of this titanium alloy when the alpha-phase size is of the order of 10 micron, a size which can be present in large forgings. This mode of fatigue crack initiation can have a deleterious effect on long-life fatigue performance at positive mean stress levels. Results of the fatigue crack propagation studies have shown that the rate of fatigue crack growth in air and in vacuum can be analyzed in terms of a modified continuum mechanics treatment of fatigue crack growth based upon the concept that the fatigue crack growth increment per cycle is related to the extent of crack opening displacement.
- Metallurgy and Metallography