Hardness Nanoindentation Measurements

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Hardness / Nanoindentation Measurements
MSE 333 6/4/08
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• Hardness Test
• Quick and dirty way of evaluating and comparing
  mechanical properties of materials.
• Does NOT measure intrinsic material property -
  system and size scale dependent.
• Considered as a nondestructive.

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Hardness Test Techniques
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(No Transcript)
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H cY
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Cook Pharr, J Am Cer Soc, 1990
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Nanoindentation Techniques
Vertical
Cantilever
F
F
F
Force Range mN to 10 mN 50 nN to 500 mN Tip
Radius 60 to 100 nm 60 to 100 nm
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Nanoindentation
F
F
Nanoindentation Control Unit
SPM
Sample
H P/Ac Er (S/2)(p/Ac)1/2
3-D Piezo Scanner
Diamond Tip
Sensitivity 2 mN Tip radius 50 - 80 nm
Berkovich
Cube Corner (higher stress intensity)
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H P/Ac Er (S/2)(p/Ac)1/2
Oliver Pharr, 1992
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Nanoindentation
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Hard Layer
H 12.7GPa Er 205.9GPa
Hard Layer
H 13.2GPa Er 208.6GPa
Hard Layer
H 36.6GPa Er 302.7GPa
Epoxy
Metal
Figure 2 Indentations by the drill bit surface
of treated X104DT. Shown in (a) is a 80mm scan
before indentation. Shown in (b) and (C) are
zoom-in views (10mm scan) of the bit surface
after indentations,revealing a 2mm thick hard
layer.
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H 21.7GPa Er 228.9GPa
H 21.8GPa Er 227.4GPa
H 13.3GPa Er 212.6GPa
H 23.2GPa Er 223.8GPa
H 12.7GPa Er 210.9GPa
H 10.8GPa Er 202.1GPa
Figure 3 Example of indentations made in the
interior of a drill bit showing circular pits
that have higher hardness values than the rest of
the matrix metal. Pits are strained interface
between the matrix and iron carbide precipitates
eroded by polishing. (Scan size 10mm)
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Fig. 19. Plot of film modulus predicted by the
modified King solution for the (a) 0.5 mm and (b)
2.0 mm Al films on different substrates. The
prediction matches the expected film modulus of
73 GPa reasonably well for indentation depths
less than 50 of the film thickness.