Specimen heater up to 400°C for high-temperature nanoindentation
The specimen heater can be installed in the ZHN in place of the standard specimen holder. It uses passive cooling and does not require any water supply. This enables the measuring of lateral forces and scratch testing without lateral force contribution.
Two heating circuits are used. A heating plate is situated under the specimen and a heating cylinder sits in a cover above the specimen. An extended Macor rod with indenter tip at the end reaches into the cover and is heated together with the volume of compressed air above the specimen. PT100 temperature sensors are integrated in the heating elements.
The top cover can be removed after the test. A visual inspection of the specimen surface can be preformed using a long-range lens so that positioning accuracy is not lost. Specimen and heating plate are pressed from below against a stop. No adhesive is needed to fix the specimen.
Measuring heads for the ZHN nanoindenter
The ZHN universal nanomechanical tester combines two measuring heads in the normal (nanodindenter principle) and lateral (scratch tester principle) directions, operating completely independently of each other with nanometer resolution. Lateral force-displacement curves can now be measured for the first time, allowing more material parameters to be obtained than was previously possible (see Typical Applications). This includes measurement of the lateral stiffness and purely elastic lateral deformation of the specimen.
In contrast to instruments by other manufacturers, both measuring heads operate in both tensile and compression directions, enabling indentation tests with a superimposed oscillation as well as cyclic fatigue tests.
Normal Force Unit (NFU)
- Movement in the normal direction and high stiffness in the lateral direction thanks to the double leaf-spring system
- Robust construction
- No inductive sensor stop in the event of an overload and thus no damage
- The shaft can bear heavier weights without leaving the measurement range Any kind of customer-specific probes can be easily used
Lateral Force Unit (LFU)
- Specimen grips with the specimen in the middle of perpendicularly positioned leaf springs
- Can move easily in the lateral direction without a vertical change to the specimen position if sufficient stiffness in the normal direction exists
- Force generation decoupled from the force measurement
- Application and measurement of lateral forces without lateral movement possible
|Test load, max. Fmax, standard1||Approx. 20||Approx. 2||Approx. 0.2||N|
|Test load, min. Fmin, standard1||Approx. 2||Approx. 0.2||Approx. 0.05||mN|
|Digital resolution, force measurement||≤ 0.2||≤ 0.02||≤ 0.002||μN|
|Background noise, force measurement||≤ 202||≤ 23||≤ 0.23||μN|
|Displacement, max.||Approx. 2001||Approx. 2001||Approx. 2001||μm|
|Digital resolution, displacement measurement||≤ 0.002||≤ 0.002||≤ 0.002||nm|
|Background noise, displacement measurement (1 σ at 8 Hz)||≤ 0.4||≤ 0.3||≤ 0.3||nm|
|Background noise, displacement measurement (1 σ at closed loop module)||≤ 0.2||≤ 0.2|
|Oscillation frequency, max.||300||300||300||Hz|
|Max. frequency for stiffness evaluation||75||75||25||Hz|
|Data acquisition rates||40||40||40||kHz|
|Max. force amplitude of oscillation||> 100||> 100||> 100||mN|
- Compression (e.g. instrumented indentation test) and tensile (e.g. adhesion measurements on liquids)
- At 2 N, ≤ 65 at 20 N
- Signal-to-noise ratio 106
- Only in conjunction with the QCSM software module
|Test load, max. (Fmax), lateral1||approx. 2||N|
|Digital resolution, force measurement||≤ 0.02||μN|
|Background noise, force measurement||≤ 6||μN|
|Travel, max.1||approx. 75||μm|
|Digital resolution, displacement measurement||≤ 0.002||nm|
|Background noise, displacement measurement||≤ 0.5||nm|
- compression and tensile
Various optic options
As standard, the tandem microscope and 50x lens is included in the ZHN scope of supply A 50x lens with extended working distance is available as an option. In addition, there is the option to integrate a 5x lens or a white light interferometer as a second lens.
Nanoindentation and atomic force microscopy (AFM) can be combined in a single system to enable comprehensive, (semi) automated analysis. As a first step the atomic force microscope measures the surface roughness; this helps to define the minimum indentation depth. The specimen is then positioned under the nanoindenter to allow a mechanical analysis to be performed at the same location. In the final step this location can be moved back below the AFM to allow characterization and understanding of stress-induced properties such as material “pile-up” and “sink-in” or cracks around the indent. These effects may then influence the values obtained for hardness and Young's modulus.
Advantages of the optics
- 50x objective lens - the optical path is directed to two cameras via beam-splitters and intermediate lenses
- Within the optical image it is possible to
define measuring points
- measure distances and perimeters
- review and display existing measuring points at the push of a button
- control lighting and image parameters
- show scales and recording times
- Elimination of mechanical lens-changing enables high positioning-accuracy and rapid switching between magnifications
- High-quality imaging is possible even for low-reflection surfaces such as glass
- Autofocus function establishes the correct height for a sharp image
- Automatic generation of images of measuring points (programmable)
- Overview image composed of individual images with large depth of field