Agilent Technologies Nano Indenter G200 - Page 316

Theory 7
Agilent Nano Indenter G200 User’s Guide 7-19
The reduced modulus of fused silica is known because the properties are
known:
For diamond, E = 1140 GPa and n = 0.07. For fused silica, E = 72 GPa
and n
= 0.18, yielding:
(23)
The following parameters are needed for semi-static methods for
determination of indenter area function.
Contact Stiffness is defined as:
(24)
Contact Depth is defined as:
(25)
Contact Area is defined as:
(26)
Each indentation provides one ordered pair of (h
c
,A) as shown in
Figure 7-12 on page 7-20.
E
r
1 0.18
2
–
72
---------------------------
1 0.07
2
–
1140
---------------------------+ 69.87GPa==
S
dP
dh
-------
h
max
=
h
c
h
max
0.75P
max
S
-----------------------–=
A

4
---
S
E
r
-----


2
=