Hardness is the metal’s ability to resist the introduction or breakdown. The metal’s hardness gives an idea of its tensile strength. Therefore, the hardness measurement is carried out by means of any penetrator type pressed into the surface of the tested subject. Depending on the hardness measurement method, either diameter, or depth of the impression is measured. Hardness can be measured also by means of various electronic or ultrasonic devices testing, but generally, it is the pressing.
It is easy to determine the metal hardness, first of all, thanks to a huge number of methods which can use for hardness test. Let’s consider the main three methods of the hardness measurement: Brinell method, Rockwell method and microhardness measurement. The main distinction between these three methods consists in the size of the impression. The impressions resulted from the test according to Brinell have the largest sizes, and at the microhardness measurement they are the smallest.
The Brinell’s method is widely applied to the hardness measurement of metal procurements and materials. It is well suitable for these purposes as the hole occupies significantly large space, fixing problems of the localized solid and soft inclusions in metal. The typically higher loadings which are used during the hardness measurement according to Brinell’s method promote and decrease in the errors due to the surface defects.
Prior to the Brinell’s test it is necessary to prepare the surface, namely to polish or to smooth out a surface before receiving rather flat surface in the test zone. The surface has to be also rather smooth that there was perhaps exact measurement of the impression’s size.
When carrying out testing by Brinell’s method the penetrator is pressed under the weight of freight with the target weight into the tested sample of the surface. After removal of loading the measurement of the print diameter the Prior to the Brinell’s test it is necessary to prepare the surface, namely to polish or to smooth out a surface before receiving rather flat surface in the test zone. The surface has to be also rather smooth that there was perhaps exact measurement of the impression size. due to scaled magnifying glass is carried out. Knowing the size and type the penetrator, the applied loading and diameter of the impression is possible to determine the Brinell hardness number (HB).
