Kõvadusmõõtjad

Kõvadusmõõtjad are instruments used to measure the hardness of materials. Hardness is a measure of a material's resistance to localized plastic deformation, such as scratching or indentation. Different types of hardness testers exist, each employing a specific method to quantify this property.

One common method is indentation hardness testing, where a standardized indenter is pressed into the material's surface under a specific load. The size or depth of the resulting indentation is then measured to determine the hardness value. Popular indentation hardness scales include Rockwell, Brinell, and Vickers. Rockwell hardness testing uses a diamond cone or steel ball indenter and measures the depth of penetration. Brinell hardness uses a hardened steel ball and measures the diameter of the indentation. Vickers hardness employs a diamond pyramid indenter and measures the diagonal length of the indentation.

Another method is scratch hardness testing, which assesses a material's resistance to scratching. The Mohs scale, commonly used for minerals, is an example of a scratch hardness scale, where minerals are ranked based on their ability to scratch one another.

The choice of hardness tester depends on the material being tested, its expected hardness range, and the required accuracy. These instruments are crucial in quality control, material science research, and manufacturing to ensure that materials meet specified performance requirements.