Influence of modulus-to-hardness ratio and harmonic parameters on continuous stiffness measurement during nanoindentation

abstract

• 2017 Acta Materialia Inc. Dynamic nanoindentation is a popular method for continuously probing the mechanical properties of a sample as a function of depth. It is shown here that special caution should be exercised when testing materials with high modulus-to-hardness ratios (E/H) at fast loading rates, as the choice of harmonic parameters can result in a significant underestimation of the contact stiffness and hence the elastic modulus. The origin of this behavior is traced back to a bias occurring during signal processing by the lock-in amplifier. The possible consequences of flawed measurements are highlighted and a practical method for detecting possible occurrence from the phase angle signal is presented.

authors

• Pharr, George

published proceedings

• ACTA MATERIALIA

altmetric score

• 3

author list (cited authors)

• Merle, B., Maier-Kiener, V., & Pharr, G. M.

citation count

• 60

complete list of authors

• Merle, Benoit||Maier-Kiener, Verena||Pharr, George M

publication date

• August 2017

publisher

• Elsevier  Publisher

published in

• ACTA MATERIALIA  Journal

keywords

• Continuous Stiffness Measurement
• Harmonic Parameters
• Lock-in Amplifier
• Nanoindentation
• Stiffness Bias

Digital Object Identifier (DOI)

• 10.1016/j.actamat.2017.05.036

start page

• 167

end page

• 176

volume

• 134

URL

• http://dx.doi.org/10.1016/j.actamat.2017.05.036