A hardening model for the cross-sectional nanoindentation of ion-irradiated materials

In this paper, a hardening model is developed for the cross-sectional nanoindentation of ion-irradiated materials. The model is based on the derivation of an average defect density within the formed plasticity affected region, which depends on the distribution of defect density in the irradiated region, indentation depth and distance from the irradiated sample surface. A succinct parameter calibration process is proposed by comparing the theoretical results with experimental data at a given indentation depth. A good agreement with experimental data can be achieved for both the fitted relationship between irradiation hardening and indentation distance from the irradiated sample surface under cross-sectional nanoindentation, and predicted hardness as a function of indentation depth under surface nanoindentation. Therefore, the rationality and accuracy of the proposed model are effectively verified. Based on the analysis of this proposed model, it is available to characterize the property of plasticity affected region and irradiation depth of ion-irradiated materials based on the experimental data measured through cross-sectional nanoindentation.