Nanoindentation (Nano-indent)

Nanoindentation (nano-indent) is a quasi-static mode of nanomechanical analysis used to measure the hardness and reduced elastic modulus of solid samples. It is especially useful for evaluating thin film coatings.

Strengths

• Quick measurement
• Accesses many mechanical properties through computational analysis
• Hardness test for films greater than 10 nm thick
• Minimal sample preparation required

Limitations

• Destructive
• Works best for linear, isotropic samples
• Soft materials and adhesives can introduce measurement error
• Interpretation is challenging if films are less than 100 nm and/or surface is rough

Learn More

Example Outputs Instruments Used How Nano-indent Works

• Medium to hard solids (10 GPa – 100 MPa)
• Flat surface for best result
• Samples cut to 2 cm x 2 cm to fit in Hysitron enclosure

To make a nanoindentation measurement, an indenter tip (made of a material much harder than the sample: commonly diamond) is pressed into the sample surface. A force is applied to the tip and increased until it penetrates the surface to a user-defined stopping point. The force is then held for a preset duration of time, followed by unloading and retracting from the surface.

While the tip is pressed and released from the surface, a force vs. displacement curve is measured. Hardness and modulus are calculated instantaneously by the tool.

Typically an array of indents are done to provide reasonable measurement statistics and eliminate outlier measurements from issues such as surface particulates.

Hardness is determined by calculating the ratio of the maximum force to the area of the tip. Modulus is determined by fitting the unload-curve to a linear slope.