On the relationship between quality index and fatigue life distributions in B201 and D357 alloy aerospace castings

Hüseyin Özedş, University of North Florida
Murat Tiryakioǧlu, University of North Florida


Tensile and fatigue testing results of premium quality B201 and D357 alloys reported in the literature have been reanalyzed by using Weibull statistics. When tensile data are used as a measure of the structural quality, which are converted into quality index, Qr, a distinct relationship has been observed between expected fatigue life and quality index. Moreover, probability of survival in fatigue life was found to be directly linked to the proportion of the elongation (quality index) distribution in a region where premature fracture is caused by old oxides and pores, providing further evidence about the relationship between elongation and fatigue performance.