Scribd
Upload
39 views2 pages

Mechanical Testing of Materials

Mechanical material tests are performed under various loads and environmental conditions to evaluate properties like fatigue, fracture, and crack growth. Microscopic characterization is used to examine deformation and damage before and after testing. Characterization of ceramic materials is performed at multiple scales using techniques like X-ray diffraction, electron and ultrasound microscopy, to examine properties like microstructure, phase transformations, and effects of deformation and corrosion. Ceramic materials are used in multilayer armor systems due to their high compressive strength and hardness, where the ceramic layer dissipates projectile energy through fragmentation and the backing layer absorbs residual kinetic energy.

Uploaded by

Saurabh Rathod
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
39 views2 pages

Mechanical Testing of Materials

Mechanical material tests are performed under various loads and environmental conditions to evaluate properties like fatigue, fracture, and crack growth. Microscopic characterization is used to examine deformation and damage before and after testing. Characterization of ceramic materials is performed at multiple scales using techniques like X-ray diffraction, electron and ultrasound microscopy, to examine properties like microstructure, phase transformations, and effects of deformation and corrosion. Ceramic materials are used in multilayer armor systems due to their high compressive strength and hardness, where the ceramic layer dissipates projectile energy through fragmentation and the backing layer absorbs residual kinetic energy.

Uploaded by

Saurabh Rathod
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 2

1) https://www.dlr.de/wf/en/desktopdefault.

aspx/tabid-2451/3644_read-5424/

Mechanical Testing of Materials


Mechanical material tests are performed under various loads, which can be uniaxial but also
biaxial. Measurements are possible in air, vacuum, and corrosive environments at varying
temperature ranges (-196° up to +1,400°C).

A special expertise of the group is fatigue and fracture mechanics testing of all engineering
materials including metals, ceramics, composites and multi-material hybrids. Investigations
of crack growth behavior with determination of the threshold ΔKth, monitoring of da/dN -
ΔK-curves, determination of crack resistance curves, and fracture toughness at different
temperatures are part of the testing portfolio.
The results from mechanical testing are evaluated involving microscopic
characterization of the material before and after testing in order to investigate changes
such as deformation, damage, crack growth, and failure.

2) https://www.dlr.de/wf/en/desktopdefault.aspx/tabid-11981/admin-1/9631_read-18986/
Characterization of Ceramic Materials
Characterization is performed by means of state-of-the-art analytic methods on a very broad
length scale: atomic or crystal structures are investigated be means of X-ray or electron
diffractometry which reveal grain orientations, strains, and phase transformations. Imaging
methods such as scanning and transmission electron microscopy reveal the microstructures
of materials and effects caused by deformation, corrosion, and the like.
A more macroscopic examination of materials and components is performed by non-
destructive methods such as scanning ultrasound analysis or X-ray computed tomography.
Standard characterization methods include thermal conductivity, thermal expansion, micro-
hardness and permeability.

3) Due to their high compressive strength and hardness,

many ceramic materials are used as the first component in a

multilayered armor system. Its main function is to dissipate

a significant amount of the projectile energy by means of

the fragmentation of the projectile tip as well as by the

fragmentation of the ceramic layer14,20-25. The second layer, just

behind the ceramic, may be either a high strength polymeric

fiber, such as aramid, or a high molecular weight polyester,

as composed of polymeric matrix composites and fibers. The function of this intermediate layer is in holding
the
fragments of the first layer, composed by a fragile material,
as well as helping in the energy dissipation of the projectile

In ceramic-based armour, the


3) ceramic is usually applied at the strike face and is supported by a
backing layer. When the hardness of a ceramic material is high
enough it can erode the AP core of an impacting bullet and spread
the impact load over a wide surface of the backing material. Both
these effects help the backing material to absorb the residual kinetic
energy of the bullet

You might also like