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Features and Benefits
Quantitative mechanical properties
data may be obtained at
multiple depths from a single
indentation test. Obtaining the
same data would require tens
or even hundreds of tests using
the conventional method.
Since the contact stiffness
is determined directly, no
assumptions (such as “mechanical
equilibrium”) are
required to correct for elasticity.
As a result, property
measurements are inherently
more accurate using CSM.
The point of initial surface
contact may be accurately
determined during the test.
Indentation tests using CSM
may be controlled with a constant
strain rate, a critical test
parameter for material systems
such as polymer films and film/
substrate systems, pure metals,
or low-meltingpoint alloys. This
level of control is impossible
with the conventional method.
By measuring both the amplitude
and phase relationships
between the load and displacement
oscillations, it is possible
to determine the loss modulus
for viscoelastic materials.
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Until recently, acquiring mechanical data in the nanometer range has posed a technical
challenge. But, nanoindentation systems from MTS now make it possible to characterize
mechanical properties (such as modulus of elasticity, loss modulus, and fracture
behavior) in the nanometer range using both quasi-static and dynamic methods.
The accuracy and reliability of mechanical properties
depend on more than the accuracy of the tip
geometry and the force and displacement measurements.
To accurately calculate the contact area
and mechanical property values, the stiffness of
the contact between the indenter tip and the sample
material must also be accurately determined.
QUASI-STATIC AND DYNAMIC METHODS
MTS NANO Indenter systems support both
quasi-static and dynamic depth-sensing indentation
methods. In quasi-static indentation
testing the stiffness of contact is determined
by analyzing the force vs. displacement curve
during unloading. This conventional depthsensing
method provides a single measurement
for the given indentation depth.
While the quasi-static method is suitable for
many applications, an enhanced method is
needed for applications that must take into
account dynamic effects, such as strain rate
and frequency. To address these needs, MTS
provides dynamic nanoindentation methods,
through the patented Continuous Stiffness
Measurement (CSM) technique.
With the CSM extension, the NANO Indenter
system applies a load to the indenter tip to
force the tip into the surface while simultaneously
superimposing an oscillating force with
a force amplitude generally several orders of
magnitude smaller than the nominal load.
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We use amplitude, ratio, and phase shift to determine stiffness continuously with indenter penetration.
The CSM instrument extension offers a means
of then separating the in-phase and out-of-phase
components of the load-displacement
history, providing an accurate measurement
of the contact stiffness at all depths. Material
properties are determined continuously
as the indenter moves into the surface,
eliminating the need for unloading cycles.
The state-of-the-art CSM instrument
extension provides the only means available
to fully characterize dynamic properties
in the nanometer range for virtually
any material of interest.
MTS NANO Indenter systems are carefully
designed to account for the dynamics
of indentation testing. Each system is individually
calibrated and characterized over
its full dynamic range of operation to assure
maximum accuracy and reliability.
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Download CSM PDF
Contact MTS
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