Characterization of Indentation Size Effect of Hardness Using a Loading Curve from Crystalline Materials
Nanoindentation technique has been widely used for measuring mechanical properties from a very small volume of material. The hardness measured using the depth sensing nanoindentation technique often decreases with increasing indentation size, the so called indentation size effect (ISE)[1, 2]. It has been generally acknowledged that the ISE in crystalline materials originates from the density change of geometrically necessary dislocations (GND) needed to accommodate a permanent indentation imprint. Conventionally, to characterize an ISE often requires a series measurement of hardness values at different indentation size. Based on the celebrated Oliver-Pharr scheme. We propose a method to derive the ISE from the loading curve of one single indentation test. The application and limitation of the proposed method will be discussed.
Deliang Zhang, Kim Pickering, Brian Gabbitas, Peng Cao, Alan Langdon, Rob Torrens and Johan Verbeek
Y.L. Chiu and W. G. Ferguson, "Characterization of Indentation Size Effect of Hardness Using a Loading Curve from Crystalline Materials", Advanced Materials Research, Vols. 29-30, pp. 55-58, 2007