Instrument indentation testing, commonly referred to as nanoindentation, is more than the conventional hardness measurement. Using the conventional hardness measurement, parameters such as the Vickers hardness can be determined. In thin layers, like those on sensors, optical lenses or cutting tools, the conventional hardness measurement has it’s limitations.
Disadvantages of conventional hardness measurement:
- Large uncertainty in the optical length measurement for small penetration depths required for thin films to avoid substrate effects
- Large operator influence because of the optical measurement
- Dark or dull surfaces require material for the optical measurement of an elaborate pre-treatment
- Hardness value is solely a measure of plastic material properties – there is no information on the elastic or visco-elastic properties available
- Can not be used for especially on elastic materials where imprint left by indent is very small because of elastic recovery
Advantages of Instrumented indentation test:
- Measurement of elastic and plastic material properties with every measurements
- Measuring thin layers without the influence of the base material
- No operator influence because of automated measurement method
- High productivity also because of automated measurement method
All Devices by FISCHER work with the instrumented indentation. This makes it possible to determine the following material parameters:
Measurable material parameters calculation of material parameters according to DIN EN ISO 14577-1 and ASTM E 2546:
Martens hardness HM
Indentation hardness HIT (Convert to Vickers Hardness HV)
Elastic indentation modulus EIT
Indentation creep CIT
Percent elastic deformation component ηIT the indentation Welast / Wtotal
Other parameters such as the Martens hardness at a certain test load, plastic deformation intensity etc.
Enhanced Stiffness Procedure (ESP) – This material parameters, such as HIT and EIT can be determined as a function of depth.