Hardness testing generally governs the resistance of material displays to perpetual distortion by infiltration of another tougher material. Hardness refers to the vigour needed to cut through the film to the substratum when testing coatings. All hardness tests comprise the application of a specifically shaped indenter that is firmer than the material under testing. This testing is a mechanical test for physical properties used to scrutinize structures, materials advancement, and engineering design.
Various test methods are used globally to determine a material’s hardness with varying suitability for metals, aluminium, steel, cast iron, or plastics. The indenters have different forms, each one specifically designed for the material it is testing. Shape variables include cone, ball, and a pyramid. Testing is extensively used for development control and scrutiny. The result is used in approximating mechanical properties like ductile strength. This process is carried out using testing machines that comprise an indenter imposed into test matter over a certain duration.
Several hardness testing methods are acceptable globally, namely:
• Rockwell Hardness Test
This test requires an indenter that is diamond cone-shaped.
• Knoop Hardness Test
This test is performed by putting force to a rhombus-shaped indenter over a certain duration. Careful measurement is required.
• Vickers Hardness Test
This test is performed by applying measured force to an indenter over a certain duration. The indenter is a square-shaped diamond pyramid.
• Brinell Hardness Test
This test generally uses a carbide ball, again over a specified time. It leaves a circular indent upon removal.