Calculation of Indent't Real Contact Projection Area in Nanoindentation

Real contact projection area is a key parameter of the evaluation models of the materials' mechanical properties using nanoindentation. If the geometrical parameters of the indenter are known, the real contact projection area may be determined based on the relation between the real contact depth determined according to the unloading curve and the geometrical parameters of the indenter and the real contact projection area. If the real geometrical parameters of the indenter are not known, the real contact projection area is obtained using testing method. In this paper, two kinds of testing methods, the standard block method (including the standard elastic modulus block method and the standard hardness block method) and the non-standard block method, are introduced for the determination of the real contact projection area