What is the Brinell hardness method?
Brinell hardness method is an optical method that works by measuring the intensity of indentation that is caused by an indenting material.
Brinell hardness method applies an indenter that is spherical in shape, unlike the Vickers hardness method that applies the use of pyramid-shaped indenter that is pressed on a specimen.
It is a method that is used in determining the Brinell hardness.
It is commonly used to test specimens whose structure are too coarse or that have a very rough surface in which other methods cannot be used for them, for example, forgings, casting of metals and etc.
The size or amount of indent caused by Brinell indenter on the surface of a particular specimen or workplace can be used to determine the resistance of the material or specimen to indentation.
This is estimated with a ball with a defined diameter and a test force of defined intensity.
What procedure does Brinell hardness test entail?
Basically, Brinell hardness requires a specimen (workpiece) and spherical indenter.
This spherical intender would be pressed into the particular material that is being tested.
Thereafter, the indentation size is measured.
The degree to which the specimen is affected by the spherical indenter in terms of the impression left by the indenter, reveals the property of the material, or its hardness to simply put.
To test the hardness of material using Brinell hardness strategy there must an indenter with a specific size and weight.
This means that the test load or intender must be predetermined in terms of size, diameter, and weight.
This predetermined indenter is applied into carbide ball which is also of a predetermined diameter.
This is held for a specified or predetermined period of time and then taken away from the surface of the specimen when the scheduled duration is complete.
Thereafter, the impression caused by the indenter is measured with an optical system or Brinell microscope which is specially made for that specific purpose.
The optical system is across nothing less than two diameters – usually perpendicular to one another.
Moreover, the results from the measurement are averaged.
To determine the Brinell hardness according to ISO 6506, you will need to know the amount of the applied force and the area of the surface of the residues caused by the indent on the surface.
So, to calculate the area of the surface of the residues caused by spherical indentation, both diagonals that are at a right angle to one another are averaged, owing to Brinell indents which is constantly not perfectly round.