Abstract
The mechanical properties of an ion-irradiated Ni-based superalloy have been evaluated using nano-indentation hardness tests. A high-energy Ni ion beam was employed for irradiation at room temperature up to different doses. Nano-indentation tests were carried out in the range of 100–1000 nm to measure hardness changes of the experimental alloy. The results show softening of the irradiated material compared to the un-irradiated material, with the softening being more pronounced at the higher dose. Cross-sectional transmission electron microscopy characterisation reveals that γ′-precipitate instability (disordering/dissolution) is the main reason for the softening behaviour and this outweighs the hardening effect of irradiation-induced defects.
Acknowledgments
The authors wish to thank Professor Mark Daymond for fruitful discussion and RMTL (Reactor Materials Testing Laboratory) equipment support through the NSERC/UNENE/Nu-Tech Precision Metals Industrial Research Chair Program at Queen’s University. The irradiation was performed in the Department of Physics of the University of Montreal. In this regard, we wish to thank Professor Sjoerd Roorda and Martin Chicoine for their kind help.