Mikrohärteprüfung

Mikrohärteprüfung is a method used to measure the hardness of materials on a very small scale. It is particularly useful for testing thin films, coatings, or small components where traditional hardness testing methods would be too destructive or inaccurate. The principle of microhardness testing involves indenting the surface of the material with a precisely shaped indenter under a controlled load. The size and shape of the indentation left after the indenter is removed are then measured, and this measurement is used to calculate the microhardness value.

The most common type of microhardness tester is the Vickers hardness tester. It uses a square-based diamond pyramid indenter. The load applied is typically very low, ranging from a few grams up to several kilograms. Other types of indenters, such as the Knoop indenter, which has a rhombic shape, are also used, especially for brittle materials or when only shallow indentations are desired. The microhardness value is usually expressed in Vickers hardness (HV) or Knoop hardness (HK) units.

The advantages of microhardness testing include its ability to assess hardness variations across a material's cross-section, identify surface hardening effects, and evaluate the properties of individual phases or grains within a microstructure. It is widely applied in various industries, including metallurgy, materials science, electronics, and automotive manufacturing, for quality control, research and development, and failure analysis. Careful preparation of the sample surface is crucial for obtaining accurate and repeatable results, often involving polishing to a mirror-like finish.