Martens hardness of Constantan thin films on (100) Si wafer: Improvement in contact area function in nanoindentation

•Hardness of the substrate changes according to the film thickness (Constantan).•Application of indentation size effect models allows an adequate representation of data.•Stability of constantan martens hardness value when considering the indenter tip defect.•The effect of cracks in substrate on film behaviours.•Containment of the film between indenter and substrate effect on film behaviours.