Description
Universal Hardness Testing for research and industry.
Overall View:
Hardness test, which is done in different ways, is considered as a part of none-destructive
tests. The hardness test is performed as an indentation and this test
model is often performed by impacting a sample that is placed on a rigid support.
A mandrel with a fixed and specific shape presses on the sample under static load.
Depending on the type of test, the hardness is expressed with a number that is
inversely proportional to the depth of the effect caused by the specific load and
mandrel; In other words, it is proportional to the average load on the effect surface.
The usual methods of Rockwell, Brinell, and Vickers hardness test.
٭ Hardness measurement by Brinell method (HB): In this method, a spherical
shot (pellet) with a standard diameter is pressed on the surface of the sample
and finally the hardness is determined by measuring the average diameter of
the effect under a microscope.
٭ Hardness measurement by Vickers method (HV): In this method, an object
in the form of a square-base pyramid, where the angle between the opposite
faces of the pyramid is 136 degrees, is used, and finally, the average diameter
of the effect is measured under a microscope and the hardness is determined.
٭ Hardness measurement by Rockwell method (HR): It is used to measure the
hardness of relatively hard materials and there are fifteen types. For example,
shot (pellet) Rockwell applies force with the help of shots, and diamond Rockwell
applies force on the surface of the sample with the help of a diamond.
Finally, the hardness value is shown from the depth of penetration.
