Self healing of creep damage in iron-based alloys by supersaturated tungsten
H. Fang (TU Delft - RST/Fundamental Aspects of Materials and Energy, TU Delft - Novel Aerospace Materials)
N. Szymanski (Student TU Delft)
C.D. Versteylen (TU Delft - RST/Fundamental Aspects of Materials and Energy)
P. Cloetens (European Synchrotron Radiation Facility)
C. Kwakernaak (TU Delft - (OLD) MSE-1)
Wim Sloof (TU Delft - (OLD) MSE-1)
F.D. Tichelaar (TU Delft - QN/Afdelingsbureau, Kavli institute of nanoscience Delft)
S. Balachandran (Max-Planck-Institut für Eisenforschung)
Michael Herbig (Max-Planck-Institut für Eisenforschung)
E. Brück (TU Delft - RST/Fundamental Aspects of Materials and Energy)
S. van der Zwaag (TU Delft - Novel Aerospace Materials, Tsinghua University)
Niels Dijk (TU Delft - RST/Fundamental Aspects of Materials and Energy)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
When metals are mechanically loaded at elevated temperatures for extended periods of time, creep damage will occur in the form of cavities at grain boundaries. In the present experiments it is demonstrated that in binary iron-tungsten alloys creep damage can be self healed by selective precipitation of a W-rich phase inside these cavities. Using synchrotron X-ray nano-tomography the simultaneous evolution of creep cavitation and precipitation is visualized in 3D images with a resolution down to 30 nm. The degree of filling by precipitation is analysed for a large collection of individual creep cavities. Two clearly different types of behaviour are observed for isolated and linked cavities, where the isolated cavities can be filled completely, while the linked cavities continue to grow. The demonstrated self-healing potential of tungsten in iron-based metal alloys provides a new perspective on the role of W in high-temperature creep-resistant steels.