Year: 2003
Type: article
Abstract: The effects of small defects on the fatigue strength of Ti-6 Al-4V were investigated in tension-compression fatigue tests.TD simulate the defects, holes having 50, 200, 400, 760 and 1000μm diameters were introduced onto the surface of a series of specimens (Series A).Another series of specimens (Series B) were prepared to investigate the effect of a burr or a pre-crack which was introduced at the edge of the artificial hole.For Series A specimens, the fatigue limit was defined as the threshold for crack initiation from the edge of the hole.For Series B specimens, the fatigue limit was defined as the threshold for crack propagation from the burr or the tip of the pre-crackThe results of the fatigue tests for R=-1 indicated that the fatigue limits of Series B specimens were 20-60MPa lower than those of Series A specimens.In contrast to steels, non-propagating cracks did not form at the holes, a fact associated with the relatively high stress level for crack initiation from hole in Ti-6 Al-4V.It was also found that the √asea parameter model underestimated the fatigue limit of Series A specimens, but the model accurately predicted the fatigue limit defined by crack-growth threshold for Series B specimens.In addition it was noted that the presence of abun resulted in a decrease in fatigue life, since the bun facilitated the crack initiation process.
Institutions: Kyushu University, Pusan National University
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2019547749