Correlation of precipitation state in a nickel-base superalloy on fatigue damage:A local approach of crack initiation resulting from the localization of plastic deformation on slip band

The paper is concerned with the examination of the correlation of precipitate sizes on the damage characteristics of Waspaloy in favor to investigate more deeply the local conditions related to the localization of plastic deformation that govern the probability for a specific grain to be damaged. In particular, a local approach is implemented where undamaged grains and damaged grains are analyzed separately through statistical assessments of slip band properties. It is exhibited that the mean extrusion height of the damaged grains is functionally dependent on the precipitate size, while the one of undamaged grains remains constant. In addition, it is shown that the precipitate size does affect strongly the mechanism of crack nucleation and the morphology of slip band at the crack initiation phase. (C) 2012 Elsevier B.V. All rights reserved.