Metal testing is a process or procedure used to check composition of an unknown
metal
A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...
lic substance. There are destructive processes and nondestructive processes. Metal testing can also include, determining the properties of newly forged
metal alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...
s. With many
chemical-property databases readily available, identification of unmarked pure, common metals can be a quick and easy process. Leaving the original sample in complete, re-usable condition. This type of testing is nondestructive. When working with alloys (forged mixtures) of metals however, to determine the exact composition, could result in the original sample being separated into its starting materials, then measured and calculated. After the components are known they can be looked up and matched to known alloys. The original sample would be destroyed in the process. This type of testing is destructive.
Destructive testing (DT)
In this kind of testing, the material undergoes mechanical testing and is discarded thereafter. Test results are compared with specifications. Subtypes include:
* Bend test
* Impact test – Further categorised as
Charpy test and
Izod test
* Hardness test
*
Tensile test
Tensile testing, also known as tension testing, is a fundamental materials science and engineering test in which a sample is subjected to a controlled tension until failure. Properties that are directly measured via a tensile test are ultim ...
* Fatigue test
* Corrosion resistance test
* Wear test
Nondestructive testing (NDT)
Raw and finished material undergoes testing according to code specifications such as
ASME
The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "continuing ...
Boiler and Pressure Vessel Code Section V. The tested material is not damaged by the test. Subtypes include:
* Visual testing
*
Dye penetrant inspection
Dye penetrant inspection (DP), also called liquid penetrate inspection (LPI) or penetrant testing (PT), is a widely applied and low-cost inspection method used to check surface-breaking defects in all non-porous materials (metals, plastics, or cer ...
*
Magnetic particle inspection
*
Radiographic testing
*
Ultrasonic testing
Ultrasonic testing (UT) is a family of non-destructive testing techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ...
* Leak testing
* Eddy current testing
* Remote field electromagnetic testing
* LR UT
See also
*
Metallurgical assay
A metallurgical assay is a compositional analysis of an ore, metal, or alloy, usually performed in order to test for purity or quality.
Some assay methods are suitable for raw materials; others are more appropriate for finished goods. Raw pre ...
References
Metalworking
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