Hardness cartography to increase the nanoindentation resolution in heterogeneous materials: Application to a Ni-based single-crystal superalloy

Statistics on nanoindentation experiments performed on a fourth-generation Ni-based single-crystal superalloy reveal a bimodal hardness distribution, with two mean hardness values only 2.5% away from each other. Using a hardness cartography technique combined with the statistical analysis proved that the hardness values are not randomly distributed but correspond exactly to the dendrites and the interdendritic regions. In this context, hardness cartography is shown to push back the resolution limit of the nanoindentation test.