Materials testing yields data that characterise the material properties of test specimens and components exposed to mechanical, thermal or chemical influences. Test methods also serve to assess the technological properties. Such methods provide objective, characteristic data and are performed at every phase of the materials' production and processing.
Test methods can be divided into two main groups:
- Destructive test methods
Physical und chemical testing
- Non-destructive test methods
Destructive test methods
Mechanical-technological testing is the collective term for any materials testing which clarifies the suitability of a material for, or under, various conditions, and also provides information about its processability.
Occupying a central position within the group of mechanical test methods are the strength and toughness tests and the "linear-elastic fracture mechanics" test methods for determining fracture toughness. The most important groups of test methods are:
- Static short-time testing:
> tensile test, compression test,
> bend test, torsion test.
- Static long-time testing:´
> creep rupture test,
> relaxation test.
- Dynamic short-time testing:
> impact test,
> tensile shock test.
- Dynamic long-time testing:
> fatigue test,
> single-step, multistep and repeat test.
- Hardness testing:
> static hardness test methods
Brinell hardness test,
> hardness testing at elevated temperatures.
- Fracture-mechanical testing
> determination of critical fracture toughness,
> determination of crack extension,
> determination of the J-integral,
> determination of crack resistance curves,
> fracture-mechanical testing in media that trigger stress corrosion cracking.
Physical and chemical testing
The physical and chemical tests include
- Wet-chemical methods (titration),
- Spectral analysis,
- X-ray fluorescence analysis,
- Microprobeanalysis e.g.glow discharge optical emission spectroscopy, electron probe microanalysis, Auger electron spectroscopy, secondary neutral mass spectroscopy, secondary ion mass spectroscopy.
Metallographic tests for the macro- and microstructure include
- Light microscopy,
- Electron microscopy, e.g. scanning electron microscopy, transmission electron microscopy, atomic force and scanning tunnelling microscopy,
- Thermal analysis,
- Jominy test.
Collective name for a series of tests to determine the corrosion resistance of metals in a corrosive medium such as air, seawater, or acids and caustic solutions, for example. In addition to long-time outdoor testing, short-time laboratory scale tests provide information after just a few days or weeks about the behaviour of a material when exposed to corrosive attack.
- Tekken test,
- Lehigh test,
- CTS (Controlled Thermal Severity) test,
- Implant test.
- Bend test,
- Wire reverse bend and torsion tests,
- Deep drawing test,
- Internal pressure test for hollow bodies,
- Expansion and ring bend tests for tubes,
- Bend test for fusion butt welds,
- Machinability tests,
- Cutting tool endurance tests (testing of tool life at elevated temperature and of wear life, plunger-cut test),
- Wear test
Das ist der Oberbegriff für alle Werkstoffprüfungen, die Werkstoffungleichmäßigkeiten anzeigen, ohne das Werkstück zu beschädigen.
These include methods of the following type:
- Mechanical, e.g. for hardness testing (dynamic hardness testing: drop hardness test, scleroscope hardness test)
- Penetrant, for surface defect inspection, e.g. immersion in oil that can also contain fluorescent substances
- Thermal, e.g. measurement of elevated thermal resistivity in imperfections
- Acoustic, e.g. ultrasonic test
- Optical, e.g. spark test
- Electrical and electromagnetic, e.g. measurement of electrical conductivity
- Magnetic, e.g. magnetic particle test
- Radiographic, e.g. X-ray radiation test
- Chemical, e.g. spot test