Self healing of creep-induced damage in Fe-3Au-4W by multiple healing agents studied by synchrotron X-ray nano-tomography

Y. Fu*, H. Fang, F. Monaco, P. Cloetens, F. D. Tichelaar, J. G. van Meel, E. Brück, S. van der Zwaag, N. H. van Dijk

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)
53 Downloads (Pure)

Abstract

Constant stress creep experiments at 550 °C were performed on a high-purity Fe-3Au-4W (wt.%) ternary alloy with about 1 at.% supersaturation for Au and W in order to study self healing of grain-boundary cavities by both Au-rich and W-rich precipitates. Using synchrotron X-ray nano-tomography, the development of the creep cavities and the healing precipitates at different stages of creep was visualised using two spatial resolutions (30 and 100 nm voxel size) for separate samples taken after different loading times. The healing kinetics was found to strongly depend on the nucleation time of the cavities. Cavities nucleated at an early stage of creep could be fully healed, while the healing of the late-nucleated cavities is much slower due to a decrease in the diffusional flux of the healing supersaturated solutes over time, as a result of (i) a decrease in inter-cavity spacing caused by cavity nucleation and (ii) a gradual depletion of the supersaturated solutes near the grain boundaries. The interaction between the competing healing mechanisms for creep cavities by Au-rich and W-rich precipitates is discussed. It was found that Au-rich precipitates are formed much faster than the W-rich precipitates, and thereby effectively provide creep damage healing on different time scales.

Original languageEnglish
Article number118266
Number of pages16
JournalActa Materialia
Volume239
DOIs
Publication statusPublished - 2022

Keywords

  • Creep damage
  • Self-healing
  • Ternary alloys
  • Tomography
  • X-ray synchrotron radiation

Fingerprint

Dive into the research topics of 'Self healing of creep-induced damage in Fe-3Au-4W by multiple healing agents studied by synchrotron X-ray nano-tomography'. Together they form a unique fingerprint.

Cite this