Quasi-static Nanoindentation | Bruker

Quasi-Static Nanoindentation: An Overview

Quasi-static nanoindentation has become the standard technique used for nanomechanical characterization of materials. A quasi-static nanoindentation test is performed by applying and removing a load to a sample in a highly controlled manner with a geometrically well-defined probe.

During the nanoindentation process, a force is applied by the transducer and the probe displacement is continuously measured to produce a traditional force vs. displacement curve. The resulting force vs. displacement curve serves as the 'mechanical fingerprint' of the material, from which quantitative nanoscale material properties can be determined. Bruker's Hysitron nanoindenters measure the force and displacement of the nanoindentation probe with a unique three-plate capacitive transducer design. This transducer design provides an unsurpassed noise floor and ultra-low working force.

The tightly controlled construction and calibration standards used for the capacitive transducer in combination with the precisely machined, rigid nanoindentation probes produce quantifiable, reliable measurement on any material.

Analysis of the measured force vs. displacement curve (particularly the unloading segment) provides the user with quantitative information regarding the mechanical properties of the sample. Values typically obtained from quasi-static nanoindentation testing are Reduced Modulus (Er) and Hardness (H). However other information such as fracture toughness, stiffness, delamination force, and film thickness can also be obtained.

All Hysitron standalone nanoindentation systems are capable of in-situ SPM imaging. Using the same probe to scan a sample surface immediately before and/or after a test allows for precise placement of the test as well as observation of deformation events or sample recovery after the test.

Quasi-static nanoindentation from Bruker is designed for maximum versatility. Our capacitive quasi-static nanoindentation transducer technologies cover a force range from 2nN to 10µN, providing characterization capabilities on the widest range of materials.


Quasi-static Nanoindentation | Bruker

Fig. 1. (A) Force vs. displacement curve on fused quartz showing typical response of elastic-plastic material. (B) Resulting in-situ SPM image of quartz surface after quasi-static nanoindentation showing residual indent impression.


How Quasi-Static Nanoindentation Works

Bruker's nanoindentation transducer is unique in its operation and is the only nanoindenter system in the world to use the three-plate capacitive design. Displacement is measured by running two AC signals that are 180° out of phase with each other to the top and bottom plate of the three-plate capacitive sensor. The AC signals are observed by the center (floating) plate and the sum of the signals corresponds to a measured displacement. To apply a load, a DC offset is applied to the lower plate of the transducer that electrostatically attracts the center plate downward. The resulting difference in the sums of the AC signals results  in an offset in the sum of the AC signals and thus a change in displacement.


Quasi-static Nanoindentation Transducer | Bruker

Fig. 2. Schematic showing an explanation of Bruker's three-plate capacitive transducer operation for high accuracy force application during nanoindentation.


Quasi-Static Nanoindentation Data Analysis

Hysitron nanoindentation systems include a quasi-static data analysis package that uses a standard model to fit the initial unloading portion of the force vs. displacement curve to extract the Reduced Modulus (Er) and Hardness (H) values.

Quasi-static testing enables the nanoindentation probe area function to be calculated using an advanced analysis software package to ensure any variations in probe geometry are accounted for.


Quasi-static Nanoindentation Analysis | Bruker

Fig. 3. Analysis from quasi-static nanoindentation tests showing curve fit over increasing load indentation testing for calibration of probe shape.


Mechanical Properties Measured Using Nanoindentation

Nanoindentation is a powerful technique used to quantitatively characterize the mechanical properties of small volumes of material. By fitting the appropriate models to the force vs. displacement curve obtained during the test, material properties such as elastic modulus, hardness, creep, stress relaxation, interfacial adhesion, and fracture toughness can be measured at the nanoscale and microscale.


Nanoindentation Test Equipment

A wide variety of test equipment and application-specific techniques are available to perform nanoindentation testing. For general information about nanoindentation test equipment, see our Hysitron Nanoindenter Overview page.

Hysitron Standalone Nanoindentation Equipment

Hysitron TI 980 TriboIndenter | Bruker

TI 980 TriboIndenter

Bruker's most advanced nanomechanical and nanotribological test instrument, operating at the intersection of maximum performance, flexibility, reliability, sensitivity and speed.

Hysitron TI 950 TriboIndenter | Bruker

TI 950 TriboIndenter

Versatile nanomechanical and nanotribological test instrument, supporting a broad range of hybrid and correlative characterization techniques.

Hysitron TI Premier | Bruker

TI Premier

Dedicated nanomechanical test instruments, providing an essential toolkit for nanoscale mechanical characterization within a compact platform.

Hysitron Nanoindentation Equipment Interfaced to Microscopy Systems

Hysitron PI 85L SEM PicoIndenter | Bruker

PI 85L SEM PicoIndenter

Depth-sensing nanomechanical test instrument that can be interfaced with scanning electron microscopes (SEM).

Hysitron PI 88 SEM PicoIndenter | Bruker

PI 88 SEM PicoIndenter

Bruker’s comprehensive nanomechanical test instrument for SEM and FIB/SEM, featuring our full suite of techniques.

 

Hysitron PI 95 TEM PicoIndenter | Bruker

PI 95 TEM PicoIndenter

The first full-fledged depth-sensing indenter capable of direct-observation nanomechanical testing inside a transmission electron microscope (TEM).

 

Hysitron IntraSpect 360 | Bruker

IntraSpect 360

Quantitative in-situ mechanical property characterization specifically designed for X-Ray microscopes (XRM) and beamlines.

Hysitron TS 75 TriboScope | Bruker

TS 75 TriboScope

Quantitative, rigid-probe nanoindentation and nanotribological characterization on your existing AFM.

Hysitron BioSoft In-Situ Indenter | Bruker

BioSoft In-Situ Indenter

The first of its kind instrument for multiscale quantitative mechanical testing of biological materials and hydrogels.