Wear - Measurement


Today there exist a couple of standard test methods for different types of wear to determine the amount of material removal during a specified time period under well-defined conditions.
The ASTM International Committee G-2 attempts to standardise wear testing for specific applications, which are periodically updated. The Society for Tribology and Lubrication Engineers (STLE) has documented a large number of frictional wear and lubrication tests. But all test methods have inbuilt limitations and do not give a true picture in every aspect.
This can be attributed to the complex nature of wear, in particular "industrial wear", and the difficulties associated with accurately simulating wear processes.(ref4)

A standard result review for wear tests, defined by the ASTM International and respective subcommittees such as Committee G-2, should be expressed as loss of material during wear in terms of volume. The volume loss gives a truer picture than weight loss, particularly when comparing the wear resistance properties of materials with large differences in density.
For example, a weight loss of 14 g in a sample of tungsten carbide + cobalt (density = 14000 kg/m³) and a weight loss of 2.7 g in a similar sample of aluminium alloy (density = 2700 kg/m³) both result in the same level of wear (1 cm³) when expressed as a volume loss. The inverse of volume loss can be used as a comparable index of wear resistance.
Standard wear tests are only used for comparative material ranking of a specific test parameter as stipulated in the test method. For more realistic values of material deterioration in industrial applications it is necessary to conduct wear testing under conditions simulating the exact wear process.(ref4)

The working life of an engineering component is expired when dimensional losses exceed the specified tolerance limits. Wear, along with other ageing processes such as fatigue and creep in association with stress concentration factors such as fracture toughness causes materials to progressively degrade, eventually leading to material failure at an advanced age.
Wear in industrial applications is one of a limited number of fault factors in which an object loses its usefulness and the economic implication can be of enormous value to the industry.(ref 4)

The Archard Equation is the classic wear prediction model - see Bisson

Read more about this topic:  Wear

Other articles related to "measurement, measurements":

Inch (disambiguation) - Units
... Inch as a measurement of rain, measured by a rain gauge Inch of mercury, unit of pressure Inch of water, unit of pressure Scottish inch, Scottish unit of measurement Column inch, unit of publication ...
Electrical Capacitance Tomography
... the interior of an object from external capacitance measurements ... Potential applications include the measurement of flow of fluids in pipes and measurement of the concentration of one fluid in another, or the distribution of a solid in a fluid ... Although capacitance sensing methods were in widespread use the idea of using capacitance measurement to form images is attributed to Maurice Beck and co-workers at UMIST in ...
Measurement - Definitions and Theories - Quantum Mechanics
... In quantum mechanics, a measurement is an action that determines the location of an object, its momentum, its polarity (if it is a photon), etc ... Before a measurement is made, the wavefunction of what is to be measured gives the range of probabilities for the outcomes of measurement, but when a ... The unambiguous meaning of the measurement problem is an unresolved fundamental problem in quantum mechanics ...
Correction For Attenuation
... coefficient from the weakening effect of measurement error" (Jensen, 1998), a phenomenon also known as regression dilution ... In measurement and statistics, it is also called disattenuation ... The correlation between two sets of parameters or measurements is estimated in a manner that accounts for measurement error contained within the estimates of those parameters ...
Measurement Tower
... A measurement tower is a free standing tower or a removed mast, which carries measuring instruments with meteorological instruments such as thermometers and wind velocity measurers ... Beside measurement towers, which are equipped with meteorological measuring instruments, there are also measuring towers for measuring the radiation pattern of antennas ...

Famous quotes containing the word measurement:

    That’s the great danger of sectarian opinions, they always accept the formulas of past events as useful for the measurement of future events and they never are, if you have high standards of accuracy.
    John Dos Passos (1896–1970)