Yield behavior of ion-irradiated metal and alloys measured by nanoindentation

In general, ion irradiation produces a shallow damaged layer beneath the surface of materials. The yield behavior and mechanism of this irradiation-damaged layer are still not clear, and there is a scarcity of techniques for assessing the mechanical properties of such minute volumes material. In this paper, a nanoindentation stress–strain relationship is established to investigate the yield behavior of ion-irradiated materials including Be, Fe-10Cr and CuAlMn alloys. The findings indicate that the initial yield stress of ion-irradiated layer in which dislocation loops and/or cavities are present increase, and even a significant yield platform can be observed through the established nanoindentation stress–strain curves. Additionally, the difference in yield behavior caused by the phase transformation can also be clearly reflected. This underscores the utility of the established indentation stress–strain relationship in providing insights into the elastic–plastic properties of ion irradiated materials.