Oluschinski: Created page with "{{Language_sel|LANG=ger|ARTIKEL=Nano-Eindringprüfung}} {{PSM_Infobox}} Nanoindentation testing FORCETOC ==Classification within nanoindentation testing== Nanoindentation plays a key role in the testing and evaluation of the mechanical properties of miniature components (see: testing microcomponents) [1]. This indentation testing method is one of the Hardness#Instrumented hardness..."

2026-09-04T09:33:31Z

Created page with "{{Language_sel|LANG=ger|ARTIKEL=Nano-Eindringprüfung}} {{PSM_Infobox}} Nanoindentation testing __FORCETOC__ ==Classification within nanoindentation testing== Nanoindentation plays a key role in the testing and evaluation of the mechanical properties of miniature components (see: testing microcomponents) [1]. This indentation testing method is one of the Hardness#Instrumented hardness..."

New page

{{Language_sel|LANG=ger|ARTIKEL=Nano-Eindringprüfung}}
{{PSM_Infobox}}
Nanoindentation testing
__FORCETOC__

==Classification within nanoindentation testing==

Nanoindentation plays a key role in the testing and evaluation of the mechanical properties of miniature components (see: [[Testing Microcomponents|testing microcomponents]]) [1]. This indentation testing method is one of the [[Hardness#Instrumented hardness testing|instrumented hardness testing]] methods, i.e. it can be used to determine [[Hardness|hardness]] values, [[Elastic Modulus|moduli of elasticity]] and fracture mechanics parameters (see: [[Fracture Mechanical Testing|fracture mechanical testing]]) [2]. The distinctive feature of this method lies in its high resolution in terms of load and indentation depth.

==Technical data==

Typical technical specifications for a nanoindenter are given below as an example:

{|
|-valign="top"
|Maximum load:
|500 mN
|-valign="top"
|Load resolution:
|50 nN
|-valign="top"
|Penetration depth resolution:
|0.02 nm
|-valign="top"
|Maximum penetration depth:
|>> 40 µm
|-valign="top"
|Positionig accuracy:
|1 µm, some instruments achieve [[Measured Value Accuracy|measured value accuracy]] of up to 0.2 µm
|-valign="top"
|Indenter shapes:
|Berkovich, Vickers (see: [[Indenter|indenter]]), cone, special shapes
|-valign="top"
|Minimum load rate:
|<math>\le</math> 1 mN s-1
|-valign="top"
|Maximum load rate:
|<math>\ge</math>7 <math>\cdot</math>1010 µN s-1.
|}

==Material Parameter==

This provides the experimental capability to determine, directly within complex [[Plastic Component|components]] composed of different [[Material & Werkstoff|materials]], the [[Hardness|hardness]], [[Elastic Modulus|modulus of elasticity]] and, in some cases, the [[Fracture Mechanics|fracture toughness]] ''K''Ic of the individual materials. Furthermore, these instrument systems offer additional applications for continuous [[Tensile Test Compliance|stiffness measurement]], in which an additional oscillation is superimposed on the load-penetration depth signal; this enables scratch functions to be implemented and allows the measurement of normal and tangential loads.

In addition to determining the material properties of individual components within a part, this method can be used to determine interfacial properties. For this purpose, the application of the [[Indentation Fracture Mechanics|indentation fracture mechanics]] method – or, for low loads, nano-fracture mechanics – has proven effective.

==Indentation fracture mechanics==

However, the conventional approach, which relies on measuring the radial cracks formed beneath the indenter, reaches its limits, as certain critical loads are required to generate radial [[Crack|cracks]]. When using [[Indenter|indenter shapes]] in accordance with the Vickers or Berkovich methods, these loads depend on the material and the indenter geometry. However, the resulting penetration depths are too great for the [[Testing|testing]] of thin and ultra-thin layers, meaning that the elastic-plastic zone can reach the substrate. It is also very difficult to measure the radial [[Crack|cracks]] at very small penetration depths using a [[Scanning Electron Microscopy|scanning electron microscope (SEM)]]. The [[Fracture Mechanics|fracture toughness]] ''K''Ic can be determined according to '''Eq. (1)'''.

{|
|-
|width="20px"|
|width="500px" | <math>K_{Ic}\,=\,0{.}016\, \left( \frac{E}{H\, V} \right)^\frac{1}{2} \cdot \frac{F}{c^ \frac{3}{2}}</math>
|(1)
|}

with
{|
|-
|''HV''
|width="15px" |
|[[Vickers Hardness|Vickers hardness]]
|-
|''c''
|
|crack length (measured from the centre of the indentation)
|}

Based on findings in the literature [3–7], a method for determining interlaminar fracture toughness (see also: [[Interlaminar Shear Strength|interlaminar shear strength]]) is described and tested using the example of a thin polystyrene ([[Plastics – Symbols and Abbreviated Terms|abbreviation]]: PS) layer on a glass substrate; to generate sufficient elastic strain energy in the PS, a polymethyl methacrylate ([[Plastics – Symbols and Abbreviated Terms|abbreviation]]: PMMA) layer was additionally applied as a ‘superlayer’.

==Example of nanoindentation testing on a multilayer system==

The '''Figure''' shows a schematic representation of an applied PMMA superlayer, used to determine the interfacial adhesion between PS and glass by means of a penetration test. This procedure is necessary because, in the presence of a [[Ductility Plastics|ductile]] layer on a brittle substrate, it is very difficult or impossible to achieve layer delamination, as insufficient elastic strain energy is generated within the layer. The use of a conical indenter (90°) with a tip radius of 1 µm results in the desired separation of the [[Phase Boundary Surface|interfaces]] in the PS/glass system.

The fracture process in a multilayer system proceeds in three stages, which can be observed in a load (''F'')-penetration depth (''h'') curve. In stage 1, the first annular [[Crack|cracks]] are observed through the layer due to the high stresses in the contact zone. Stage 2 is characterised by the delamination and bulging of the layer due to the high lateral compressive stresses (see: [[Compression Test|compression test]]). Stage 3 is caused by the layer being breached and results in a jump in the loading curve.

For Stage 3, the fracture toughness (see: [[Fracture Mechanics|fracture mechanics]]) can be calculated according to '''Eq. (2)'''

{|
|-
|width="20px"|
|width="500px" | <math>K_{Ic}\,=\,\left[ \left( \frac{E}{\left( 1- \nu^2 \right) \cdot 2\, \pi\, c_R} \right)\cdot \left( \frac{U}{h} \right)\right]^\frac{1}{2}</math>
|(2)
|}

where, for very thin layers, the crack length ''c''R is usually determined using a [[Scanning Electron Microscopy|scanning electron microscope (SEM)]], and the energy released ''U'' is calculated, as shown in the '''Figure''', as the area enclosed by A, B and C.

[[File:Nanoind.jpg|600px]]
{|
|- valign="top"
|width="50px"|'''Fig.''':
|width="600px" |Schematic cross-sectional structure for demonstrating phase adhesion at a PS/glass interface with a PMMA superlayer (a) and a schematic load-penetration depth curve showing the stages of the fracture process for determining the energy released (b)
|}

==See also==

* [[Instrumented Hardness Testing – Method & Material Parameters|Instrumented hardness testing – Method & material parameters]]
* [[Testing Microcomponents|Testing microcomponents]]
* [[Surface Testing Technology|Surface testing technology]]
* [[Non-destructive Testing (NDT)|Non-destructive testing (NDT)]]

==References==

{|
|-valign="top"
|[1]
|Michel, B., Walter, H.: Mikroprüftechnik. In: [[Grellmann,_Wolfgang|Grellmann, W.]], [[Seidler,_Sabine|Seidler, S.]] (Eds.): Kunststoffprüfung. Carl Hanser, Munich (2025) 4th Edition, pp. 707–709 (ISBN 978-3-446-44718-9; E-Book: ISBN 978-3-446-48105-3; see [[AMK-Library]] under A 23)
|-valign="top"
|[2]
|[https://www.researchgate.net/profile/Wolfgang-Grellmann Grellmann, W.], [https://www.researchgate.net/profile/Sabine-Seidler Seidler, S.] (Eds.): Kunststoffprüfung. Carl Hanser, Munich (2025) 4th Edition, pp. 196 ff (ISBN 978-3-446-44718-9; E-Book: ISBN 978-3-446-48105-3; see [[AMK-Library]] under A 23)
|-valign="top"
|[3]
|Li, X., Bushan, B.: Measurement of fracture toughness of ultra-thin amorphous Carbon films. Thin Solid Films 315 (1998) 214–221; [https://doi.org/10.1016/S0040-6090(97)00788-8 https://doi.org/10.1016/S0040-6090(97)00788-8]
|-valign="top"
|[4]
|Li, M., Carter, C. B, Hillmyer, M. A., Gerberich, W. W.: Adhesion of polymer-inorganic interfaces by nanoindentation. J. Mater. Res. 16 (2001) 3378–3388; [https://doi.org/10.1557/JMR.2001.0466 https://doi.org/10.1557/JMR.2001.0466]
|-valign="top"
|[5]
|Lu, Y., Shinozaki, D. M.: Microindentation induced debonding of polymer thin films from rigid substrates. J. Mater. Science 37 (2001) 1283–1293; [https://doi.org/10.1023/A:1014506823464 https://doi.org/10.1023/A:1014506823464]
|-valign="top"
|[6]
|Li, M., Palacio, M. L., Carter, C. B., Gerberich, W. W.: Indentation deformation and fracture of thin polystyrene films. Thin Solid Films 416 (2002) 174–183; [https://doi.org/10.1016/S0040-6090(02)00613-2 https://doi.org/10.1016/S0040-6090(02)00613-2]
|-valign="top"
|[7]
|Rosenfeld, L. G., Ritter, J. E., Lardner, T. J., Lin, M. R.: Use of microindentation technique for determining interfacial fracture energy. J. Appl. Phys. 67 (1990) 3291–3296; [https://doi.org/10.1063/1.345363 https://doi.org/10.1063/1.345363]
|}

[[Category:Hardness]]
[[Category:Surface Testing Technology]]

Nanoindentation Testing - Revision history