NanoTest™ instruments offer excellent instrumented indentation performance across a wide load range of 1 µN – 30 N. Usually instrumented indentation is used for measurement of hardness and elastic modulus. It is also possible to quickly and accurately profile mechanical properties as a function of depth and to map properties across areas. Indentation experiments may also be used for a wide range of other purposes including; measurement of time-dependent properties (creep), indentation stress-strain tests, micro-pillar compression, micro-cantilever bending, fibre push-out, fracture toughness etc. 100 nanoindentation measurements on a fused silica reference sample. Most nanoindentation work for measurement of hardness and elastic modulus is performed using a three sided “Berkovich” indenter. Many other indenter geometries are available for different test types. The load-partial unload (multi-cycle) indentation technique allows for the rapid profiling of hardness and elastic modulus variation as a function of depth. In this example, a 50-cycle test from 5 mN to 100 mN was performed on a 2 µm DLC coating on silicon. The inset plot shows decreasing hardness as the influence of the softer silicon substrate increases with increasing indentation depth. Very low noise floor and thermal drift rates mean that high measurement accuracy is retained down to very small contact depths. Here three samples with low friction coatings have been profiled down to contact depths of 5 nm. Mechanical properties may be mapped across areas as small as 1μm² up to several cm². In this case the elastic modulus of four calcite crystals of a Pinna Nobilis shell have been mapped over and area of 45 x 45 µm. The crystals of interest were first identified using EBSD, the sample was then transferred to the NanoTest Vantage and the region of interest targeted using the instrument’s integrated optical microscope. Once tests are complete a full statistical analysis of the results is possible within the NanoTest™ Vantage™ software. A wide range of other tests are also possible using instrumented indentation, these include: Micro-pillar compression Micro-cantilever bend tests Fibre push-out tests Adhesion tests (pull-off force) Particulate compression tests This example demonstrates micro-pillar compression of an IN718 superalloy. Tests were performed in displacement rate controlled mode and load-drop events are seen in response to transient deformation events in the pillar.
