Related Experiment Video
Updated: May 19, 2026
08:21
Quantitative Hardness Measurement by Instrumented AFM-indentation
Published on: November 22, 2016
Penetration resistance and penetrability in pyramidal (nano)indentations
Gerd Kaupp1, Mohammad Reza Naimi-Jamal
1Faculty 5, University of Oldenburg, Edewecht, Germany. gerd.kaupp@uni-ldenburg.de
Scanning
|August 14, 2012
Summary
This study introduces a new method for analyzing nanoindentation loading curves by plotting normal force against penetration depth to the power of 3/2. This approach accurately captures material properties and phase transitions, outperforming traditional methods.
Area of Science:
- Materials Science
- Nanotechnology
- Mechanical Engineering
Background:
- Traditional nanoindentation analysis often fails to account for complex material behaviors like phase transitions and surface effects.
- Existing methods, including finite element (FE) calculations, can produce experimentally unsupported loading curves.
Purpose of the Study:
- To develop and validate a novel analysis method for nanoindentation loading curves.
- To accurately characterize material properties and identify phase transitions during indentation.
Main Methods:
- Linear plotting of normal force versus (penetration depth)(3/2) for pyramidal nanoindentation.
- Analysis of the slope (penetration resistance k) and its inverse (penetrability).
- Identification of kinks in the linear plot to signify phase transitions, such as twinning.
Main Results:
- Linear correlations were consistently observed, validating the (penetration depth)(3/2) exponent for various materials and indentation types.
- The penetration resistance analysis successfully recognized features missed by common curve fitting and FE calculations, including phase transitions, gradients, and surface effects.
- A deviation from established theories (Sneddon's and Love's) was explained by correcting for the shear-force component not contributing to penetration depth.
Conclusions:
- The (penetration depth)(3/2) exponent provides a robust framework for analyzing nanoindentation data, offering superior accuracy over existing methods.
- This method enhances the understanding of material behavior under indentation, particularly in the presence of complex phenomena like phase transitions.
- The findings necessitate an adjustment of mechanical parameters previously defined using unsupported exponents.
