The Effect of Overload on Fatigue Crack Propagation in Metastable Beta Titanium-Vanadium Alloys

摘要

The crack retardation response due to single- and multiple-cycle overload of two titanium vanadium alloys (24 and 32 wt. pct. V) has been studied. It has been observed that the degree of retardation depends upon the vanadium content of the alloy, the load ratio, the number of overload cycles and the magnitude of the peak load. Fractographic observations show that the cracking mode may be changed in the overload affected zone from that in the preoverload region. These results seem to incidcate that the retardation behavior is mainly due to the compressive residual stresses arising as a consequence of the overload. The degree of retardation depends not only on the loading variables, but also on the material parameters like the monotonic and cyclic deformation behavior, and the stress-strain response. (Author)