High-cycle fatigue performance of solution-treated metastable-β titanium alloys

Autor: M Long, H.J Rack, Roy E. Crooks
Rok vydání: 1999
Předmět:
Zdroj: Acta Materialia. 47:661-669
ISSN: 1359-6454
DOI: 10.1016/s1359-6454(98)00343-7
Popis: The effect of grain boundary misorientation on the high-cycle fatigue performance of solution-treated, metastable- β titanium alloys was investigated. Initial damage during cyclic deformation was associated with the formation of coarse, planar slip bands, these often propagating through several grains without obstruction or redirection when intersecting with a grain boundary. This “continuous” slip through several grains was associated with the presence of a significant number of “low-angle” grain boundaries. Fatigue crack initiation was associated with crack initiation at intersecting planar slip bands at the free surface. The increase in operative slip length occasioned by the presence of low-angle grain boundaries lead to enhanced crack initiation and reduced lifetime. Fatigue crack propagation was characterized by step-like features formed through the interaction of the propagating crack and the coarse slip bands present in the plastic zone ahead of the crack tip. The direction of local fatigue crack propagation was also minimally affected when crossing low-angle grain boundaries.
Databáze: OpenAIRE