Critical issues in conducting constant strain rate nanoindentation tests at higher strain rates

Merle B, Higgins WH, Pharr GM (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Journal of Materials Research Cambridge University Press

DOI: 10.1557/jmr.2019.292

Abstract

Constant strain rate nanoindentation is a popular technique for probing the local mechanical properties of materials but is usually restricted to strain rates ≤0.1 s-1. Faster indentation potentially results in an overestimation of the hardness because of the plasticity error associated with the continuous stiffness measurement (CSM) method. This can have significant consequences in some applications, such as the measurement of strain rate sensitivity. The experimental strain rate range can be extended by increasing the harmonic frequency of the CSM oscillation. However, with commercial instruments, this is achievable only by identifying higher CSM frequencies at which the testing system is dynamically well behaved. Using these principles, a commercial system operated at the unusually high harmonic frequency of 1570 Hz was successfully used to characterize of the strain rate sensitivity of a Zn22Al superplastic alloy at strain rates up to 1 s-1, i.e., an order of magnitude higher than with standard methods.

Authors with CRIS profile

Benoit Merle Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Additional Organisation(s)

Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM) Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Related research project(s)

SPP 2074 Fundamental multiscale investigations for improved calculation of the service life of solid lubricated rolling bearings April 1, 2019 - March 31, 2022

Involved external institutions

Texas A&M University US United States (USA) (US)

How to cite

APA:

Merle, B., Higgins, W.H., & Pharr, G.M. (2019). Critical issues in conducting constant strain rate nanoindentation tests at higher strain rates. Journal of Materials Research. https://dx.doi.org/10.1557/jmr.2019.292

MLA:

Merle, Benoit, Wesley H. Higgins, and George M. Pharr. "Critical issues in conducting constant strain rate nanoindentation tests at higher strain rates." Journal of Materials Research (2019).

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