Nanoindenters, also known as depth-sensing indenters or instrumented indenters, are instruments designed to quantitatively measure the mechanical properties of small volumes of material. Nanoindenters operate by pressing a nanoindentation probe into the surface of a material and measuring the relationship between applied probe force and the resulting probe displacement. The force vs. displacement curve is the mechanical fingerprint of the material from which quantitative mechanical properties can be calculated at the nanoscale.
Indentation testing has been utilized for over a century to measure the hardness of materials. In a traditional hardness test the size of the residual indent impression needs to be physically measured to obtain a hardness value (function of applied force divided by the size of the indent impression). The requirement to measure the residual indent dimensions places a lower limit on the scale of testing that can be efficiently and reliably performed. The depth-sensing capabilities of nanoindenter systems eliminate the need for measuring the size of the indent impression, increasing the accuracy, precision, and throughput of small volume mechanical property characterization.
Nanoindenter systems are not only utilized for the characterization of thin films and low dimensional materials, but are also routinely utilized to accelerate the development of bulk engineered materials. The ability to characterize individual grains/phases/interfaces within a bulk material provides a greater understanding of structure-property-processing-performance relationships. Quantitative mechanical characterization at the nanoscale combined with structure-property optimization is one of the foundations of today’s material development initiatives.
Nanoindenter systems are used to quantitatively measure a variety of nanoscale mechanical properties. In addition to hardness measurements, nanoindenter-based techniques enable elastic modulus, creep, stress relaxation, viscoelastic properties, interfacial adhesion, and fracture toughness characterization at sub-micrometer length scales.