Autonomous filling of creep cavities in Fe-Au alloys studied by synchrotron X-ray nano-tomography

Journal article (2016)

Authors

H. Fang RST/Fundamental Aspects of Materials and Energy - AS , Novel Aerospace Materials - Aerospace Engineering
C.D. Versteylen RST/Fundamental Aspects of Materials and Energy - AS
S. Zhang RST/Fundamental Aspects of Materials and Energy - AS
Y. Yang European Synchrotron Radiation Facility (ESRF)
P. Cloetens European Synchrotron Radiation Facility (ESRF)
D.J.M. Ngan-Tillard Geo-engineering - CEG
E.H. Brück RST/Fundamental Aspects of Materials and Energy - AS
S. van der Zwaag Novel Aerospace Materials - Aerospace Engineering
N.H. van Dijk RST/Fundamental Aspects of Materials and Energy - AS
Research Group
RST/Fundamental Aspects of Materials and Energy (AS) (TU Delft)
Creep Synchrotron radiation Self healing X-ray tomography Fe alloys
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Published Date

01-12-2016

Language

English

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Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Fundamental Aspects of Materials and Energy

Abstract

The autonomous filling of creep-loading induced grain-boundary cavities by gold-rich precipitates at a temperature of 550 °C has been studied as a function of the applied load for Fe-Au alloys using synchrotron X-ray nano-tomography. The alloy serves as a model alloy for future self-healing creep resistant steels. The size, shape and spatial distribution of cavities and precipitates are analyzed quantitatively in 3D at a nanometer resolution scale. The filling ratios for individual cavities are determined and thus a map of the filling ratio evolution is obtained. It is found that the gold-rich precipitates only form at cavity surfaces and thereby repair the creep cavity. The shape of the cavities changes from equiaxed to planar crack like morphologies as the cavities grow. The time evolution of the filling ratio is explained by a simple model considering isolated cavities as well as linked cavities. The model predictions are in good agreement with the measurements.