Hardness is a characteristic of any material, be it plastic or metal. It can be defined as the resistance of a material to indentation. The hardness of the material is determined by measuring the permanent depth of the indentation. When force and intender is applied on the material, the metal gets a mark. The smaller the indentation, the harder is the material. The hardness of the material is tested by measuring the depth or the area of the indentation by different hardness testing methods.
The key principle of any hardness test method is measured by forcing an indenter into the sample surface by measuring the dimensions of the indentation. The hardness of any material depends on the combination of its yield strength, tensile strength and elasticity. There are a number of benefits offered by hardness testing machines. Some of them are listed below:
Types of hardness tests
- It is easy to operate hardness testing machines.
- Testing different materials on hardness testing machines is an inexpensive option.
- The results related to the hardness of any material can be generated quickly.
- Hardness testing machines can be used for materials of different shapes and sizes.
According to the loading force and indentation, hardness test can be classified in different forms such as macro, micro and nano: Macro-hardness tests:
These include hardness tests such as Rockwell, Brinell and Vickers. These tests are widely used for testing hardness of different materials. The indenting forces of macro-hardness tests range somewhere between 50N to 30000N.Micro-hardness tests:
Vickers and Knoop hardness tests fall in the category of micro-hardness tests. These tests are used in applications where the hardness of coatings, surface hardness is to be measured in a multi-phase material. In the case of these tests, small diamond pyramid is used as the indenter and it has a small force of 10 to 1000gf.Nano-hardness tests:
These tests use minor loads of about 1 nano for measuring the hardness of different materials. The result of these tests is also calculated by measuring the depth of indentation.
Superior quality Hardness Testing Machines can be sourced from Material Testing Machine Suppliers and Manufacturers.